Richard H. Wilson

The purpose of this study was to examine the prevalence and characteristics of audiograms that are notched (1) at 4,000 Hz and (2) at 3,000, 4,000, and/or 6,000 Hz. Bilateral audiograms from 1,000,001 veterans were obtained from Department of Veterans Affairs archives; after "cleaning" algorithms were applied, 744,553 participants (mean age = 63.5 yr) were included in the 4,000 Hz notch analysis (group 1) and 539,932 participants (mean age = 62.2 yr) were included in the 3,000, 4,000, and/or 6,000 Hz notch analysis (group 2). A notch was defined when the threshold at the notch frequency (3,000, 4,000, or 6,000 Hz) minus the 2,000 Hz threshold and the threshold at the notch frequency minus the 8,000 Hz threshold both were greater than or equal to 10 dB. In group 1, 77.1% did not have a notch at 4,000 Hz. In group 2, 65.3% did not have a notch at 3,000, 4,000, or 6,000 Hz; 12.4% had bilateral notches, 11.7% had left ear notches, and 10.7% had right ear notches. The notches were about twice as deep on the low-frequency side of the notch than on the high-frequency side. The mean left ear and right ear notch depths were about the same (23 dB), with mode notch depths in the 15.0 to 17.5 dB range.

Objective: The purpose was to determine if speech-recognition performances were the same when the speech level was fixed and the noise level varied as when the noise level was fixed and the speech level varied. Design: A descriptive/quasi-experimental experiment was conducted with Lists 3 and 4 of the revised speech perception in noise (R-SPIN) test, which involves high predictability (HP) and low predictability (LP) words. The R-SPIN was modified into a multiple signal-to-noise paradigm (23- to −1-dB in 3-dB decrements) from which the 50% points were calculated with the Spearman-Kärber equation. Study sample: Sixteen young listeners with normal hearing and 48 older listeners with pure-tone hearing losses participated. Results: The listeners with normal hearing performed better than the listeners with hearing loss on both the HP and LP conditions. For both groups of listeners, (1) performance on the HP sentences was better than on the LP sentences, and (2) the mean 50% points were 0.1 to 0.4 dB lower (better) on the speech-variable, babble-fixed condition than on the speech-fixed, babble-variable condition. Conclusions: For practical purposes the ≤ 0.4-dB differences are not considered noteworthy as the differences are smaller than the decibel value of one word on the test (0.6 dB).

Background:The Words-in-Noise Test (WIN) was developed as an instrument to quantify the ability of listeners to understand monosyllabic words in background noise using multitalker babble (Wilson, 2003). The 50% point, which is calculated with the Spearman-Kärber equation (Finney, 1952), is used as the evaluative metric with the WIN materials. Initially, the WIN was designed as a 70-word instrument that presented ten unique words at each of seven signal-to-noise ratios from 24 to 0 dB in 4 dB decrements. Subsequently, the 70-word list was parsed into two 35-word lists that achieved equivalent recognition performances (Wilson and Burks, 2005). This report involves the development of a third list (WIN List 3) that was developed to serve as a practice list to familiarize the participant with listening to words presented in background babble.Purpose:To determine—on young listeners with normal hearing and on older listeners with sensorineural hearing loss—the psychometric properties of the WIN List 3 materials.Research Design:A quasi-experimental, repeated-measures design was used.Study Sample:Twenty-four young adult listeners (M = 21.6 yr) with normal pure-tone thresholds (≤20 dB HL at 250 to 8000 Hz) and 24 older listeners (M = 65.9 yr) with sensorineural hearing loss participated.Data Collection and Analysis:The level of the babble was fixed at 80 dB SPL with the level of the words varied from 104 to 80 dB SPL in 4 dB decrements.Results:For listeners with normal hearing, the 50% points for Lists 1 and 2 were similar (4.3 and 5.1 dB S/N, respectively), both of which were lower than the 50% point for List 3 (7.4 dB S/N). A similar relation was observed with the listeners with hearing loss, 50% points for Lists 1 and 2 of 12.2 and 12.4 dB S/N, respectively, compared to 15.8 dB S/N for List 3. The differences between Lists 1 and 2 and List 3 were significant. The relations among the psychometric functions and the relations among the individual data both reflected these differences.Conclusions:The significant ∼3 dB difference between performances on WIN Lists 1 and 2 and on WIN List 3 by the listeners with normal hearing and the listeners with hearing loss dictates caution with the use of List 3. The use of WIN List 3 should be reserved for ancillary purposes in which equivalent recognition performances are not required, for example, as a practice list or a stand alone measure.

Background:Since the 1940s, measures of pure-tone sensitivity and speech recognition in quiet have been vital components of the audiologic evaluation. Although early investigators urged that speech recognition in noise also should be a component of the audiologic evaluation, only recently has this suggestion started to become a reality. This report focuses on the Words-in-Noise (WIN) Test, which evaluates word recognition in multitalker babble at seven signal-to-noise ratios and uses the 50% correct point (in dB SNR) calculated with the Spearman-Kärber equation as the primary metric. The WIN was developed and validated in a series of 12 laboratory studies. The current study examined the effectiveness of the WIN materials for measuring the word-recognition performance of patients in a typical clinical setting.Purpose:To examine the relations among three audiometric measures including pure-tone thresholds, word-recognition performances in quiet, and word-recognition performances in multitalker babble for veterans seeking remediation for their hearing loss.Research Design:Retrospective, descriptive.Study Sample:The participants were 3430 veterans who for the most part were evaluated consecutively in the Audiology Clinic at the VA Medical Center, Mountain Home, Tennessee. The mean age was 62.3 yr (SD = 12.8 yr).Data Collection and Analysis:The data were collected in the course of a 60 min routine audiologic evaluation. A history, otoscopy, and aural-acoustic immittance measures also were included in the clinic protocol but were not evaluated in this report.Results:Overall, the 1000‐8000 Hz thresholds were significantly lower (better) in the right ear (RE) than in the left ear (LE). There was a direct relation between age and the pure-tone thresholds, with greater change across age in the high frequencies than in the low frequencies. Notched audiograms at 4000 Hz were observed in at least one ear in 41% of the participants with more unilateral than bilateral notches. Normal pure-tone thresholds (≤20 dB HL) were obtained from 6% of the participants. Maximum performance on the Northwestern University Auditory Test No. 6 (NU-6) in quiet was ≥90% correct by 50% of the participants, with an additional 20% performing at ≥80% correct; the RE performed 1‐3% better than the LE. Of the 3291 who completed the WIN on both ears, only 7% exhibited normal performance (50% correct point of ≤6 dB SNR). Overall, WIN performance was significantly better in the RE (mean = 13.3 dB SNR) than in the LE (mean = 13.8 dB SNR). Recognition performance on both the NU-6 and the WIN decreased as a function of both pure-tone hearing loss and age. There was a stronger relation between the high-frequency pure-tone average (1000, 2000, and 4000 Hz) and the WIN than between the pure-tone average (500, 1000, and 2000 Hz) and the WIN.Conclusions:The results on the WIN from both the previous laboratory studies and the current clinical study indicate that the WIN is an appropriate clinic instrument to assess word-recognition performance in background noise. Recognition performance on a speech-in-quiet task does not predict performance on a speech-in-noise task, as the two tasks reflect different domains of auditory function. Experience with the WIN indicates that word-in-noise tasks should be considered the “stress test” for auditory function.

Background:Pure-tone, air-conduction audiograms notched at 4000 Hz have long been considered the signature configuration for noise-induced hearing loss even though there is an extensive literature that does not mesh with this simple explanation. There are many reports of notched audiograms from individuals with no history of noise exposure and, conversely, reports of audiograms with no notches from individuals with a history of noise exposure. Recent reports increasingly suggest that unilateral 4000 Hz notches are common. The prevalence of notched audiograms at 4000 Hz is dependent on the definition of the notch and the population under study.Purpose:To examine the prevalence and characteristics of audiograms that are notched at 4000 Hz.Research Design:Retrospective, descriptive.Study Sample:The participants were 3430 veterans evaluated in the Audiology Clinic at the VA Medical Center, Mountain Home, Tennessee. The mean age was 62.3 yr.Data Collection and Analyses:The data were collected in the course of a 60 min, routine audiological evaluation. In addition to pure-tone audiometry, a history, otoscopy, speech audiometry in quiet and in noise, and aural-acoustic immittance measures were included in the clinic protocol but were not evaluated in this report. A notch was defined when the 4000 Hz threshold minus the 2000 Hz threshold and the 4000 Hz threshold minus the 8000 Hz threshold both were ≥10 dB.Results:Overall the mean LE (left ear) thresholds at 2000, 3000, and 4000 Hz were at hearing levels 2‐3 dB higher than the hearing levels for the corresponding mean RE (right ear) thresholds; the differences were significant. A notched audiogram was observed in 40.6% of the participants in at least one ear with 15.4% having bilateral notches, 28.8% LE notches, and 27.1% RE notches. Unilateral 4000 Hz notches were almost twice as prevalent as bilateral 4000 Hz notches. Viewed as a function of age, notched audiograms were most common (∼35% of the participants) in the 40 and 50 yr groups with a diminishing prevalence in the 60‐80 yr groups. The mean notch depth at 4000 Hz was consistently 20‐26 dB across the seven age groups. In comparison to the thresholds of the audiograms that were not notched, the thresholds of the audiograms with 4000 Hz notches (1) at 250‐2000 Hz were at hearing levels 2‐3 dB lower, (2) at 3000 and 4000 Hz were at hearing levels 8‐17 dB higher, and (3) at 8000 Hz were at hearing levels 3‐4 dB lower; the threshold differences were significant at all frequencies for both ears.Conclusions:The data suggest that unilateral, 4000 Hz notched audiograms are as common or more common than bilateral notched audiograms and that unilateral notched audiograms are equally common for the LE and RE. The prevalence and characteristics of 4000 Hz notched audiograms in this veteran sample are similar to those observed in the population as a whole.

Purpose: To establish normative data for children on the Words-in-Noise Test (WIN; R. H. Wilson, 2003; R. H. Wilson & R. McArdle, 2007). Method: Forty-two children in each of 7 age groups, ranging in age from 6 to 12 years ( n = 294), and 24 young adults (age range: 18–27 years) with normal hearing for pure tones participated. All listeners were screened at 15 dB HL (American National Standards Institute, 2004) with the octave interval between 500 and 4000 Hz. Randomizations of WIN Lists 1, 2, and 1 or WIN Lists 2, 1, and 2 were presented with the noise fixed at 70 dB SPL, followed by presentation at 90 dB SPL of the 70 Northwestern University Auditory Test No. 6 (T. W. Tillman & R. Carhart, 1966) words used in the WIN. Finally, the Peabody Picture Vocabulary Test—Revised (L. M. Dunn & L. M. Dunn, 1981) was administered. Testing was conducted in a quiet room. Results: There were 3 main findings: (a) The biggest change in recognition performance occurred between the ages of 6 and 7 years; (b) from 9 to 12 years, recognition performance was stable; and (c) performance by young adults (18–27 years) was slightly better (1–2 dB) than performance by the older children. Conclusion: The WIN can be used with children as young as 6 years of age; however, age-specific ranges of normal recognition performance must be used.

Background:The most common complaint of adults with hearing loss is understanding speech in noise. One class of masker that may be particularly useful in the assessment of speech-in-noise abilities is interrupted noise. Interrupted noise usually is a continuous noise that has been multiplied by a square wave that produces alternating intervals of noise and silence. Wilson and Carhart found that spondaic word thresholds for listeners with normal hearing were 28 dB lower in an interrupted noise than in a continuous noise, whereas listeners with hearing loss experienced only an 11 dB difference.Purpose:The purpose of this series of experiments was to determine if a speech-in-interrupted-noise paradigm differentiates better (1) between listeners with normal hearing and listeners with hearing loss and (2) among listeners with hearing loss than do traditional speech-in-continuous-noise tasks.Research Design:Four descriptive/quasi-experimental studies were conducted.Study Sample:Sixty young adults with normal hearing and 144 older adults with pure-tone hearing losses participated.Data Collection and Analysis:A 4.3 sec sample of speech-spectrum noise was constructed digitally to form the 0 interruptions per second (ips; continuous) noise and the 5, 10, and 20 ips noises with 50% duty cycles. The noise samples were mixed digitally with the Northwestern University Auditory Test No. 6 words at selected signal-to-noise ratios and recorded on CD. The materials were presented through an earphone, and the responses were recorded and analyzed at the word level. Similar techniques were used for the stimuli in the remaining experiments.Results:In Experiment 1, using 0 ips as the reference condition, the listeners with normal hearing achieved 34.0, 30.2, and 28.4 dB escape from masking for 5, 10, and 20 ips, respectively. In contrast, the listeners with hearing loss only achieved 2.1 to 2.4 dB escape from masking. Experiment 2 studied the 0 and 5 ips conditions on 72 older listeners with hearing loss, who were on average 13 yr younger and more varied in their hearing loss than the listeners in Experiment 1. The mean escape from masking in Experiment 2 was 7 dB, which is 20‐25 dB less than the escape achieved by listeners with normal hearing. Experiment 3 examined the effects that duty cycle (0‐100% in 10% steps) had on recognition performance in the 5 and 10 ips conditions. On the 12 young listeners with normal hearing, (1) the 50% correct point increased almost linearly between the 0 and 60% duty cycles (slope = 4.2 dB per 10% increase in duty cycle), (2) the slope of the function was steeper between 60 and 80% duty cycles, and (3) about the same masking was achieved for the 80‐100% duty cycles. The data from the listeners with hearing loss were inconclusive. Experiment 4 varied the interburst ratios (0, ‐6, ‐12, ‐24, ‐48, and ‐∞ dB) of 5 ips noise and evaluated recognition performance by 24 young adults. The 50% points were described by a linear regression (R² = 0.98) with a slope of 0.55 dB/dB.Conclusion:The current data indicate that interrupted noise does provide a better differentiation both between listeners with normal hearing and listeners with hearing loss and among listeners with hearing loss than is provided by continuous noise.

The Epidemiology of Hearing Loss Study (EHLS) conducted in Beaver Dam, Wisconsin, was a population-based study that focused on the prevalence of hearing loss among 3,753 participants between 1993 and 1995. This article reports the results of several auditory measures from 999 veteran and 590 nonveteran males 48 to 92 years of age included in the EHLS. The auditory measures included pure tone thresholds, tympanometry and acoustic reflexes, word recognition in quiet and in competing message, and the Hearing Handicap Inventory for the Elderly-Screening (HHIE-S) version. Hearing loss in the auditory domains of pure tone thresholds, word recognition in quiet, and word recognition in competing message increased with age but were not significantly different for the veterans and nonveterans. No significant differences were found between participant groups on the HHIE-S; however, regarding hearing aid usage, mixed differences were found.

Background: This is a case study of an 18-year-old female who suffered a bilateral idiopathic sensorineural hearing loss that was coincident with the removal of four impacted wisdom teeth. Throughout childhood the patient had normal hearing for pure tones bilaterally as measured at the pediatrician's office. One month prior to dental surgery (May) the patient volunteered to participate in an auditory experiment at which time her pure-tone audiogram was normal. Immediately following surgery (June), the patient had substantial swelling of the face and complained of some hearing loss with no other auditory/vestibular complaints. The following month (July) during the course of a routine physical examination a pure-tone audiogram revealed bilateral, air-conduction thresholds of 30‐35 dB HL (500‐4000 Hz) and 20 dB HL (8000 Hz). Because bone conduction was not tested, it is impossible to know whether the hearing loss was conductive, mixed, or sensorineural. The pediatrician thought that the hearing loss was conductive and would resolve as the edema subsided. A month later (August) the subject again volunteered for an auditory experiment at which time her hearing again was tested. Purpose: The purpose of this report is to detail the dental procedures involved in the extraction of the wisdom teeth, to report the results of a variety and series of post-op hearing tests, and to discuss the possible mechanisms that might be involved in the “idiopathic” bilateral sensorineural hearing loss. Research Design: Case report. Results: During the August visit to the laboratory, hearing for pure tones bilaterally was 0 to 5 dB HL at 250‐1000 Hz with a 40‐45 dB HL notch at 2000 Hz with a return to 10 dB HL at 8000 Hz. Air conduction and bone conduction thresholds were equivalent. Word recognition in quiet was ≥92 percent correct for both ears, whereas the signal-to-noise ratio (SNR) hearing loss measured with the Words-in-Noise test was high normal in the left ear with a mild SNR hearing loss in the right ear. Tympanometry and acoustic reflex thresholds were normal. Distortion product otoacoustic emissions were reduced in the 1000‐3000 Hz region for both ears, which is consistent with cochlear hearing loss. The hearing loss has remained unchanged for the past 19 months. Conclusions: The possible etiologies, including insults to the cochleae by vibration trauma and through alterations in the blood supply to the cochleae, are considered.