Background Auditory complaints following mild traumatic brain injury are common, but few studies have addressed the role of auditory temporal processing in speech recognition complaints. Purpose In this study, deficits understanding speech in a background of speech noise following MTBI were evaluated with the goal of comparing the relative contributions of auditory and non-auditory factors. Research Design A matched-groups design was used in which a group of listeners with a history of MTBI were compared to a group matched in age and pure-tone thresholds, as well as a control group of young listeners with normal hearing. Study Sample Thirty-three listeners participated in the study, including thirteen in the MTBI group (mean age 46.7 years), eleven in the Matched group (mean age 49 years), and nine in the YNH group (mean age 20.8 years). Data Collection and Analysis Speech-in-noise deficits were evaluated using subjective measures as well as monaural word (WIN) and sentence (QuickSIN) tasks, and a binaural spatial release task. Performance on these measures was compared to psychophysical tasks evaluating monaural and binaural temporal fine structure tasks and spectral resolution. Cognitive measures of attention, processing speed, and working memory were evaluated as a possible difference between MTBI and Matched groups contributing to speech-in-noise deficits. Results A high proportion of listeners in the MTBI group reported difficulty understanding speech in noise (84%) compared to the Matched group (9.1%), and listeners who reported difficulty were more likely to have abnormal results on objective measures of speech in noise. No significant group differences were found between the MTBI and Matched listeners on any of the measures reported, but the number of abnormal tests differed across groups. Regression analysis revealed that a combination of auditory and auditory processing factors contributed to monaural speech-in-noise scores, but the benefit of spatial separation was related to a combination of working memory and peripheral auditory factors across all listeners in the study. Conclusions The results of this study are consistent with previous findings that a subset of listeners with MTBI have objective auditory deficits. Speech-in-noise performance was related to a combination of auditory and non-auditory factors, confirming the important role of audiology in MTBI rehabilitation. Further research is needed to evaluate the prevalence and causal relationship of auditory deficits following MTBI.

This study aims to determine the degree to which Portable Automated Rapid Testing (PART), a freely available program running on a tablet computer, is capable of reproducing standard laboratory results. Undergraduate students were assigned to one of three within-subject conditions that examined repeatability of performance on a battery of psychoacoustical tests of temporal fine structure processing, spectro-temporal amplitude modulation, and targets in competition. The repeatability condition examined test/retest with the same system, the headphones condition examined the effects of varying headphones (passive and active noise-attenuating), and the noise condition examined repeatability in the presence of recorded cafeteria noise. In general, performance on the test battery showed high repeatability, even across manipulated conditions, and was similar to that reported in the literature. These data serve as validation that suprathreshold psychoacoustical tests can be made accessible to run on consumer-grade hardware and perform in less controlled settings. This dataset also provides a distribution of thresholds that can be used as a normative baseline against which auditory dysfunction can be identified in future work.

The current state of consumer-grade electronics means that researchers, clinicians, students, and members of the general public across the globe can create high-quality auditory stimuli using tablet computers, built-in sound hardware, and calibrated consumer-grade headphones. Our laboratories have created a free application that supports this work: PART (Portable Automated Rapid Testing). PART has implemented a range of psychoacoustical tasks including: spatial release from speech-on-speech masking, binaural sensitivity, gap discrimination, temporal modulation, spectral modulation, and spectrotemporal modulation (STM). Here, data from the spatial release and STM tasks are presented. Data were collected across the globe on tablet computers using applications available for free download, built-in sound hardware, and calibrated consumer-grade headphones. Spatial release results were as good or better than those obtained with standard laboratory methods. Spectrotemporal modulation thresholds were obtained rapidly and, for younger normal hearing listeners, were also as good or better than those in the literature. For older hearing impaired listeners, rapid testing resulted in similar thresholds to those reported in the literature. Listeners at five different testing sites produced very similar STM thresholds, despite a variety of testing conditions and calibration routines. Download Spatial Release, PART, and Listen: An Auditory Training Experience for free at https://bgc.ucr.edu/games/.

Purpose Growing evidence supports the inclusion of perceptual tests that quantify the processing of temporal fine structure (TFS) in clinical hearing assessment. Many tasks have been used to evaluate TFS in the laboratory that vary greatly in the stimuli used and whether the judgments require monaural or binaural comparisons of TFS. The purpose of this study was to compare laboratory measures of TFS for inclusion in a battery of suprathreshold auditory tests. A subset of available TFS tasks were selected on the basis of potential clinical utility and were evaluated using metrics that focus on characteristics important for clinical use. Method TFS measures were implemented in replication of studies that demonstrated clinical utility. Monaural, diotic, and dichotic measures were evaluated in 11 young listeners with normal hearing. Measures included frequency modulation (FM) tasks, harmonic frequency shift detection, interaural phase difference (TFS–low frequency), interaural time difference (ITD), monaural gap duration discrimination, and tone detection in noise with and without a difference in interaural phase (N 0 S 0 , N 0 S π ). Data were compared with published results and evaluated with metrics of consistency and efficiency. Results Thresholds obtained were consistent with published data. There was no evidence of predictive relationships among the measures consistent with a homogenous group. The most stable tasks across repeated testing were TFS–low frequency, diotic and dichotic FM, and N 0 S π . Monaural and diotic FM had the lowest normalized variance and were the most efficient accounting for differences in total test duration, followed by ITD. Conclusions Despite a long stimulus duration, FM tasks dominated comparisons of consistency and efficiency. Small differences separated the dichotic tasks FM, ITD, and N 0 S π . Future comparisons following procedural optimization of the tasks will evaluate clinical efficiency in populations with impairment.

Background Amplitude compression is a common hearing aid processing strategy that can improve speech audibility and loudness comfort but also has the potential to alter important cues carried by the speech envelope. In our previous work, a measure of envelope change, the Envelope Difference Index (EDI; Fortune, Woodruff & Preves, 1994) was moderately related to recognition of spectrally-robust consonants. This follow-up study investigated the relationship between the EDI and recognition of spectrally-sparse consonants. Method Stimuli were vowel-consonant-vowel tokens processed to reduce spectral cues. Compression parameters were chosen to achieve a range of EDI values. Recognition was measured for 20 listeners with normal hearing. Results Both overall recognition and perception of consonant features were reduced at higher EDI values. Similar effects were noted with noise-vocoded and sine-vocoded processing, and whether or not periodicity cues were available. Conclusion The data provide information about the acceptable limits of envelope distortion under constrained conditions. These limits can be applied to consider the impact of envelope distortions in situations where other cues are available to varying extents.