Auditory perceptions induced by low-frequency acoustic and electric stimulation

Area of Science:

• Auditory Neuroscience
• Psychoacoustics
• Electrophysiology

Background:

• Understanding low-frequency (LF) auditory perception is crucial for both normal-hearing individuals and those with hearing impairments.
• Investigating the mechanisms underlying LF perception, particularly the role of neural synchrony, remains an active area of research.
• Previous studies have explored LF acoustic perception, but direct comparisons with electric stimulation are less common.

Purpose of the Study:

• To compare listener perceptions of LF acoustic and electric stimuli.
• To investigate the potential role of neural synchrony in LF auditory perception.
• To examine differences in perception between pulsatile and sinusoidal stimuli at LF.

Main Methods:

• A single normal-hearing participant and three profoundly deaf participants with intracochlear electrode systems were involved.
• Participants described auditory perceptions to pulsatile and sinusoidal stimuli ranging from 5 to 60 cycles per second (c/s).
• Stimuli were delivered acoustically and electrically via intracochlear electrodes.

Main Results:

• LF acoustic and electric stimuli elicited similar auditory perceptions.
• No tactual component was detected for electric stimuli, unlike reported findings for LF acoustic stimuli.
• Perceptual differences between pulsed and sinusoidal stimuli were observed at 5 c/s, linked to neural synchrony.

Conclusions:

• LF auditory perception, for both acoustic and electric stimuli, appears to be mediated by similar mechanisms.
• The findings provide direct support for the neural volley mechanism theory of LF auditory perception in normal-hearing listeners.
• Differences at very low frequencies (5 c/s) highlight the importance of stimulus waveform and neural synchrony in LF hearing.