The individual recognition performances in the competing message are plotted in Figure 7 as a function of the HFPTA of the test ear for the nonveterans (Figure 7(a)) and veterans (Figure 7(b)).
Abbreviations: ANOVA = analysis of variance, EHLS = Epidemiology of Hearing Loss Study, HFPTA = high-frequency pure tone average, HHIE-S = Hearing Handicap Inventory for the Elderly-Screening (version), HL = hearing level, LE = left ear, NU-6 = Northwestern University Auditory Test No.
Mean three-frequency pure tone average (PTA) at 500, 1,000, and 2,000 Hz; mean high-frequency PTA (HFPTA) at 1,000, 2,000, and 4,000 Hz; and mean word-recognition scores on Northwestern University Auditory Test No.
Accordingly, the HFPTAs were also derived for each participant group and are listed in Table 5.
The data in the right-most columns associated with the HFPTA show that only 8 participants with normal hearing based on the HFPTA had hearing aids compared with 40 participants with normal hearing based on the traditional PTA.
Because the HFPTA was a more appropriate pure tone metric than the traditional PTA, we calculated DSI using the HFPTA as the hearing impairment component in the DSI definition.
The overall prevalence of DSI in veterans at the VA medical center in Mountain Home was 5.0 or 7.4 percent, depending on whether the traditional PTA or the HFPTA was used to define hearing impairment.
The HFPTA is a better pure tone metric than the traditional PTA in that it places more emphasis on the higher frequencies, which are important for communication, especially in background noise [21-23,38,40-44].
Abbreviations: CI = confidence interval; dB HL = dB hearing level; DSI = dual sensory impairment; HFPTA = high-frequency pure tone average; ICD-9-CM = International Classification of Diseases-9th Revision, Clinical Modification; PTA = pure tone average; RR&D = Rehabilitation Research and Development; VA = Department of Veterans Affairs; VHA = Veterans Health Administration, WHO = World Health Organization.