VSH Specification FAA-P-3015A - Draft 2026_Feb_8 v1.pdf

FAA-P-3015A Draft

Feb 8, 2026

Procurement Specification For

Voice Switch Headset and Handset (VSH)

Office of Primary Responsibility

Technical Operations

Air Traffic Voice Switch Systems Team

AJW-154

XX/XX/XXXX

ii

Federal Aviation Administration

800 Independence Avenue, SW

Washington, DC 20591 iii

PROCUREMENT SPECIFICATION

For

Voice Switch Headset and Handset (VSH) iv

Change Record

Change Letter

Description of Change

(including section number if a small change)

Date Changed by

(include office symbol)

Approved by

(include office symbol)

A General update to address requirements

5/18/2015 D. Smith, AJW-173

X Refine requirements various D. Smith, AJW-173

X Requirements scrub, validate, update 10/7/2025 D.Smith AJW-154

X Reference to figure corrected 2/08/2026 DSmith AJW-154 v

Table of Contents

1.0 SCOPE

1.1 Overview

1.2 Operations Concept

2.0 APPLICABLE DOCUMENTS

2.1 FAA Documents

2.2 Non-FAA Government Documents

2.3 Non-Government Documents

3.0 REQUIREMENTS

3.1 System (Item) Definition

3.1.1 Functional Layouts

3.1.2 Interfaces

3.1.3 Major Components

3.1.4 FAA/Government Furnished Equipment

3.2 Performance

3.2.1 Operational Performance

3.2.2 Headset Operational Performance

3.2.3 Handset Operational Performance

3.2.4 Wireless Operational Performance

3.2.5 Headset Jack Module Splitter

3.2.6 Alternate PTT Device (APTTD)

3.2.7 Physical Requirements - General

3.2.8 Headset Physical Requirements

3.2.9 Handset Physical Requirements

vi

3.2.10 Reliability/Availability

3.2.11 Maintainability

3.2.12 Environments

3.3 System Characteristics

3.3.1 Safety

3.3.2 Interchangeability

3.3.3 Human Factors

3.4 Logistics

3.4.1 Documentation

3.4.2 Training

3.4.3 Spare / Repair Parts

3.4.4 Support and Test Equipment

3.4.5 Packaging, Handling, Storage, and Transportation (PH&T)

3.4.6 Engineering Support

3.4.7 Configuration Management

4.0 VERIFICATION CORRELATION

4.1 Verification Methods

4.2 Design/Type Test

4.3 Production Test

4.4 Technical Field Test and Evaluation

4.4.1 Headsets

4.4.2 Handsets

5.0 DELIVERY AND TRANSITION

5.1 Packaging, Handling, Storage, and Transportation (PHS&T)

6.0 NOTES

6.1 Special Definitions

6.2 Definitions of Existing Hardware

6.2.1 Voice Switch Interface

vii

6.3 Special Considerations

6.4 Special Guidelines

6.5 Acronyms

6.6 Glossary

Explanatory Notes (Reserved)

6.7 Explanatory Notes

viii

List of Tables Table No. Page

TABLE 3-1. LIST OF VOICE COMMUNICATION SYSTEMS

TABLE 3-2. ELECTROSTATIC DISCHARGE FAILURE CRITERIA

TABLE 3-3. VOLTAGE AND CURRENT LIMITS FOR ELECTROSTATIC DISCHARGE

ix

List of Figures Figure No. Page

FIGURE 3-1. HEADSET (NON-WIRELESS) ASSEMBLY DIAGRAM (SIX-WIRE)

FIGURE 3-2. HANDSET ASSEMBLY DIAGRAM (SIX-WIRE)

FIGURE 3-3. ALTERNATE PUSH-TO-TALK DEVICE DIAGRAM………… ………………6

FIGURE 3-4. ELECTROSTATIC DISCHARGE TEST WAVEFORM…………….. ……..…………….…40

x

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1.0 SCOPE

This specification provides requirements for Federal Aviation Administration (FAA) Voice Switch Headset and Handset equipment.

1.1 Overview

Section 1.0 (this section) of this specification describes the scope of this specification, gives an overview of this specification, and provides an operational concept for the VSH. It is descriptive in nature and contains no binding requirements.

Section 2.0 of this specification lists the cited documents within subsequent sections as a part of binding requirements.

Section 3.0 describes system performance and physical requirements.

Section 4.0 lists specialized verification requirements not covered in detail by the contract statement of work under which this specification is issued.

Section 5.0 provides requirements for preparation for delivery.

Section 6.0 contains an acronym listing, glossary and a description of existing equipment. It is descriptive in nature and contains no binding requirements.

1.2 Operations Concept

Headsets, handsets, wireless headsets, and ancillary devices provided under this specification are to be used by Air Traffic Control Specialists (ATCS) in the conduct of ATC operations.

The ATCS use headsets and handsets in proximity to their controller positions where displays and controls of various ATC systems are visible and accessible. They will be used in the operational and administrative areas of ATC facilities, including Airport Traffic Control Towers (ATCT), Terminal Radar Approach Control (TRACON), Air Route Traffic Control Centers (ARTCC), Flight Service Stations (FSS), Flight Service Stations, the Air Traffic Control Systems Command Center (ATCSCC), Combined Enroute Radar Approach Control (CERAP), and future air traffic control facilities. They are the principal device for ATCS’ to transmit and receive voice communications among pilots, other ATCS’s, and supervisors.

Headsets, handsets, and other ancillary devices interface with FAA voice communications systems (VCS) including voice switching systems, voice over IP communication enterprise (VOICE) and backup communications systems providing high quality, intelligible, transmission and reception of voice communications over radios and telephones from/to the ATCS. These communications systems provide a standardized connection and power as well as volume and sidetone controls for the headsets and handsets. Air/Ground (A/G) Voice transmissions from the ATCS using headsets and handsets are enabled by Push-to-talk (PTT) signaling which defaults to the off position. Headset PTT buttons may be locked in the engaged position, and at the option of the ATCS provide an open microphone or “hot mic” and continuous PTT signaling. Depending on configuration of the voice communications system, Ground/Ground (G/G) voice transmissions from the ATCS may or may not require the need to engage PTT.

Headsets and handsets are provided in multiple models and styles, each with the same capabilities and designed to accommodate controller needs for an adjustable fit and long-term wear over the course of eight-hour, or longer, work shifts. Headset models include those that fit into the operator’s ear canal (ITU-T P.57 earpiece), outside of the operator’s ear canal, and on the operator’s outer ear in an ear cushion style (ITU-T P57 supra-aural earphone).

Microphones (non-noise canceling and noise canceling) are adjustable to fit individual users.

All models of the headsets and handsets include circuitry designed to ensure that acoustic levels does not exceed specified Occupational Safety and Health Administration (OSHA) permissible noise exposure limits.

Certain operational needs at NAS facilities require use of wireless/cordless headsets for voice communications. Several wireless/cordless devices are used in close proximity to each other.

The operating range of the cordless/wireless headsets is up to 150 feet. Performance specifications of the wireless devices are identical to corded headsets, with the exception of certain parameters introduced by wireless technologies. Headsets worn by the ATCS are interchangeable with between corded and wireless versions.

A headset jack module splitter is provided that facilitates connecting two headset/handset devices to a single jack module of a ATC voice switch positions. The headset splitter provides the capability to train controllers on an ATC position, or to add additional controllers on a position as necessary. The headset splitter consists of a pre-empting jack and a secondary jack. The headset splitter operation does not require power to be provided by the ATC voice communication system, other than microphone bias.

Headsets are of a modular design to maintain economic lifecycle support and to adapt to a range of site needs, including the length of cords. Modular design also permits interchangeability of headset components to meet user and facility needs. All models of headsets and handsets are functionally interchangeable with respect to operation with ATC voice communications systems such that a single headset or handset is capable of interfacing with multiple communications systems. Headsets and handsets are plug-compatible so that either will function properly at an ATCS workstation.

Headset and handset equipment is user-maintainable without the need for special tools. They require no special training for ATC use. Technical and operational documentation required for headsets and handsets is minimal. VSH components and accessories can be easily removable and replaceable by users. Headsets and handsets require no periodic maintenance actions beyond cleaning. Spare units, components and accessories are provided at each site.

Headsets are testable, with an easy to operate testing device, to confirm the proper operation of its amplitude protection capability. Replacement units, components, and accessories are obtainable from a centralized depot that may provide for repairs, if economically feasible.

2.0 APPLICABLE DOCUMENTS

The following documents form a part of this specification to the extent specified herein. In case of any discrepancy between these documents and specific requirements of this specification, this specification shall be the superseding document unless otherwise directed by the government.

2.1 FAA Documents

FAA-G-2100H Electronic Equipment, General Requirements

FAA STD 019 Lightning and Surge Protection, Grounding, Bonding and Shielding Requirements for Facilities and Equipment

FAA-STD-013 Quality Control Program Requirements

HF-STD-001B FAA Human Factors Design Standard

2.2 Non-FAA Government Documents

29 CFR 1910 Code of Federal Regulations Title 29, Part 1910

47 CFR 15 Code of Federal Regulations Title 47, Part 15

MIL-HDBK-217 Reliability Predication for Electronic Equipment

MIL-STD-130 Identification and Marking of U.S. Military Property

FED-STD-313 Material Safety Data, Transportation Data and Disposal Data for Hazardous Materials Furnished to Government Activities

FED-STD-595 Colors

2.3 Non-Government Documents

IEC 61000-4-2 Testing and Measurement Techniques

IEEE 1652-2016 IEEE Standard for Translating Head and Torso Simulator Measurements from Eardrum to Other Acoustic Reference Points

ITU-T Recommendation P.64 Determination of Sensitivity/Frequency Characteristics of Local Telephone Systems

ITU-T Recommendation P.57 Artificial Ears

ITU-T Recommendation P.58 Head and Torso Simulator for Telephonometry

ITU-T Recommendation P.862 Perceptual Evaluation of Speech Quality (PESQ): An Objective Method for End-to-End Quality Assessment of Narrow-Band Telephone Networks and Speech Codecs

ITU-T Recommendation P.863 Perceptual Objective Listening Quality Prediction

3.0 REQUIREMENTS

3.1 System (Item) Definition

The Voice Switch Headset (VSH) equipment specified herein are types of headset assemblies, handset assemblies, and other critical communication devices designed for use as an FAA standard and used with communications systems at Air Traffic Control (ATC) facilities.

3.1.1 Functional Layouts

a. Figure 3.1 depicts the functional assembly of the non-wireless headset.

FIGURE 3-1. Headset (non-Wireless) Assembly Diagram (Six-Wire)

b. Figure 3.2 depicts the functional assembly of the handset.

c. Reserved.

d. Reserved.

e. Figure 3.3 depicts the functional assembly of the alternate push-to-talk device

(APTTD).

FIGURE 3-2. Handset Assembly Diagram (Six-Wire)

FIGURE 3-3. Alternate Push-to-Talk Device Diagram

3.1.2 Interfaces

Headsets and handsets specified herein shall interface with FAA voice communications systems listed in TABLE 3-1.

TABLE 3-1. List of Voice Communication Systems

VOICE VSCS

IVSR VTABS

RDVS STVS

ETVS VSBP

CCS-W ICSS-Type 3

Alaska Flight Service AAC

3.1.3 Major Components

3.1.3.1 Headset Components

f. The headset shall consist of two separate modules, an upper module and a lower module. (See Figure 3.1.)

g. The upper module shall consist of the upper cable assembly, ear capsule (speaker or transducer), headband, eartip / earbud / ear cushion, clothing clip, and microphone (non-noise canceling or noise canceling), dependent on the model.

h. The lower module shall consist of a switch case, pushbutton, lower cable assembly, wrist loop, and belt clip.

i. The headset assembly shall include non-noise canceling microphone component based upon model.

j. The headset assembly shall include noise-canceling (proximity) microphone component based upon model.

k. Receive amplification, active amplitude regulation, etc., shall typically be part of the lower module.

l. The upper module and lower module shall be connectorized for interchangeability.

m. The lower module shall connect with all upper modules without use of additional cables, pendants, adapters, or dongles.

n. Accessories shall consist of clothing clip, eyeglass clip, ear cushions, storage container, microphone replacement parts, wind screen, earpieces, earbuds, ear cushions (supra-aural and circum-aural), molded earpiece “kit”,as dictated by design.

o. A method to obtain a custom molded earpiece shall be included in the VSH program.

p. The VSH shall provide Hearing Aid Compatible (HAC) headsets.

q. All requirements herein shall apply to HAC headsets, except the receive characteristics specifically conflicting with HAC design and performance techniques and methods (telecoil, acoustic pickup, etc).

3.1.3.2 Handset Components

a. Handset assemblies shall consist of telephone-type handset and cable assembly.

(See Figure 3.2.)

b. The handset assembly shall include non-noise canceling microphone component based upon model.

c. The handset assembly shall include transmit noise canceling microphone component based upon model.

d. The handset assembly shall include a PTT switch.

e. The handset assembly shall include a transmit amplifier.

f. The handset assembly shall include a receiver or receiver amplifier.

g. The VSH shall provide Hearing Aid Compatible (HAC) handsets.

h. All handset requirements herein shall apply to HAC handsets, except the receive characteristics specifically conflicting with HAC design and performance techniques and methods (telecoil, acoustic pickup, etc.)

3.1.3.3 Wireless Components

3.1.3.3.1 Basestation

r. The basestation module shall consist of all interface components necessary to connect to the ATC voice switch as defined herein.

s. The basestation module shall provide its own power connection to an AC outlet.

t. The basestation module shall consist of all components, controls, and user adjustments required to properly interface with the ATC voice switch and the wireless remote.

u. The basestation module shall consist of a receptacle to mount and charge its associated remote device.

v. The basestation module shall provide ability to charge at least one additional remote device battery.

3.1.3.3.2 Remote

a. The remote module shall consist of a switch case, PTT pushbutton, belt clip, visual indicators, battery, controls, and volume adjustment.

b. The remote module and headset upper module shall be connectorized for interchangeability.

c. The remote module shall contain all components necessary for wireless communication with the basestation module.

d. The lower module shall connect with all upper modules without use of additional cables, pendants, adapters, or dongles.

3.1.3.4 Jack Module Splitter Components

a. The headset jack module splitter shall consist of splitter module, cable assemblies, and power connector.

b. The headset jack module splitter shall provide a PTT preemption jack.

c. The headset jack module splitter shall provide its own power independent of the voice switch.

d. Console top surface mounting accessories shall be provided for temporary mounting

e. As ordered by the government, console mounting brackets shall be provided to allow permanent or semi-permanent top surface mounting, in-console mounting, or under surface mounting.

3.1.3.5 Support and Test Equipment

3.1.3.5.1 Amplitude Limiting Test Device

a. The VSH shall provide test equipment, orderable by the Government, capable of determining proper (pass/fail) operation of the amplitude limiting functionality requirements set forth in 3.2.2.2.6 and 3.2.3.2.6.

3.1.4 FAA/Government Furnished Equipment

None.

3.2 Performance

3.2.1 Operational Performance

a. The operational performance requirements herein apply to the following VSH major components, unless noted otherwise:

(1) Headset

(2) Push-To-Talk and Amplifier device(s)

(3) Handset

(4) Wireless components

(5) Jack Module Splitter components defined in 3.1.3

(6) Reserved

b. The performance requirements for the VSH major components shall be met over the range of normal operating conditions.

c. The output of the microphone shall be measured at the PJ-7 connector, or other connector type as ordered.

d. All requirements shall be met from 300 Hz to 3.3 kHz..

e. The following requirements apply only to non-wireless VSH components:

(1) The VSH shall not employ sidetone (electronic or acoustical)

(2) The VSH shall not include user-adjustable transmit level control.

(3) The VSH shall not include user-adjustable receive volume control.

f. The VSH shall not cause unexpected operation at any voice switch operator position listed in TABLE 3-1.

g. The VSH shall be designed with the microphone always connected to the amplifier such that only energizing the external circuit is required to enable audio transmissions.

h. Wiring shall conform to the circuit diagram of FIGURE 3-1 or FIGURE 3-2, six-wire circuit, as applicable.

i. Wiring shall be accomplished in accordance with FAA-G-2100H.

j. The electro acoustical performance requirements of this specification shall be based upon the Brüel & Kjær (B&K) Type 4128C Head and Torso Simulator (HATS) test equipment.

(1) Other HATS systems used to verify compliance with this specification must conform to ITU P.57 Head and Torso Simulator for Telephonometry.

k. The electro acoustical performance requirements of this specification shall be based upon the B&K Type 4939 ¼” Free-Field Reference Microphone test equipment.

l. All sound pressure levels (SPLs) given herein are free-field, unless otherwise noted.

m. Translation of HATS measurements to free-field shall conform with IEEE 1652-2016.

3.2.1.1 Power

a. The headset and handset shall fully comply with this specification when provided a DC voltage between 3 V and 52 V.

b. The headset and handset shall fully comply with this specification with a supply current of 10mA to 130mA.

c. External power (battery, AC adapter, etc.) may be provided for wireless and jack module splitter components.

3.2.2 Headset Operational Performance

3.2.2.1 Transmit Characteristics

a. The headset shall meet all performance requirements with an effective microphone load impedance of 50 ± 22.5 ohms at 1 kHz.

b. The headset shall meet all performance requirements with an amplifier DC input current of 10mA to 130mA.

c. The headset shall meet all performance requirements with a DC input voltage of 3 V to 52 V.

d. As ordered by the Government, the VSH contractor shall provide a headset equipped with a non-noise canceling microphone.

e. As ordered by the Government, the VSH contractor shall provide a headset equipped with a noise canceling (proximity) microphone.

3.2.2.1.1 Sensitivity

a. An input signal of 1kHz at 94 dBSPL1 shall produce an output level of -11 dBm ± 4dB into 600 ohms.

3.2.2.1.2 Linearity

a. . An input signal change of 1.0 dBA SPL shall produce a change in output level of 1.0 dB (± 0.3 dB) over the input signal range of 74 to 110 dBSPL.

3.2.2.1.3 Noise

a. A white noise input signal level of less than 40 dBSPL shall produce an output level ≤ 35 dBrnC.

3.2.2.1.4 Voice Quality

a. The headset shall provide a minimum narrowband Mean Opinion Score - Listening Quality Objective (MOS-LQOn) score of 3.8 in accordance with ITU-T P.863, Perceptual Objective Listening Quality Prediction for all microphone types and styles.

1 Unless otherwise noted, all output characteristics of the microphone shall be determined using an acoustical input level of 94 dBSPL measured at 25mm on centerline axis from the equivalent lip plane of the sound source. The microphone shall be positioned in situ, i.e., positioned according to published instructions for operational use.

b. The MOS-LQOn score requirement of 3.2.2.1.2.a. shall be obtained in combination with the sensitivity requirement of 3.2.2.1.

c. The MOS-LQOn score shall be obtained with the headset positioned in situ on the

HATS.

3.2.2.1.5 Frequency Response

a. The transmit amplifier frequency range shall be 300 Hz to 3.3 kHz.

b. The output level of the transmit amplifier shall not vary more than ± 6dB from the 1 kHz point, for a constant input level of 94 dBSPL1 from 400 Hz to 1.5 kHz applied to the microphone.

c. The output level of the transmit amplifier shall not vary more than ± 10dB from the 1 kHz point, for a constant input level of 94 dBSPL1 from 1.5 kHz to 3.0 kHz applied to the microphone.

3.2.2.1.6 Harmonic Distortion

a. The total harmonic distortion of the transmit amplifier shall be ≤ 5% for an input level of 94 dBSPL1 from 400 Hz to 2.5 kHz.

3.2.2.1.7 Noise Cancellation (Transmit)

a. When ordered by the Government, the headset shall provide a noise canceling microphone function.

b. The noise-canceling function shall be internal to the headset or microphone.

c. The noise-canceling function shall meet all performance characteristics except as otherwise identified in this section below.

3.2.2.1.7.1 Sensitivity of Noise Canceling Headsets

a. The noise canceling microphone, when subjected to an input signal of 1kHz at 94 dBSPL at 25mm from the equivalent lip plane, shall produce an output level at least 12 dB below the level obtained in requirements statement 3.2.2.1.1.a when the headset noise canceling microphone face is placed normal and on axis at a distance of 12 inches from the equivalent lip plane.

b. The noise-canceling microphone, when subjected to a sound level of 300 Hz at 88 dBSPL (measured on the face of the microphone) originating from a sound source located 12 inches away from (far sound source) and normal to the microphone face, shall produce an output not less than 12 dB below an identical sound source located 25 mm away from (near sound source) and normal to the microphone face.

c. The headset noise-canceling microphone output from the far sound source shall remain at least 12dB below the output from the near sound source as the far source is moved to any other point on the surface of an imaginary sphere of a 12 inch radius with the microphone located at the center.

3.2.2.1.7.2 Linearity and Noise

a. The noise-canceling headset shall satisfy the requirements statement 3.2.2.1.2.

b. The noise-canceling handset shall satisfy the requirements statement 3.2.2.1.3.

3.2.2.1.7.3 Frequency Response

a. The output level of the noise-canceling transmit amplifier shall be at least 9 dB below the levels, for a constant input level (94 dBSPL at 25mm from the equivalent lip plane) of 400 Hz to 3.0 kHz applied to the microphone, as obtained in requirements statement 3.2.2.1.1, when the headset noise canceling microphone face is placed normal and on axis at a distance of 12 inches from the equivalent lip plane.

3.2.2.1.8 Transmit Amplifier Gain Switching2

d. Transmit amplifiers may employ gain reduction for input levels ≤ 74 dBSPL.

e. There shall be no spurious switching transients, oscillations, or audible anomalies during operation of the headset.

3.2.2.1.8.1 Attack (Turn-on) Time

a. The transmit level shall reach to within 3dB of its steady state value, for a change of input from 70 dBSPL to 94 dBSPL, as defined in requirements statement 3.2.2.1.1.

in less than 8ms.

3.2.2.1.8.2 Release (Turn-off) Time

a. The transmit level shall reach to within 3dB of its steady state value in 50ms (± 10ms), for a change of input from 94 dBSPL to 70 dBSPL.

2 Transmit Amplifier Gain Switching requirements apply to transmit amplifiers that electronically change gain based upon input level to the microphone. Measurements are made at 25mm from the equivalent lip plane on the centerline axis.

3.2.2.1.9 Warm-up Time

a. The transmit output shall reach at least 6dB of its steady-state value within 150ms, from the time that DC power is applied to the connector as defined in 3.2.1.c.

3.2.2.2 Receive Characteristics

a. Unless otherwise stated, all requirements in Section 3.2.2.2 shall apply to at least one frequency band setting available with the device, without changing the setting, if the headset is equipped with user-adjustable frequency response controls.

b. As ordered by the Government, the headset shall provide a high-gain receive capability as an option.

3.2.2.2.1 Input Impedance

a. The receiver input impedance shall be no greater than 600 ohms (+10%).

b. The receiver shall meet all performance requirements with a source impedance of 10 to 600 ohms.

3.2.2.2.2 Sensitivity

a. An input signal of -26 dBm (into 600 ohms)at 1kHz shall produce an output ≥ 92 dB SPL, for in-the-ear headsets (ITU-T P.57 insert earphone).

b. For monaural ear cushion style headsets (ITU-T P.57 supra-aural or circum-aural earphones), an input signal level of -26 dBm (into 600 ohms) dBmat 1 kHz shall produce an output ≥ 83 dBSPL.

c. For binaural ear cushion style headsets, (ITU-T P.57 supra-aural or circum-aural earphones) an input signal level of -26dBm (into 600 ohms) at 1 kHz shall produce an output ≥ 80 dBSPL.

3.2.2.2.3 Sensitivity – High Gain Receive

a. An input signal of -26 dBm (into 600 ohms) at 1kHz shall produce an output ≥ 97 dB SPL, for in-the-ear headsets (ITU-T P.57 insert earphone).

b. For monaural ear cushion style headsets (ITU-T P.57 supra-aural or circum-aural earphones), an input signal level of -26dBm (into 600 ohms) at 1 kHz shall produce an output ≥ 88 dBSPL.

c. For binaural ear cushion style headsets, (ITU-T P.57 supra-aural or circum-aural earphones) an input signal level of -26dBm (into 600 ohms) at 1 kHz shall produce an output ≥ 85 dBSPL.

3.2.2.2.4 Frequency Response

a. The headset receive frequency range shall be 300 Hz to 3.3 kHz.

b. A constant input signal level of -26dB dBm at 400 Hz to 3.0 kHz shall produce an output level within +8 to -6 dB with respect to the value measured at the 1 kHz point.

3.2.2.2.5 Harmonic Distortion

a. The total harmonic distortion shall ≤ 5%, with an input signal of -26 dBm in the frequency range of 400 Hz to 3.0 kHz.

3.2.2.2.5.1 Isolation (Feedback)

a. The transmit amplifier output shall be ≤-40 dBm (into 600 ohms), with a receive input signal of -10 dBm (into 600 ohms) at 1 kHz.

3.2.2.2.6 Acoustical Protection

a. The headset shall provide protection to the operator from harmful levels defined in

29 CFR 1910.

b. The headset shall limit the audio voltage such that no sound pressure levels in excess of 115 dBA SPL (continuous, free field) appear to the ear.

c. The headset shall limit the audio voltage such that no sound pressure levels in excess of 125 dBA SPL (impulse, free field) appear to the ear.

d. The response (attack) time of the amplitude-limiting feature described in 3.2.2.5.b and 3.2.2.2.5.c shall be less than 6ms to obtain its steady state protection level (± 3dB).

e. As an option ordered by the Government, headset amplitude protection shall limit the audio voltage so that no sound pressure levels in excess of 105 dBA SPL (continuous, free field) appear to the ear.

3.2.2.3 Push-to-Talk (PTT)

a. The PTT switch contacts of the headset shall be rated for 0.5 ampere, 52 V DC.

b. The maximum DC resistance when the PTT switch is closed shall be ≤ 25 ohms.

c. The minimum DC resistance when the PTT switch is open shall be greater than 20 megohms.

3.2.2.3.1 PTT Debounce

d. PTT switch closure or opening shall constructed to minimize or eliminate transients, or “bounce”.

a. PTT switch contact closure or opening shall reach steady-state (± 1%) within 2ms.

3.2.3 Handset Operational Performance

3.2.3.1 Transmit Characteristics1

a. The handset shall meet all performance requirements with an effective microphone load impedance of 50 ± 22.5 ohms at 1 kHz.

e. The handset shall meet all performance requirements with an amplifier DC input current of 10mA to 130mA.

f. The handset shall meet all performance requirements with a DC input voltage of 3 V to 52 V.

g. As ordered by the Government, the VSH contractor shall provide a handset withboth a non-noise canceling microphone option, as ordered by the Government.

3.2.3.1.1 Sensitivity

a. An input signal of 1kHz at 88 dBSPL3 shall produce an output level of -17 dBm ±4 dB.

3.2.3.1.2 Linearity

a. An input signal change of 1.0 dBA SPL shall produce a change in output level of

1.0 dB (± 0.3 dB) over the input signal range of 74 to 110 dBSPL.

3.2.3.1.3 Noise

a. A white noise input signal level of less than 40 dBSPL shall produce an output level ≤ 35 dBrnC.

3.2.3.1.4 Voice Quality

a. The headset shall provide a minimum narrowband Mean Opinion Score - Listening Quality Objective (MOS-LQOn) score of 3.8 in accordance with ITU-T P.863, Perceptual Objective Listening Quality Prediction for all microphone types and styles.

3 Unless otherwise noted, all output characteristics of the microphone shall be determined using an acoustical input level of 88 dBSPL measured at 25mm on centerline axis from the equivalent lip plane of the sound source. The handset test position shall be either the manufacturer’s recommended test position (RTP) or the standard test position (STP) with the application force of 10N, in accordance with ITU-T Recommendation P.64, Annex E. The definition of the manufacturer’s recommended test position (RTP) must be defined if using the RTP.

b. The MOS-LQOn score requirement of 3.2.3.1.4.a shall be obtained in combination with the sensitivity requirement of 3.2.3.1.1.

c. The MOS-LQOn score shall be obtained with the headset positioned in situ on the

HATS.3

3.2.3.1.5 Frequency Response

a. The transmit amplifier frequency range shall be 300 Hz to 3.3 kHz.

b. The output level of the transmit amplifier shall be +4 to -6 dB from the 1 kHz point, for a constant input level of 88 dBSPL from 400 Hz to 1.5 kHz applied to the microphone.

c. The output level of the transmit amplifier shall be +6 to -8 dB from the 1 kHz point, for a constant input level of 88 dBSPL from 1.5 kHz to 3.0 kHz applied to the microphone.

3.2.3.1.6 Harmonic Distortion

a. The total harmonic distortion of the transmit amplifier shall ≤ 5%, for an input level of 88 dBSPL from 400 Hz to 2.5 kHz.

3.2.3.1.7 Noise Canceling Handset

a. The noise canceling function shall be internal to the handset.

b. The noise canceling function shall meet all performance characteristics except as otherwise identified in Section 7 and its subsections.

3.2.3.1.7.1 Sensitivity

a. An input signal of 1kHz at 98 dBSPL shall produce an output level of -10 dBm ±4 dB (into 600 ohms).

b. When subjected to an input signal of 1kHz at 98 dBSPL at 25mm from the equivalent lip plane, the noise canceling handset microphone shall produce an output level at least 10 dB below the level obtained in requirements statement 3.2.2.1.1.a. when the handset noise canceling microphone face is placed normal and on axis at a distance of 24 inches from the equivalent lip plane

c. The handset noise-canceling microphone, when subjected to a sound level of 98 dB SPL at 300Hz (measured on the face of the microphone) originating from a sound source located 24 inches away (far sound source) from and normal to the microphone face, shall produce an output not less than 10 dB below an identical sound source located 25 mm away from (near sound source) and normal to the microphone face.

d. The handset noise-canceling microphone output from the far sound source shall remain at least 10 dB below the output from the near sound source as the far source is moved to any other point on the surface of an imaginary sphere of at least a 24 inch radius with the microphone located at the center.

3.2.3.1.7.2 Linearity and Noise

a. The noise-canceling handset shall satisfy the requirements statement 3.2.3.1.2.a.

b. The noise-canceling handset shall satisfy the requirements statement 3.2.3.1.3.a.

3.2.3.1.7.3 Frequency Response

a. The output level of the transmit amplifier shall be at least 10 dB below the levels obtained in requirements statement 3.2.3.1.2.b and c, for a constant input level (98 dBSPL at 25mm from the equivalent lip plane) of 400 Hz to 3.0 kHz applied to the microphone when the headset noise canceling microphone face is placed normal and on axis at a distance of 24 inches from the equivalent lip plane.

3.2.3.1.8 Transmit Amplifier Gain Switching2

a. Transmit amplifiers may employ gain reduction for input levels ≤ 74 dBSPL.

b. There shall be no spurious switching transients, oscillations, or audible anomalies during operation of the headset.

3.2.3.1.9 Attack (Turn-on) Time

a. The transmit level shall be within 3dB of its steady state value, for a change of input from 70 dBSPL to 94 dBSPL, as defined in requirements statement 3.2.3.1.1.a. or 3.2.3.1.7.1.a., as applicable, in less than 8ms.

3.2.3.1.10 Release (Turn-off) Time

a. The transmit level shall be within 3dB of its steady state value in 50ms (± 10ms), for a change of input from 94 dBSPL to 70 dBSPL.

3.2.3.1.11 Warm-up Time

a. The transmit output shall reach at least 6dB of its steady-state value within 150ms, from the time that DC power is applied.

3.2.3.2 Receive Characteristics

3.2.3.2.1 Input impedance

a. The receiver input impedance shall be no more than 600 ohms.

b. The receiver shall meet all performance requirements with a source impedance of 10 ohms to 600 ohms.

3.2.3.2.2 Sensitivity

a. An input signal of -26 dBm (into 600 ohms) at 1 kHz shall produce an output ≥ 88 dBSPL.

3.2.3.2.3 Frequency Response

a. The handset receive frequency range shall be 300 Hz to 3.3 kHz.

b. A constant input signal level of -26 dBm at 400 Hz to 3.0 kHz shall produce an output level within +8 to -6 dB with respect to the value measured at the 1 kHz point.

3.2.3.2.4 Harmonic Distortion

a. The total harmonic distortion shall be ≤ 5%, with an input signal of -26 dBm in the frequency range of 400 Hz to 3.0 kHz.

3.2.3.2.5 Isolation (feedback)

a. The transmit amplifier output shall be ≤ -40 dBm (into 600 ohms), with an input signal of -10 dBm (into 600 ohms) at 1 kHz.

3.2.3.2.6 Acoustical Protection

a. The handset shall provide protection to the operator from harmful levels defined in 29 CFR 1910.95 Table G-16.

b. The handset shall limit the audio voltage such that no sound pressure levels in excess of 115 dBA SPL (continuous, free field) appear to the ear.

c. The handset shall limit the audio voltage such that no sound pressure levels in excess of 125 dBA SPL (impulse, free field) appear to the ear.

d. The response (attack) time of the amplitude-limiting feature described in 3.2.3.3.b and 3.2.3.3.c. shall be less than 1ms to obtain its steady state protection level (± 3 dB).

3.2.3.3 Push-to-Talk (PTT)

a. The PTT switch contacts for handset shall be rated for 0.5 ampere, 52 V DC.

b. The maximum DC resistance when the PTT switch is closed shall be ≤ 25 ohms.

c. The minimum DC resistance when the PTT switch is open shall be greater than 20 megohms.

3.2.3.3.1 PTT Debounce

a. PTT switch closure or opening shall be constructed to minimize or eliminate transients, or “bounce”.

b. PTT switch contact closure or opening shall reach steady-state within 2ms (± 1%).

3.2.4 Wireless Operational Performance

3.2.4.1 Wireless Transmit Characteristics

a. If equipped with multiple transmit modes (e.g., sensitivity adjustments, microphone type settings, etc.) the wireless component shall provide a single transmit mode capable of meeting all performance requirements without changing the setting.

b. If equipped with user adjustable transmit gain settings, the wireless component shall provide a single setting capable of meeting all performance requirements.

c. Audio transmit characteristics for the wireless component shall be in accordance 3.2.2.1.

d. All transmit user adjustments shall be easily located without disassembly of the unit(s).

e. All transmit settings and adjustments shall be non-volatile.

f. Transmit delay (audio) shall not exceed 15ms.

g. Transmit delay (PTT) shall not exceed 50ms.

h. The wireless component must provide a transmit audio narrowband Mean Opinion Score - Listening Quality Objective (MOS-LQOn) score of 3.5 in accordance with ITU-T P.863, Perceptual Objective Listening Quality Prediction, for the greatest usable range.

3.2.4.2 Receive Characteristics

a. If equipped with multiple receive modes (e.g., sensitivity adjustments) the wireless component shall provide a receive mode capable of meeting all performance requirements without changing the setting.

b. If equipped with user adjustable receive gain settings, the wireless component shall provide a single setting capable of meeting all performance requirements.

c. Audio receive characteristics for the wireless component shall be in accordance 3.2.2.2.

d. On/off and receive volume controls shall be located on the remote module.

e. All receive user adjustments shall be easily located without disassembly of the unit(s)..

f. All receive settings and adjustments shall be non-volatile.

g. Receive delay (audio) shall not exceed 15ms.

3.2.4.3 Wireless Link

3.2.4.3.1 General Requirements

a. The VSH wireless components shall not cause electromagnetic interference with, nor affected by electromagnetic interference from, the site at which it is installed.

b. The VSH wireless components must ensure that all equipment is compliant with Class B digital devices per CFR 47, Chapter 15.

c. The VSH wireless component must provide a security feature equivalent to at least 64-bit encryption for the audio path.

d. Crosstalk shall not exceed 55dB.

e. The transmit and receive output shall reach at least 6dB of its steady state value within 150 ms from the time that the wireless link is established.

3.2.4.3.2 Range and User Density

a. The VSH wireless component must provide up to 50 unique users located at a single facility (air traffic control room).

b. The VSH wireless component must provide a non-interfering, usable range of 150 feet for a single wireless component.

c. The VSH wireless component must provide a non-interfering usable range of 100 feet for 5 individual wireless components.

3.2.4.4 Controls and Indicators

3.2.4.4.1 General

a. The remote unit must disengage PTT when the unit is turned off.

b. The remote unit must disengage PTT when out of range for 15 seconds.

c. The remote unit must disengage PTT when an error condition exists.

3.2.4.4.2 Audible Indicators

d. Audible indicators shall be provided to the headset receive path.

e. Audible indicators shall be of a volume and frequency such as not to interfere with normal communications.

f. Audible indicators shall be unique to define a state of operation for the wireless system.

g. Audible indicators shall be provided for on/off setting.

h. Audible indicators shall indicate remote module volume setting during adjustment.

i. Audible indicators shall indicate transmit volume setting during adjustment.

j. The remote unit may provide non-interfering audible indications to the user when unit is near its range limit.

k. The remote unit shall provide audible indications to the user when the unit is out of range.

l. The remote unit shall provide audible indicators to the user for general error conditions.

m. The remote unit shall provide a non-interfering audible indicator for a low battery state.

3.2.4.4.3 Visible Indicators

a. Each wireless component (basestation and remote) must provide visible indicators to indicate operation state of the device.

b. Each wireless component (basestation and remote) must provide continuous visible indicators to indicate units are powered.

c. The basestation module must provide continuous visible indication that a battery is charging

d. The basestation module must provide continuous visible indication that a battery is fully charged.

e. The remote unit must provide continuous visible indicators to indicate successful link synchronization state.

f. The remote unit must provide continuous visible indicators to indicate unsuccessful link synchronization state.

g. The remote unit must provide continuous visible indication when PTT is depressed.

3.2.4.5 Power

a. The wireless components shall be powered in accordance with the requirements of 3.2.1.

b. The remote unit shall be battery powered.

c. The remote unit shall operate without the need for charging for at least 8 hours.

d. The battery charger must fully charge a battery in less than 2 hours.

e. The battery charger shall be integrated into the basestation module.

f. The remote unit shall be able to be charged without disassembly

g. The charging function shall employ fail-safe capability.

h. The charging function shall indicate battery charging conditions.

3.2.4.6 Sidetone

a. The wireless remote module shall employ locally generated sidetone.

b. The wireless remote module shall provide sidetone between 8 dB and 12 db down from the transmit level.

c. The total harmonic distortion of the sidetone shall be ≤ 5% for an input level of 94 dBSPL from 400 Hz to 2.5 kHz.

d. The wireless remote module sidetone delay shall be less than 5 ms.

e. The wireless basestation shall suppress sidetone originating from the voice switch.

f. The wireless basestation module shall provide sidetone suppression of at least 24 dB.

3.2.5 Headset Jack Module Splitter

a. The headset splitter must provide capability to operate two VSH devices from a single voice switch jack input.

b. The splitter shall provide a jack capable of pre-empting transmit audio of the other jack.

c. When the pre-empting or priority jack detects PTT from its associated VSH device, the transmit audio of the other jack shall be terminated.

d. The headset splitter preempting/priority jack shall be clearly labeled.

e. Both jacks and the plug connections shall be non-polarized.

f. The headset splitter shall not sink current from the voice switch when connected unless a headset/handset device is connected to the splitter.

g. The headset splitter shall provide all receive and sidetone audio to both headset jacks.

h. The headset splitter shall provide transmit audio originating from either jack to the voice switch, unless preemption defined in 3.2.5.c applies.

i. The headset splitter shall provide unity gain in the transmit path when a single headset device is connected.

j. The headset splitter shall isolate transmit audio between the two jacks.

k. The headset splitter shall provide unity gain in the receive path when a single VSH device is connected.

l. The headset splitter receive audio level reduction shall not exceed 3dB when two headset devices of equal impedance are connected.

m. If equipped with a battery, the headset splitter shall provide visible battery health indicators.

n. If equipped with a battery, replacement of the battery will not require disassembly of the headset splitter.

o. If equipped with a battery, the VSH shall provide a charger function for the headset splitter battery.

p. The headset splitter shall provide a visible power on/off indication.

3.2.6 Alternate PTT Device (APTTD)

a. As ordered by the government, the VSH shall provide an alternate PTT device (APTTD). See Figure 3.3.

b. The APTTD shall meet all PTT requirements prescribed in paragraph 3.2.2.3.

c. The APTTD shall provide a pushbutton to activate PTT signaling.

d. The APTTD pushbutton shall provide momentary contact closure when depressed.

e. Depression of the APTTD pushbutton shall close a pair of contacts that activate circuitry within the voice switching system.

f. The APTTD shall be connected to the headset lower module or handset via a pendant cable, dongle, or adapter cable.

g. The VSH shall provide a lower headset module connectorized such that it is capable to interface the APTTD.

h. Use of an APTTD shall not interfere with PTT activation of the lower headset module PTT pushbutton.

i. The APTTD cable and connector shall not exceed 3 feet in length.

3.2.7 Physical Requirements - General

a. The VSH construction shall permit the headset / handset to be used with either ear.

b. The VSH shall be constructed using materials and processes that preclude irritation of the users’ skin.

c. The VSH shall remain unaffected by interaction with users’ skin oils and perspiration.

d. Metals shall be of a corrosion-resistant type.

e. Wiring shall be in accordance with FAA-G-2100H.

f. Headsets, headset modules, handsets, handset modules, wireless modules, and headset jack module splitters shall be marked in accordance with part or identifying number, revision, date of manufacture, and manufacturer’s name or symbol in accordance with MIL-STD-130N, paragraph 4. Order of precedence for markings shall be model number, revision, and date code of manufacture.

g. Manufacturer-warranted items shall be marked in accordance with MIL-STD-130N paragraph 5.7, first sentence only.

h. Items that have been repaired or refurbished shall be marked in accordance with MIL-STD-130N, paragraph 5.5 including bullets (a) and (b). The VSH design shall exclude the use of hazardous materials defined in FED-STD-313D that could cause toxic exposures during operation, maintenance, or fire.

The VSH design shall exclude the use of hazardous materials that require special disposal procedures.

3.2.7.1 Colors

a. The primary VSH color, including connecting plug, shall be in accordance with Federal Standard 595, Color 37038 (Black).

b. The handset may be provided in optional colors.

3.2.7.2 Physical Interface to Voice Switch / Plug Termination

a. The VSH Headset Lower Module shall be provided with a long-frame 6-wire plug with dual tip/ring/sleeve PJ-7 or equivalent plug termination.

b. The VSH Handset shall be provided with a long-frame 6-wire plug with dual tip/ring/sleeve PJ-7 or equivalent plug termination

c. The VSH Wireless Basestation Module shall be provided with a long-frame 6-wire plug with dual tip/ring/sleeve PJ-7 or equivalent plug termination

d. The VSH Jack Module Splitter shall be provided with a long-frame 6-wire plug with dual tip/ring/sleeve PJ-7 or equivalent plug termination

e. The VSH Jack Module Splitter shall be provided with two dual long frame 6-wire plug with dual tip/ring/sleeve PJ-7 or equivalent plug receptacles.

f. The plug and receptacles shall be non-polarized.

3.2.8 Headset Physical Requirements

3.2.8.1 Cables

3.2.8.1.1 Upper Module Cable

a. The overall length of the cable, including connectors, shall be between 44 inches and 50 inches from lower module to upper module.

b. Strain relief shall be provided at both ends of the upper module cable(s).

c. The cable shall withstand ≥ 100,000 flexes to 45° in each direction on a ¼-inch mandrel with a suspended 0.5 lb. weight.

d. Flexibility shall permit conformance to a 3/8 inch mandrel with a 0.5 lb. weight attached to the loose end of a six-inch section.

e. The cable shall include a quick disconnect connector to interface with the lower module.

3.2.8.1.2 Lower Module Cable

a. Headset lower module cable shall be of a retractile design.

b. The retractile ratio of the lower module cable shall be greater than or equal to 5:1.

c. Excluding the wireless components, headset lower modules shall be provided with cables in optional lengths of 10 feet, 15 feet, and 25 feet.

d. Strain relief shall be provided at both ends of the lower module cable.

e. The cable shall withstand ≥ 100,000 flexes to 45° in each direction on a ¼-inch mandrel with a suspended 1.0 lb. weight.

f. Wiring shall conform to the circuit diagram of FIGURE 3-1, six-wire circuit.

3.2.8.2 Push-To-Talk (PTT)

a. The headset shall provide a pushbutton to activate PTT signaling.

b. The headset pushbutton shall be capable of being activated by the user’s thumb.

(1) Alternative pushbutton activation such as activation by the user’s forefinger, shall be permitted, as ordered by the Government.

c. The headset pushbutton shall provide momentary contact closure when depressed.

d. The headset pushbutton shall permit locking, as ordered by the Government, in the depressed state.

(1) The pushbutton shall be designed so that the locking feature can be inhibited.

e. Depression of the pushbutton to either the momentary or the locking position shall be used to close a pair of contacts, which activates circuitry within the voice switching system.

f. The PTT switch shall withstand ≥ 200,000 depressions with free release without failure.

g. The PTT switch closure or opening shall constructed to minimize or eliminate transients, or “bounce”.

h. The PTT switch contacts shall remain disengaged when the switch case is dropped from a height of 12” on the pushbutton side at angles including 0°, 45°, 90°, 135°, and 180°.

3.2.8.3 Headset Upper Module

3.2.8.3.1 Headset Upper Module Types

3.2.8.3.1.1 In-the-Ear

a. The VSH shall provide a monaural In-the-Ear as described in ITU-T P.57 Insert Earphones.

b. The VSH shall provide an headset upper module ear capsule that that is wholly supported by the operator’s outer ear and interfaces by the use of an earpiece placed inside of the operator’s ear canal (intra-aural, or insert earphone).

c. The VSH shall be provided with user-replaceable earpieces of soft, resilient, material in at least 3 sizes.

d. One set of earpieces consisting of one earpiece of each size shall be provided as a set with each headset.

e. Earpieces shall be manufactured of non-allergenic material.

f. The headset shall accommodate connection of a user-provided molded earpiece.

3.2.8.3.1.2 Supra-Aural

a. The VSH shall provide monaural ear cushion (muff-style) headset type as described in ITU-T P.57 Supra-aural earphone.

b. The VSH shall provide a binaural model of the Supra-Aural earphone.

c. The VSH shall be provided in an ear-cushion style the fits on the operator’s outer ear in a monaural design.

d. The VSH shall be provided in an ear-cushion style the fits on the operator’s outer ear in a binaural design.

e. VSH ear-cushion style unit shall have a headband with an adjustment greater than or equal to 1.0 inch.

f. Headband adjustments shall provide a locking feature.

g. Ear cushion position on the headband shall be adjustable by greater than or equal to

1.0 inch vertically.

h. Ear cushions shall be manufactured from non-allergenic material.

i. Ear cushions shall be user-replaceable.

3.2.8.3.1.3 Circum-Aural

a. The VSH shall provide monaural ear cushion (muff-style) headset type as described in ITU-T P.57 Circum-aural earphone.

b. The VSH shall provide a binaural model of the Circum-Aural earphone.

c. The VSH shall be provided in an ear-cushion style that encapsulates the operator’s outer ear in a monaural design.

d. The VSH shall be provided in an ear-cushion style that encapsulates the operator’s outer ear in…