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.

Effects of the Carrier Phrase on Word Recognition Performances by Younger and Older Listeners Using Two Stimulus Paradigms

“…Other relations gleaned from the dataset included the following: (1) a comparison of recognition performances on the VA-1 and VA-2 versions of NU-6 demonstrated for both listeners groups that at the higher presentation levels similar performances were achieved, whereas the VA-2 version was slightly better (easier) at the presentation levels at which performances were <50%; (2) there were 27 females and 21 males in the OHL group with the same (a) mean ages, (b) mean pure-tone thresholds except at 4000 Hz at which the mean male threshold was 16.5 dB lower, and (c) recognition performances that were systematically, but nonsignificantly, 6-8% better by the female listeners at all presentation levels; and (3) a comparison with data from a previous study (Wilson 52 ) involving the VA-1 speaker demonstrated performances to be 2.4-dB (YNH) and 6.0-dB (OHL) better in the current study, which was reasonable agreement considering the different procedures and calibrations used in the two studies.…”

“…In effect, the level or amplitude of the target word is not specified, only estimated. A more detailed discussion of the amplitude calibration issues associated with the speech materials used in audiology is provided in a previous article (Wilson 52 ) that includes reference to earlier comments on the calibration of speech signals by Davis 11 and Stevens et al 43…”