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Purpose: Prosody perception is an essential component of speech communication and social interaction through which both linguistic and emotional information are conveyed. Considering the importance of the auditory system in processing prosody-related acoustic features, the aim of this review article is to review the effects of hearing impairment on prosody perception in children and adults. It also assesses the performance of hearing assistive devices in restoring prosodic perception. Method: Following a comprehensive online database search, two lines of inquiry were targeted. The first summarizes recent attempts toward determining the effects of hearing loss and interacting factors such as age and cognitive resources on prosody perception. The second analyzes studies reporting beneficial or detrimental impacts of hearing aids, cochlear implants, and bimodal stimulation on prosodic abilities in people with hearing loss. Results: The reviewed studies indicate that hearing-impaired individuals vary widely in perceiving affective and linguistic prosody, depending on factors such as hearing loss severity, chronological age, and cognitive status. In addition, most of the emerging information points to limitations of hearing assistive devices in processing and transmitting the acoustic features of prosody. Conclusions: The existing literature is incomplete in several respects, including the lack of a consensus on how and to what extent hearing prostheses affect prosody perception, especially the linguistic function of prosody, and a gap in assessing prosody under challenging listening situations such as noise. This review article proposes directions that future research could follow to provide a better understanding of prosody processing in those with hearing impairment, which may help health care professionals and designers of assistive technology to develop innovative diagnostic and rehabilitation tools.

We investigated whether pitch-synchronous neural activity could be recorded in humans, with a natural vowel and a vowel in which the fundamental frequency was suppressed. Small variations of speech periodicity were detected in the evoked responses using a fine structure spectrograph (FSS). A significant response (P [much less than] 0.001) was measured in all seven normal subjects even when the fundamental frequency was suppressed, and it very accurately tracked the acoustic pitch contour (normalized mean absolute error < 0.57%). Small variations in speech periodicity, which humans can detect, are therefore available to the perceptual system as pitch-synchronous neural firing. These findings suggest that the measurement of pitch-evoked responses may be a viable tool for objective speech audiometry. Index Terms--Bioelectric potentials, biomedical signal processing, speech processing, time-frequency analysis.

Researchers have investigated the impact of congestive heart failure (CHF) on the rhythmic control of muscle sympathetic nerve activity (MSNA). This involved characterizing oscillations in MSNA in the frequency domain in health men and men with CHF. These were related to blood pressure (BP), breathing frequency and heart rate (HR). It was possible to identify spectral power in the MSNA signal which is similar in magnitude in people with normal and impaired ventricular functions in relation to total power and the relative proportion of harmonic and nonharmonic elements.

We propose the binaural auditory system as a candidate neural system that may be disrupted by exposure to relatively weak LF magnetic fields. Extracellular currents, induced by time-varying magnetic fields, may change the timing of action potentials in the auditory nerve, thereby disrupting sound localization when interaural time differences are very small. Three subjects were exposed to a 1000 Hz magnetic field--with a maximum rate of change of 2.3 T/s at the location of the cochlea--while presenting two identical 1000 Hz tones randomly delayed to the left or right ear by less than 10 ps. The subjects were asked whether the signal was perceived to be displaced to the left or right side of midline. After a total of over 20,000 trials, conducted at different phase angles between the field signal and the tones, there was no clear evidence for a consistent change in performance when the magnetic field was present. This, however, does not rule out an effect at other combinations of magnetic and acoustic frequencies.

This study introduces an improved method to investigate the effects of reverberation using the speech-evoked auditory brainstem response (ABR) that more realistically captures the influence of self- and overlap-masking induced by room reverberation. Speech-evoked ABR was measured under three acoustic scenarios: anechoic, mild reverberation with dominance of early reflections, and severe reverberation with dominance of late reverberation. Responses were significantly weaker and had longer latencies with severe reverberation relative to anechoic and mild reverberation. Although larger responses and shorter latencies were observed with mild reverberation than anechoic, possibly due to early reflections, these reached significance in only one of six ABR response measures. [ABSTRACT FROM AUTHOR]