Robert H. Pierzycki

Relation between Speech-in-Noise Threshold, Hearing Loss and Cognition from 40–69 Years of Age

Background Healthy hearing depends on sensitive ears and adequate brain processing. Essential aspects of both hearing and cognition decline with advancing age, but it is largely unknown how one influences the other. The current standard measure of hearing, the pure-tone audiogram is not very cognitively demanding and does not predict well the most important yet challenging use of hearing, listening to speech in noisy environments. We analysed data from UK Biobank that asked 40–69 year olds about their hearing, and assessed their ability on tests of speech-in-noise hearing and cognition. Methods and Findings About half a million volunteers were recruited through NHS registers. Respondents completed ‘whole-body’ testing in purpose-designed, community-based test centres across the UK. Objective hearing (spoken digit recognition in noise) and cognitive (reasoning, memory, processing speed) data were analysed using logistic and multiple regression methods. Speech hearing in noise declined exponentially with age for both sexes from about 50 years, differing from previous audiogram data that showed a more linear decline from <40 years for men, and consistently less hearing loss for women. The decline in speech-in-noise hearing was especially dramatic among those with lower cognitive scores. Decreasing cognitive ability and increasing age were both independently associated with decreasing ability to hear speech-in-noise (0.70 and 0.89 dB, respectively) among the population studied. Men subjectively reported up to 60% higher rates of difficulty hearing than women. Workplace noise history associated with difficulty in both subjective hearing and objective speech hearing in noise. Leisure noise history was associated with subjective, but not with objective difficulty hearing. Conclusions Older people have declining cognitive processing ability associated with reduced ability to hear speech in noise, measured by recognition of recorded spoken digits. Subjective reports of hearing difficulty generally show a higher prevalence than objective measures, suggesting that current objective methods could be extended further.

Evaluation of the acoustic coordinated reset (CR ®) neuromodulation therapy for tinnitus: study protocol for a double-blind randomized placebo-controlled trial

BackgroundCurrent theories of tinnitus assume that the phantom sound is generated either through increased spontaneous activity of neurons in the auditory brain, or through pathological temporal firing patterns of the spontaneous neuronal discharge, or a combination of both factors. With this in mind, Tass and colleagues recently tested a number of temporally patterned acoustic stimulation strategies in a proof of concept study. Potential therapeutic sound regimes were derived according to a paradigm assumed to disrupt hypersynchronous neuronal activity, and promote plasticity mechanisms that stabilize a state of asynchronous spontaneous activity. This would correspond to a permanent reduction of tinnitus. The proof of concept study, conducted in Germany, confirmed the safety of the acoustic stimuli for use in tinnitus, and exploratory results indicated modulation of tinnitus-related pathological synchronous activity with potential therapeutic benefit. The most effective stimulation paradigm is now in clinical use as a sound therapy device, the acoustic coordinated reset (CR®) neuromodulation (Adaptive Neuromodulation GmbH (ANM), Köln, Germany).Methods/DesignTo measure the efficacy of CR® neuromodulation, we devised a powered, two-center, randomized controlled trial (RCT) compliant with the reporting standards defined in the Consolidated Standards of Reporting Trials (CONSORT) Statement. The RCT design also addresses the recent call for international standards within the tinnitus community for high-quality clinical trials. The design uses a between-subjects comparison with minimized allocation of participants to treatment and placebo groups. A minimization approach was selected to ensure that the two groups are balanced with respect to age, gender, hearing, and baseline tinnitus severity. The protocol ensures double blinding, with crossover of the placebo group to receive the proprietary intervention after 12 weeks. The primary endpoints are the pre- and post-treatment measures that provide the primary measures of efficacy, namely a validated and sensitive questionnaire measure of the functional impact of tinnitus. The trial is also designed to capture secondary changes in tinnitus handicap, quality (pitch, loudness, bandwidth), and changes in tinnitus-related pathological synchronous brain activity using electroencephalography (EEG).DiscussionThis RCT was designed to provide a confident high-level estimate of the efficacy of sound therapy using CR® neuromodulation compared to a well-matched placebo intervention, and uniquely in terms of sound therapy, examine the physiological effects of the intervention against its putative mechanism of action.Trial registrationClinicalTrials.gov, NCT01541969

Indications for temporal fine structure contribution to co-modulation masking release

The contribution of temporal fine structure (TFS) information to co-modulation masking release (CMR) was examined by comparing CMR obtained with unprocessed or vocoded stimuli. Tone thresholds were measured in the presence of a sinusoidally amplitude-modulated on-frequency band (OFB) of noise and zero, two, or four flanking bands (FBs) of noise whose envelopes were either co- or anti-modulated with the OFB envelope. Vocoding replaced the TFS of the tone and masker with unrelated TFS of noise or sinusoidal carriers. Maximum CMR of 11 dB was found as the difference between the co- and anti-modulated conditions for unprocessed stimuli. After vocoding, tone thresholds increased by 7 dB, and CMR was reduced to about 4 dB but remained significant. The magnitude of CMR was similar for both the sine and the noise vocoder. Co-modulation improved detection in the vocoded condition despite the absence of the tone-masker TFS interactions; thus CMR appears to be a robust mechanism based on across-frequency processing. TFS information appears to contribute to across-channel CMR since the magnitude of CMR was significantly reduced after vocoding. Since CMR was evidenced despite vocoding, it is hoped that co-modulation would also improve detection in cochlear-implant listening.

Tinnitus and Sleep Difficulties After Cochlear Implantation.

Objectives: To estimate and compare the prevalence of and associations between tinnitus and sleep difficulties in a sample of UK adult cochlear implant users and those identified as potential candidates for cochlear implantation. Design: The study was conducted using the UK Biobank resource, a population-based cohort of 40- to 69-year olds. Self-report data on hearing, tinnitus, sleep difficulties, and demographic variables were collected from cochlear implant users (n = 194) and individuals identified as potential candidates for cochlear implantation (n = 211). These “candidates” were selected based on (i) impaired hearing sensitivity, inferred from self-reported hearing aid use and (ii) impaired hearing function, inferred from an inability to report words accurately at negative signal to noise ratios on an unaided closed-set test of speech perception. Data on tinnitus (presence, persistence, and related distress) and on sleep difficulties were analyzed using logistic regression models controlling for gender, age, deprivation, and neuroticism. Results: The prevalence of tinnitus was similar among implant users (50%) and candidates (52%; p = 0.39). However, implant users were less likely to report that their tinnitus was distressing at its worst (41%) compared with candidates (63%; p = 0.02). The logistic regression model suggested that this difference between the two groups could be explained by the fact that tinnitus was less persistent in implant users (46%) compared with candidates (72%; p < 0.001). Self-reported difficulties with sleep were similar among implant users (75%) and candidates (82%; p = 0.28), but participants with tinnitus were more likely to report sleep difficulties than those without (p < 0.001). The prevalence of sleep difficulties was not related to tinnitus persistence (p = 0.28) or the extent to which tinnitus was distressing (p = 0.55). Conclusions: The lack of association between tinnitus persistence and sleep difficulties is compatible with the notion that tinnitus is suppressed in implant users primarily during active electrical stimulation and may return when the implant is switched off at night time. This explanation is supported by the similar prevalence of sleep problems among implant users and potential candidates for cochlear implantation, despite differences between the groups in tinnitus persistence and related emotional distress. Cochlear implantation may therefore not be an appropriate intervention where the primary aim is to alleviate sleep difficulties.

Comodulation masking release with signal‐masker interactions represented in the envelope.

In normal hearing, the threshold of a tone masked by a modulated narrow‐band on‐frequency masker (OFB) can be reduced if correlated modulation is present on spectrally distant flanking bands (FBs), an effect known as comodulation masking release (CMR). Since electric hearing with current cochlear implants is based on envelope information, comodulation of envelopes on multiple electrodes might also be beneficial for detection in electric hearing. CMR was investigated with normal‐hearing participants listening to unprocessed or vocoded stimuli. In Experiment 1, tone thresholds were determined when masked by a sinusoidally amplitude‐modulated band of noise (SAM and OFB) and by zero to four FBs of noise whose envelopes were either co‐ or anti‐modulated with the OFB envelope. In Experiment 2, envelopes of those signals were extracted in a vocoder and used to modulate noise or sinusoidal carriers, thereby replacing the original temporal fine structure (TFS). Significant CMR of 3–10 dB was found in unprocessed c...