Audiometric Test Frequency

Added: Apr 16, 2009 6:41 am

Determination of the Variability of 8 kHz as an Audiometric Test Frequency Relative to 0.5, 1, 2, 3, 4, and 6kHz

BACKGROUND
Presently, 6 kHz is the highest required test frequency in most U.S. hearing conservation audiometric monitoring programs. Without testing at 8 kHz, it is not possible to determine the presence or absence of a notch at 6 kHz. Worse yet, without testing at 8 kHz, a 6 kHz notch would mimic the appearance of age-related hearing loss (presbyacusis). Because audiologists and occupational hearing conservation technicians are currently taught to look for a 4 kHz notch, it is likely that a noise-induced hearing loss manifested by a 6 kHz notch would be misdiagnosed as presbyacusis. The results of the recent National Health and Nutrition Examination Survey (NHANES) on the hearing of American adults has found the noise notch may occur more commonly at 6 kHz rather than at other frequencies where noise notches may also occur, i.e., 3 and 4 kHz. In a subset of 175 noise-exposed male participants in the NHANES survey, 99 were found to have notches at 6 kHz vs. 14 and 62 at 3 and 4 kHz respectively.

Presently, there is resistance to incorporating 8 kHz as a standard test frequency because of a widely held belief that it is not possible to obtain reliable 8 kHz hearing thresholds. The physiological dimensions and acoustic resonances of the external auditory meatus not withstanding, this belief is not substantiated by data; however, it has assumed an unwarranted acceptance among the audiological community as being true. Pilot analyses of NIOSH data collected during a study of hearing among auto plant workers have demonstrated 8 kHz hearing threshold measures to actually be more reliable than some of the current standard audiometric test frequencies. The proposed effort will be designed to compare the reliability of 8 kHz to current required audiometric test frequencies. If the viability of 8 kHz as a reliable test frequency can be demonstrated, i.e., if 8 kHz hearing thresholds can be measured as accurately as thresholds at other frequencies, then this effort will overcome existing resistance to the use of 8 kHz.

 PROJECT OBJECTIVES
This effort shall determine if 8 kHz is sufficiently reliable as an audiometric test frequency to be incorporated as a standard test frequency during the annual audiometric monitoring component of a hearing loss prevention program.

This shall be accomplished by:
1. Determining the relative reliability of pure tone hearing thresholds as a function of repeated measures taken on the same day.
2. Determining the relative reliability of pure tone hearing thresholds as a function of repeated measures taken on different days.
3. Quantifying the extent to which the reliability of 8 kHz hearing thresholds are similar to or different from hearing thresholds at 0.5, 1, 2, 3, 4, and 6 kHz, for both males and females between the ages of 20 and 69.

The complete solicitation doucment, and reference material, if applicable, will be available for downloading at www.fedbizopps.gov on or about 5/5/2009 and proposals will be due on or about 6/5/2009.  No verbal or written requests for copies will be accepted.  It is the responsibility of the perspective offerors to stay abreast of the additional postings regarding this solicitation at the FedBizOpps internet site. 

No government-wide notes apply.  All vendors must be registered in Central Contractor Registry (CCR) prior to an award of a federal contract.  The website is: www.ccr.gov.

All responsible responsive sources may submit an offer which shall be considered by the agency.

This is a full and open competitive requirement.

NO PHONE CALLS PLEASE.