Christina M. Roup

Perceptual training improves syllable identification in new and experienced hearing aid users

We assessed the effects of perceptual training of syllable identification in noise on nonsense syllable test (NST) performance of new (Experiment 1) and experienced (Experiment 2) hearing aid (HA) users with sensorineural hearing loss. In Experiment 1, new HA users were randomly assigned to either immediate training (IT) or delayed training (DT) groups. IT subjects underwent 8 weeks of at-home syllable identification training and in-laboratory testing, whereas DT subjects underwent identical in-laboratory testing without training. Training produced large improvements in syllable identification in IT subjects, whereas spontaneous improvement was minimal in DT subjects. DT subjects then underwent training and showed performance improvements comparable with those of the IT group. Training-related improvement in NST scores significantly exceeded improvements due to amplification. In Experiment 2, experienced HA users received identical training and testing procedures as users in Experiment 1. The experienced users also showed significant training benefit. Training-related improvements generalized to untrained voices and were maintained on retention tests. Perceptual training appears to be a promising tool for improving speech perception in new and experienced HA users.

Normal and Hearing-Impaired Word Recognition Scores for Monosyllabic Words in Quiet and Noise

The effects of noise on word recognition scores were assessed with normal-hearing and hearing-impaired subjects. Fifty-one normal-hearing subjects were tested at 50 dB HL using signal-to-noise ratios (S/Ns) of 5, 10, and 15 dB. Thirty subjects with mild-to-moderate sensorineural hearing losses were tested in quiet and in noise at S/Ns of 10 dB and 15 dB. Monosyllabic words in a Multitalker Noise were selected for testing. Mean scores for the normal-hearing subjects were 45% at the 5 dB S/N, 74% at the 10 dB S/N, and 87% at the 15 dB S/N. For the hearing-impaired subjects, scores were 85% in quiet, 60% at the 15 dB S/N, and 40% at the 10 dB S/N. These results suggest that background noise which is mildly disruptive for normal hearing subjects can be highly disruptive to hearing-impaired subjects. Moreover, these findings indicate that subjects with mild-to-moderate sensorineural hearing loss require a more favourable S/N than normal listeners to achieve comparable word recognition scores. Test-retest differences for word recognition scores revealed variability that agreed closely with predictions based on the binomial distribution for both groups of subjects. Speech-in-noise abilities must be measured directly because regression equations revealed that speech-in-noise scores cannot be predicted accurately from either puretone thresholds or speech-in-quiet scores. Word recognition functions are presented from several hearing-impaired subjects and demonstrate the value of testing in noise.

Acclimatization in wide dynamic range multichannel compression and linear amplification hearing aids

Acclimatization was studied in hearing-impaired patients with no previous hearing aid (HA) experience who were fit bilaterally with either wide dynamic range multichannel compression (WDRMCC) or linear amplification (LA) HAs. Throughout 40 weeks of normal HA use, we monitored changes in nonsense syllable perception in speech-spectrum noise. Syllable recognition for WDRMCC users improved by 4.6% over the first 8 weeks, but the 2.2% improvement for LA users was complete in 2 to 4 weeks. Consonant confusion analyses indicated that WDRMCC experience facilitated consonant identification, while LA users primarily changed their response biases. Furthermore, WDRMCC users showed greater improvement for aided than unaided stimuli, while LA users did not. These results demonstrate acclimatization in new users of WDRMCC HAs but not in new users of LA HAs. A switch in amplification type after 32 weeks produced minimal performance change. Thus, acclimatization depended on the type of amplification and the previous amplification experience.

Behavioral and electrophysiologic binaural processing in persons with symmetric hearing loss.

BACKGROUND Binaural hearing improves our ability to understand speech and to localize sounds. Hearing loss can interfere with binaural cues, and despite the success of amplification, ∼25% of people with bilateral hearing loss fit with two hearing aids choose to wear only one (e.g., Brooks and Bulmer, 1981). One explanation is reduced binaural processing, which occurs when the signal presented to one ear interferes with the perception of the signal presented to the other ear (e.g., Jerger et al, 1993). Typical clinical measures, however, are insensitive to binaural processing deficits. PURPOSE The purpose of this study was to determine the extent to which behavioral measures of binaural performance were related to electrophysiological measures of binaural processing in subjects with symmetrical pure-tone sensitivity. RESEARCH DESIGN The relationship between middle latency responses (MLRs) and behavioral performance on binaural listening tasks was assessed by Spearmans rho correlation analyses. Separate repeated measures analyses of variance (RMANOVAs) were performed for MLR latency and MLR amplitude. STUDY SAMPLE Nineteen subjects were recruited for the present study based on a clinical presentation of symmetrical pure-tone sensitivity with asymmetrical performance on a word-recognition in noise test. This subpopulation of patients included both subjects with and subjects without hearing loss. DATA COLLECTION AND ANALYSIS Monaural and binaural auditory processing was measured behaviorally and electrophysiologically in right-handed subjects. The behavioral tests included the Words-in-Noise test (WIN), the dichotic digits test (DDT), and the 500 Hz masking level difference (MLD). Electrophysiologic responses were measured by the binaural interaction component (BIC) of the MLR. The electrophysiological responses were analyzed to examine the effects of peak (Na, Pa, and Nb) and condition (monaural left, monaural right, binaural, and BIC) on MLR amplitude and latency. RESULTS Significant correlations were found among electrophysiological measures of binaural hearing and behavioral tests of binaural hearing. A strong correlation between the MLD and the binaural Na-Pa amplitude was found (r = .816). CONCLUSIONS The behavioral and electrophysiological measures used in the present study clearly showed evidence of reduced binaural processing in ∼10 of the subjects in the present study who had symmetrical pure-tone sensitivity. These results underscore the importance of understanding binaural auditory processing and how these measures may or may not identify functional auditory problems.

Dichotic Speech Recognition Using CVC Word and Nonsense CVC Syllable Stimuli

BACKGROUND The effects of stimulus material, lexical content, and response condition on dichotic speech recognition performance characteristics were examined for normal-hearing young adult listeners. No previous investigation has systematically examined the effects of stimulus material with constant phonetic content but varied lexical content across three response conditions typically used to evaluate binaural auditory processing abilities. PURPOSE To examine how dichotic speech recognition performance varies for stimulus materials with constant phonetic content but varied lexical content across the free recall, directed recall right, and directed recall left response conditions. RESEARCH DESIGN Dichotic speech recognition was evaluated using consonant-vowel-consonant (CVC) word and nonsense CVC syllable stimuli administered in the free recall, directed right, and directed left response conditions, a repeated measures experimental design. STUDY SAMPLE Thirty normal-hearing young adults (15 male, 15 female) served as participants. Participants ranged in age from 18 to 31 yr and were all right-handed. DATA COLLECTION AND ANALYSIS Participants engaged in monaural speech recognition and dichotic speech recognition tasks. Percent correct recognition per ear, as well as ear advantage for dichotic speech recognition, were calculated and evaluated using a repeated measures analysis of variance (ANOVA) statistical procedure. RESULTS Dichotic speech recognition performance for nonsense CVC syllables was significantly poorer than performance for CVC words, suggesting that lexical content impacts performance on dichotic speech recognition tasks. Performance also varied across response condition, which is consistent with previous studies of dichotic speech recognition. CONCLUSIONS Lexical content of stimulus materials impacts performance characteristics for dichotic speech recognition tasks in the normal-hearing young adult population. The use of nonsense CVC syllable material may provide a way to assess dichotic speech recognition performance while potentially lessening the effects of lexical content on performance.

Effect of dichotic listening on self-reported state anxiety.

Abstract The present study examined the relationship between dichotic speech recognition and state anxiety. State anxiety, as determined by the State-Trait anxiety inventory (STAI), was measured pre- and post-dichotic testing in a group of young adults with normal hearing. Dichotic speech recognition was measured for three types of speech stimuli: 3-pair digits, monosyllabic words, and consonant-vowels. Results revealed significant increases in state anxiety as a function of dichotic testing for all stimulus types. There was not a significant difference, however, in state anxiety between the stimulus types. A subset of subjects (n=44) repeated the experiment a second time. There were no significant differences in state anxiety experienced due to dichotic listening between the two sessions. Results from the present study confirm that dichotic listening induces significant increases in state anxiety in a group of young adults with normal hearing. Although statistically significant, the mean increase in state anxiety does not exceed normative levels for college students. Further, the effect of anxiety on dichotic speech recognition performance appears minimal in this population. Sumario El presente estudio examinó la relación entre el reconocimiento dicótico del lenguaje y los estados de ansiedad. El estado de ansiedad, determinado por el inventario estatal de rasgos de ansiedad (STAI), fue medido antes y después de las pruebas dicóticas en un grupo de adultos jóvenes con audición normal. El reconocimiento dicótico del lenguaje fue medido con tres tipos de estímulos lingüísticos: dígitos en 3 pares, monosilábicos dicóticos, y vocalesconsonantes. Los resultados revelaron aumentos significativos en el estado de ansiedad como una función de la evaluación dicóticos para todos los tipos de estímulos. No existió una diferencia significativa , sin embargo, en el estado de ansiedad entre los tipos de estímulos. Un subgrupo de sujetos (n = 44) repitió el experimento una segunda vez. No hubo diferencias significativas en el estado de ansiedad experimentado debido a la audición dicótica entre las dos sesiones. Los resultados del presente estudio confirman que la audición dicótica induce aumentos significativos en el estado de ansiedad en un grupo de adultos jóvenes con audición normal. Aunque resulte estadísticamente significativo, la media del incremento en el estado de ansiedad no excede los valores normativos para estudiantes universitarios. Más aún, el efecto de la ansiedad sobre el desempeño en el reconocimiento dicótico del lenguaje parece mínimo en esta población.

Masking of low-frequency signals by high-frequency, high-level narrow bands of noise.

Low-frequency masking by intense high-frequency noise bands, referred to as remote masking (RM), was the first evidence to challenge energy-detection models of signal detection. Its underlying mechanisms remain unknown. RM was measured in five normal-hearing young-adults at 250, 350, 500, and 700 Hz using equal-power, spectrally matched random-phase noise (RPN) and low-noise noise (LNN) narrowband maskers. RM was also measured using equal-power, two-tone complex (TC2) and eight-tone complex (TC8). Maskers were centered at 3000 Hz with one or two equivalent rectangular bandwidths (ERBs). Masker levels varied from 80 to 95 dB sound pressure level in 5 dB steps. LNN produced negligible masking for all conditions. An increase in bandwidth in RPN yielded greater masking over a wider frequency region. Masking for TC2 was limited to 350 and 700 Hz for one ERB but shifted to only 700 Hz for two ERBs. A spread of masking to 500 and 700 Hz was observed for TC8 when the bandwidth was increased from one to two ERBs. Results suggest that high-frequency noise bands at high levels could generate significant low-frequency masking. It is possible that listeners experience significant RM due to the amplification of various competing noises that might have significant implications for speech perception in noise.

How does aging affect recognition of spectrally degraded speech?: Aging and Recognition of Degraded Speech

Cochlear implants (CIs) restore auditory sensation to patients with moderate‐to‐profound sensorineural hearing loss. However, the benefits to speech recognition vary considerably among patients. Advancing age contributes to this variability in postlingual adult CI users. Similarly, older individuals with normal hearing (NH) perform more poorly on tasks of recognition of spectrally degraded speech. The overarching hypothesis of this study was that the detrimental effects of advancing age on speech recognition can be attributed both to declines in auditory spectral resolution as well as declines in cognitive functions.

Sensitivity of pure tone versus speech-in-noise hearing screening

Adults classified as having normal hearing using conventional pure tone hearing screening often report hearing difficulties especially for situations requiring listening for speech or music in a background of noise. The purpose of this project is to compare the sensitivity of a pure tone hearing screener with a Spoken Digits in Noise test. In the first comparison, 20 young adults with normal hearing thresholds documented by a full audiometric test were asked to simulate a conductive hearing loss using an ear plug inserted into one ear. Both screeners were used to detect the simulated conductive hearing loss. In the second comparison, participants with documented mild to moderate sensorineural hearing loss were tested with both screeners. Order of testing with the screeners was counter-balanced, and the degree of hearing loss was categorized into 15 dB intervals based on their three-frequency (500, 1000, and 2000 Hz) averages and labeled Normal, Slight, Mild, or Moderate. A decision theory analysis was use...

Mild-Gain Hearing Aids as a Treatment for Adults with Self-Reported Hearing Difficulties

BACKGROUND There is a growing body of evidence demonstrating self-reported hearing difficulties (HD; i.e., substantial difficulty in understanding speech in complex listening situations) in adults with normal pure-tone sensitivity. Anecdotally, some audiologists have tried personal mild-gain amplification as a treatment option for adults with HD. In 2008, Kuk and colleagues reported positive results of a mild-gain hearing aid trial for children with auditory processing disorders. To date, however, there have been no studies investigating the benefit of mild-gain amplification to treat HD in adults with normal audiograms. PURPOSE The effectiveness of a four-week trial with mild-gain amplification for adults with self-reported HD and clinically normal hearing sensitivity was investigated. RESEARCH DESIGN Two participant groups with normal pure-tone audiograms (thresholds ≤20 dB HL 250-8000 Hz) were recruited to study the effects of self-reported HD on hearing handicap, self-perceived auditory processing difficulties, and performance on a speech-in-noise task. Furthermore, the benefit of mild-gain amplification was examined after a four-week hearing aid trial on self-perceived hearing handicap and auditory processing difficulties, and performance on an aided speech-in-noise task. Effects were analyzed using a mixed-model repeated measures analysis of variance. Posthoc analyses were performed for each significant main effect. STUDY SAMPLE Thirty-nine participants participated in two groups. Twenty normal hearing adults (19-27 yr) without complaints of HD were recruited as a control group. Nineteen normal hearing adults (18-58 yr) with self-reported HD were recruited for the mild-gain hearing aid trial. DATA COLLECTION AND ANALYSIS Subjective complaints of HD were assessed with two questionnaires (the Hearing Handicap Inventory for Adults [HHIA] and the Auditory Processing Questionnaire [APQ]) and an auditory processing test battery (SCAN:3-A, dichotic digit recognition, gaps-in-noise test, and the 500-Hz masking level difference). Speech-in-noise abilities were assessed before and after hearing aid trial using the Revised Speech Perception in Noise Test (R-SPIN) at multiple signal-to-noise ratios. Hearing aid use and impressions during the hearing aid trial were recorded. RESULTS Results demonstrated that participants with HD perceived significantly greater hearing handicap (HHIA) and greater self-perceived auditory processing difficulties (APQ) than the control group. Participants with HD performed significantly poorer on the R-SPIN relative to controls, especially for low-predictability items. Results of the hearing aid trial for participants with HD revealed significant improvements in hearing handicap, self-perceived auditory processing difficulties, and speech-in-noise performance relative to prehearing aid trial measures. The hearing aids were well tolerated by the majority of participants with HD , with most of them wearing the hearing aids an average of 1-4 h per day. CONCLUSIONS The results from the present study suggest that adults who present with complaints of HD even in the presence of normal hearing sensitivity represent a unique population that warrants further evaluation beyond the standard hearing test. Furthermore, results from the hearing aid trial suggest that mild-gain amplification is a viable treatment option for at least some individuals with HD.