Auditory Biases in Cognitive Assessment: Insights from a Hearing-Loss Simulation for the Screening of Dementia due to Alzheimer's Disease

Cognitive-screening tests are used to detect pathological changes in mental abilities. Many use orally presented instructions and test items. Hence, hearing loss (HL), whose prevalence increases with age, may bias cognitive-test performance in the target population for the screening of dementia due to Alzheimer's disease. To study the effect of the auditory test format, an impairment-simulation approach was used in normal-hearing listeners to compare performance on the Hopkins Verbal Learning Test, a memory task employed in dementia screening and research, when test items were unprocessed and processed to simulate age-related HL. Immediate verbal recall declined with simulated HL, suggesting that auditory factors are confounding variables in cognitive assessment and result in the underestimation of cognitive functioning

On the (un)importance of working memory in speech-in-noise processing for listeners with normal hearing thresholds

With the advent of cognitive hearing science, increased attention has been given to individual differences in cognitive functioning and their explanatory power in accounting for inter-listener variability in the processing of speech in noise (SiN). The psychological construct that has received much interest in recent years is working memory. Empirical evidence indeed confirms the association between WM capacity (WMC) and SiN identification in older hearing-impaired listeners. However, some theoretical models propose that variations in WMC are an important predictor for variations in speech processing abilities in adverse perceptual conditions for all listeners, and this notion has become widely accepted within the field. To assess whether WMC also plays a role when listeners without hearing loss process speech in adverse listening conditions, we surveyed published and unpublished studies in which the Reading-Span test (a widely used measure of WMC) was administered in conjunction with a measure of SiN identification, using sentence material routinely used in audiological and hearing research. A meta-analysis revealed that, for young listeners with audiometrically normal hearing, individual variations in WMC are estimated to account for, on average, less than 2% of the variance in SiN identification scores. This result cautions against the (intuitively appealing) assumption that individual variations in WMC are predictive of SiN identification independently of the age and hearing status of the listener

Modulation masking produced by second-order modulators

Recent studies suggest that an auditory nonlinearity converts second-order sinusoidal amplitude modulation (SAM) (i.e., modulation of SAM depth) into a first-order SAM component, which contributes to the perception of second-order SAM. However, conversion may also occur in other ways such as cochlear filtering. The present experiments explored the source of the first-order SAM component by investigating the ability to detect a 5-Hz, first-order SAM probe in the presence of a second-order SAM masker beating at the probe frequency. Detection performance was measured as a function of masker-carrier modulation frequency, phase relationship between the probe and masker modulator, and probe modulation depth. In experiment 1, the carrier was a 5-kHz sinusoid presented either alone or within a notched-noise masker in order to restrict off-frequency listening. In experiment 2, the carrier was a white noise. The data obtained in both carrier conditions are consistent with the existence of a modulation distortion component. However, the phase yielding poorest detection performance varied across experimental conditions between 0° and 180°, confirming that, in addition to nonlinear mechanisms, cochlear filtering and off-frequency listening play a role in second-order SAM perception. The estimated magnitude of the modulation distortion component ranges from 5%-12%

Automatic speech recognition predicts speech intelligibility and comprehension for listeners with simulated age-related hearing loss

Purpose: To assess speech processing for listeners with simulated age-related hearing loss (ARHL) and to investigate whether the observed performance can be replicated using an Automatic Speech Recognition (ASR) system. The long-term goal of this research is to develop a system that will assist audiologists/hearing-aid dispensers in the fine-tuning of hearing aids. Method: Sixty young normal-hearing participants listened to speech materials mimicking the perceptual consequences of ARHL at different levels of severity. Two intelligibility tests (repetition of words and sentences) and one comprehension test (responding to oral commands by moving virtual objects) were administered. Several language models were developed and used by the ASR system in order to fit human performances. Results: Strong significant positive correlations were observed between human and ASR scores, with coefficients up to .99. However, the spectral smearing used to simulate losses in frequency selectivity caused larger declines in ASR performance than in human performance. Conclusion: Both intelligibility and comprehension scores for listeners with simulated ARHL are highly correlated with the performances of an ASR-based system. In the future, it needs to be determined if the ASR system is similarly successful in predicting speech processing in noise and by older people with ARHL

Development of a method for determining binaural sensitivity to temporal fine structure.

OBJECTIVE: To develop and evaluate a test of the ability to process binaural temporal-fine-structure (TFS) information. The test was intended to provide a graded measure of TFS sensitivity for all listeners. DESIGN: Sensitivity to TFS was assessed at a sensation level of 30 dB using the established TFS-LF test at centre frequencies of 250, 500 and 750 Hz, and using the new TFS-AF test, in which the interaural phase difference (IPD) was fixed and the frequency was adaptively varied. IPDs varied from 30 to 180°. STUDY SAMPLE: Nine young (19-25 years) and 23 older (47-84 years) listeners with normal hearing over the tested frequency range. RESULTS: For the young listeners, thresholds on the TFS-AF test did not improve significantly with repeated testing. The rank-ordering of performance across listeners was independent of the size of the IPD, and moderate-to-strong correlations were observed between scores for the TFS-LF and TFS-AF tests. Older listeners who were unable to complete the TFS-LF test were all able to complete the TFS-AF test. CONCLUSIONS: No practice effects and strong correlations with an established test of binaural TFS sensitivity make the TFS-AF test a good candidate for the assessment of supra-threshold binaural processing

Does training with amplitude modulated tones affect tone-vocoded speech perception?

Temporal-envelope cues are essential for successful speech perception. We asked here whether training on stimuli containing temporal-envelope cues without speech content can improve the perception of spectrally-degraded (vocoded) speech in which the temporal-envelope (but not the temporal fine structure) is mainly preserved. Two groups of listeners were trained on different amplitude-modulation (AM) based tasks, either AM detection or AM-rate discrimination (21 blocks of 60 trials during two days, 1260 trials; frequency range: 4Hz, 8Hz, and 16Hz), while an additional control group did not undertake any training. Consonant identification in vocoded vowel-consonant-vowel stimuli was tested before and after training on the AM tasks (or at an equivalent time interval for the control group). Following training, only the trained groups showed a significant improvement in the perception of vocoded speech, but the improvement did not significantly differ from that observed for controls. Thus, we do not find convincing evidence that this amount of training with temporal-envelope cues without speech content provide significant benefit for vocoded speech intelligibility. Alternative training regimens using vocoded speech along the linguistic hierarchy should be explored

Technikreflexionen in Fernsehserien

Serielle Medien wollen massenmedial verstärkte Resonanzen erzielen. Sie generieren ein historisch wandelbares Wissen, das sie für die Selbstverständigungen in Kultur und Gesellschaft relevant, d.h. für Kulturdiagnosen geeignet macht. Diese mediale Spezifik wird im vorliegenden Band systematisch wie historisch auf die Frage nach der Popularisierung und Reflexion von Technikwissen und Technikdiskursen hin untersucht. Fernsehserien bieten sich dafür wegen ihrer eigenen Zeitlichkeit an: Sie können sich narrativ komplex entfalten, auch weil in ihrer Plot-Anlage ein Ende nicht notwendig gesetzt wird. Fernsehserien bilden Technik in ihren Folgen dabei nicht nur thematisch ab, vielmehr organisieren technische Mittel ihre Darstellungsformen selbst. In Fallstudien zu einzelnen Serien dokumentiert vorliegender Band Facetten solcher Technikreflexionen. Abschließend stellt er eine Typologie ihrer Formvarianten zur Diskussion

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Predicting real-life listening abilities in presbyacusic adults

It is well known that many hearing-impaired (HI) people are often dissatisfied with the speech intelligibility achieved with their hearing aids (HAs) in everyday life. Assuming that HA fitting is done appropriately, the discrepancy between listening behavior in the laboratory/clinic and that in real-life communication situations must therefore stem from the fact that the tests conducted by the hearing healthcare professional are insufficient and/or of poor ecological validity. Three studies were conducted to shed some light on these hypotheses. An online survey of the current practice of speech audiometry in France was designed. Two hundred and ninety-seven HA dispensers provided information about the type and frequency of use of diagnostic and prognostic tests performed during the audiological assessment of adults, including the most common forms of speech audiometry in terms of speech material and background sounds (Rembaud et al., 2017). Two behavioral studies were conducted on 100 older (aged 60-85 years) HI adults who had worn their HAs for at least six months. In addition to tests of speech audiometry, a measure of sensitivity to binaural temporal-fine structure information (Füllgrabe et al., 2017) and two cognitive tasks, probing working memory and inhibition, were administered. Real-life listening abilities were assessed using the 15iSSQ, covering speech perception, spatial hearing, and qualitative and cognitive aspects of hearing (Moulin et al., 2019). Performances on the different tasks as well as their relationship with the self-report of everyday listening will be discussed in the presentation. Füllgrabe et al. (2017). Development of a method for determining binaural sensitivity to temporal fine structure. Int J Audiol, 56(12), 926-935. Moulin et al. (2019). A new Speech, Spatial, and Qualities of hearing scale short-form: Factor, cluster, and comparative analyses. Ear Hear, 40(4), 938-950. Rembaud et al. (2017). L’audiométrie vocale en France: état des lieux. Cahiers Audition, 6, 22-25