Clinical Assessment of Functional Hearing Deficits: Speech-in-Noise Performance.

OBJECTIVE: The clinical evaluation of hearing loss, using a pure-tone audiogram, is not adequate to assess the functional hearing capabilities (or handicap) of a patient, especially the speech-in-noise communication difficulties. The primary objective of this study was to measure the effect of elevated hearing thresholds on the recognition performance in various functional speech-in-noise tests that cover acoustic scenes of different complexities and to identify the subset of tests that (a) were sensitive to individual differences in hearing thresholds and (b) provide complementary information to the audiogram. A secondary goal was to compare the performance on this test battery with the self-assessed performance level of functional hearing abilities. DESIGN: In this study, speech-in-noise performance of normal-hearing listeners and listeners with hearing loss (audiometric configuration ranging from near-normal hearing to moderate-severe hearing loss) was measured on a battery of 12 different tests designed to evaluate speech recognition in a variety of speech and masker conditions, and listening tasks. The listening conditions were designed to measure the ability to localize and monitor multiple speakers or to take advantage of masker modulation, spatial separation between the target and the masker, and a restricted vocabulary. RESULTS: Listeners with hearing loss had significantly worse performance than the normal-hearing control group when speech was presented in the presence of a multitalker babble or in the presence of a single competing talker. In particular, the ability to take advantage of modulation benefit and spatial release from masking was significantly affected even with a mild audiometric loss. Elevated thresholds did not have a significant effect on the performance in the spatial awareness task. A composite score of all 12 tests was considered as a global metric of the overall speech-in-noise performance. Perceived hearing difficulties of subjects were better correlated with the composite score than with the performance on a standardized clinical speech-in-noise test. Regression analysis showed that scores from a subset of these tests, which could potentially take less than 10 min to administer, when combined with the better-ear pure-tone average and the subject's age, accounted for as much as 93.2% of the variance in the composite score. CONCLUSIONS: A test that measures speech recognition in the presence of a spatially separated competing talker would be useful in measuring suprathreshold speech-in-noise deficits that cannot be readily predicted from standard audiometric evaluation. Including such a test can likely reduce the gap between patient complaints and their clinical evaluation.

Children's Recognition of Emotional Prosody in Spectrally Degraded Speech Is Predicted by Their Age and Cognitive Status.

OBJECTIVES: It is known that school-aged children with cochlear implants show deficits in voice emotion recognition relative to normal-hearing peers. Little, however, is known about normal-hearing children's processing of emotional cues in cochlear implant-simulated, spectrally degraded speech. The objective of this study was to investigate school-aged, normal-hearing children's recognition of voice emotion, and the degree to which their performance could be predicted by their age, vocabulary, and cognitive factors such as nonverbal intelligence and executive function. DESIGN: Normal-hearing children (6-19 years old) and young adults were tested on a voice emotion recognition task under three different conditions of spectral degradation using cochlear implant simulations (full-spectrum, 16-channel, and 8-channel noise-vocoded speech). Measures of vocabulary, nonverbal intelligence, and executive function were obtained as well. RESULTS: Adults outperformed children on all tasks, and a strong developmental effect was observed. The children's age, the degree of spectral resolution, and nonverbal intelligence were predictors of performance, but vocabulary and executive functions were not, and no interactions were observed between age and spectral resolution. CONCLUSIONS: These results indicate that cognitive function and age play important roles in children's ability to process emotional prosody in spectrally degraded speech. The lack of an interaction between the degree of spectral resolution and children's age further suggests that younger and older children may benefit similarly from improvements in spectral resolution. The findings imply that younger and older children with cochlear implants may benefit similarly from technical advances that improve spectral resolution.

Recognition of time-compressed speech does not predict recognition of natural fast-rate speech by older listeners.

This study investigated whether recognition of time-compressed speech predicts recognition of natural fast-rate speech, and whether this relationship is influenced by listener age. High and low context sentences were presented to younger and older normal-hearing adults at a normal speech rate, naturally fast speech rate, and fast rate implemented by time compressing the normal-rate sentences. Recognition of time-compressed sentences over-estimated recognition of natural fast sentences for both groups, especially for older listeners. The findings suggest that older listeners are at a much greater disadvantage when listening to natural fast speech than would be predicted by recognition performance for time-compressed speech.

Consonant Perception in Connected Syllables Spoken at a Conversational Syllabic Rate.

Closed-set consonant identification, measured using nonsense syllables, has been commonly used to investigate the encoding of speech cues in the human auditory system. Such tasks also evaluate the robustness of speech cues to masking from background noise and their impact on auditory-visual speech integration. However, extending the results of these studies to everyday speech communication has been a major challenge due to acoustic, phonological, lexical, contextual, and visual speech cue differences between consonants in isolated syllables and in conversational speech. In an attempt to isolate and address some of these differences, recognition of consonants spoken in multisyllabic nonsense phrases (e.g., aBaSHaGa spoken as /ɑbɑʃɑɡɑ/) produced at an approximately conversational syllabic rate was measured and compared with consonant recognition using Vowel-Consonant-Vowel bisyllables spoken in isolation. After accounting for differences in stimulus audibility using the Speech Intelligibility Index, consonants spoken in sequence at a conversational syllabic rate were found to be more difficult to recognize than those produced in isolated bisyllables. Specifically, place- and manner-of-articulation information was transmitted better in isolated nonsense syllables than for multisyllabic phrases. The contribution of visual speech cues to place-of-articulation information was also lower for consonants spoken in sequence at a conversational syllabic rate. These data imply that auditory-visual benefit based on models of feature complementarity from isolated syllable productions may over-estimate real-world benefit of integrating auditory and visual speech cues.

Normative Ranges for, and Interrater Reliability of, Rotational Vestibular and Balance Tests in U.S. Military Service Members and Veterans.

PURPOSE: The objectives of this study were to (a) describe normative ranges-expressed as reference intervals (RIs)-for vestibular and balance function tests in a cohort of Service Members and Veterans (SMVs) and (b) to describe the interrater reliability of these tests. METHOD: As part of the Defense and Veterans Brain Injury Center (DVBIC)/Traumatic Brain Injury Center of Excellence 15-year Longitudinal Traumatic Brain Injury (TBI) Study, participants completed the following: vestibulo-ocular reflex suppression, visual-vestibular enhancement, subjective visual vertical, subjective visual horizontal, sinusoidal harmonic acceleration, the computerized rotational head impulse test (crHIT), and the sensory organization test. RIs were calculated using nonparametric methods and interrater reliability was assessed using intraclass correlation coefficients between three audiologists who independently reviewed and cleaned the data. RESULTS: Reference populations for each outcome measure comprised 40 to 72 individuals, 19 to 61 years of age, who served either as noninjured controls (NIC) or injured controls (IC) in the 15-year study; none had a history of TBI or blast exposure. A subset of 15 SMVs from the NIC, IC, and TBI groups were included in the interrater reliability calculations. RIs are reported for 27 outcome measures from the seven rotational vestibular and balance tests. Interrater reliability was considered excellent for all tests except the crHIT, which was found to have good interrater reliability. CONCLUSION: This study provides clinicians and scientists with important information regarding normative ranges and interrater reliability for rotational vestibular and balance tests in SMVs.

Sensitivity of school-aged children to pitch-related cues.

Two experiments investigated the ability of 17 school-aged children to process purely temporal and spectro-temporal cues that signal changes in pitch. Percentage correct was measured for the discrimination of sinusoidal amplitude modulation rate (AMR) of broadband noise in experiment 1 and for the discrimination of fundamental frequency (F0) of broadband sine-phase harmonic complexes in experiment 2. The reference AMR was 100 Hz as was the reference F0. A child-friendly interface helped listeners to remain attentive to the task. Data were fitted using a maximum-likelihood technique that extracted threshold, slope, and lapse rate. All thresholds were subsequently standardized to a common d' value equal to 0.77. There were relatively large individual differences across listeners: eight had relatively adult-like thresholds in both tasks and nine had higher thresholds. However, these individual differences did not vary systematically with age, over the span of 6-16 yr. Thresholds were correlated across the two tasks and were about nine times finer for F0 discrimination than for AMR discrimination as has been previously observed in adults.

Voice emotion recognition by cochlear-implanted children and their normally-hearing peers.

Despite their remarkable success in bringing spoken language to hearing impaired listeners, the signal transmitted through cochlear implants (CIs) remains impoverished in spectro-temporal fine structure. As a consequence, pitch-dominant information such as voice emotion, is diminished. For young children, the ability to correctly identify the mood/intent of the speaker (which may not always be visible in their facial expression) is an important aspect of social and linguistic development. Previous work in the field has shown that children with cochlear implants (cCI) have significant deficits in voice emotion recognition relative to their normally hearing peers (cNH). Here, we report on voice emotion recognition by a cohort of 36 school-aged cCI. Additionally, we provide for the first time, a comparison of their performance to that of cNH and NH adults (aNH) listening to CI simulations of the same stimuli. We also provide comparisons to the performance of adult listeners with CIs (aCI), most of whom learned language primarily through normal acoustic hearing. Results indicate that, despite strong variability, on average, cCI perform similarly to their adult counterparts; that both groups' mean performance is similar to aNHs' performance with 8-channel noise-vocoded speech; that cNH achieve excellent scores in voice emotion recognition with full-spectrum speech, but on average, show significantly poorer scores than aNH with 8-channel noise-vocoded speech. A strong developmental effect was observed in the cNH with noise-vocoded speech in this task. These results point to the considerable benefit obtained by cochlear-implanted children from their devices, but also underscore the need for further research and development in this important and neglected area. This article is part of a Special Issue entitled .