A Comparison of Word-Recognition Performances on the Auditec and VA Recorded Versions of Northwestern University Auditory Test No. 6 by Young Listeners with Normal Hearing and by Older Listeners with Sensorineural Hearing Loss Using a Randomized Presentation-Level Paradigm.

Abstract

The Auditec of St. Louis and the Department of Veterans Affairs (VA) recorded versions of the Northwestern University Auditory Test No. 6 (NU-6) are in common usage. Data on young adults with normal hearing for pure tones (YNH) demonstrate equal recognition performances on the two versions when the VA version is presented 5 dB higher but similar data on older listeners with sensorineural hearing loss (OHL) are lacking. To compare word-recognition performances on the Auditec and VA versions of NU-6 presented at six presentation levels with YNH and OHL listeners. A quasi-experimental, repeated-measures design was used. Twelve YNH (M = 24.0 years; PTA = 9.9-dB HL) and 36 OHL listeners (M = 71.6 years; PTA = 26.7-dB HL) participated in three, one-hour sessions. Each listener received 100 stimulus words that were randomized by 6 presentation levels for each of two speakers (YNH, -2 to 28-dB SL; OHL, -2 to 38-dB SL). The sessions were limited to 25 practice and 400 experimental words. Digital versions of the 16, 25-word tracks for each session were alternated between speakers. Each of the 48 listeners had higher recognition performances on the Auditec version of NU-6 than on the VA version. The respective overall recognition performances on the Auditec and VA versions were 71.4% and 64.1% (YNH) and 68.7% and 58.2% (OHL). At the highest presentation levels, recognition performances on the two versions differed by only 0.5% (YNH) and 3.3% (OHL). At the 50% correct point, performances on the Auditec version were 3.2 dB (YNH) and 6.1 dB (OHL) better than those on the VA version. The slopes at the 50% points on the mean functions for both speakers were about 4.9%/dB (YNH) and 3.0%/dB (OHL); however, the slopes evaluated from the individual listener data were steeper, 5.2 to 5.3%/dB (YNH) and 3.3 to 3.5%/dB (OHL). When the individual data were transformed from dB SL to dB HL, the differences between the two listener groups were emphasized. The four functions (2 speakers by 2 listener groups) were plotted for each of the 48 participants and each of the 200 words, which revealed the gamut of relations among the datasets. Examination of the data for each speaker across test sessions, in the traditional 50-word lists, and in the typically used 25-word lists of Randomization A revealed no differences of clinical concern. Finally, introspective reports from the listeners revealed that 91.7% and 83.3% of the YNH and OHL listeners, respectively, thought the Auditec speaker was easier to understand than the VA speaker. Recognition performances on each participant and on each word are presented.