Auditory and visual orienting responses in listeners with and without hearing-impairment

Area of Science:

• Auditory Neuroscience
• Human Motor Control
• Psychoacoustics

Background:

• Head movements are crucial for sound localization.
• These movements may compensate for auditory deficits.

Purpose of the Study:

• To investigate head movement differences between normal-hearing and hearing-impaired individuals during auditory and visual target localization.
• To characterize the impact of hearing impairment on the kinematics of head orienting responses.

Main Methods:

• Infrared camera system to track head position and orientation.
• 17 normal-hearing and 14 hearing-impaired listeners participated.
• Listeners oriented towards visual targets or auditory stimuli from loudspeakers.

Main Results:

• Hearing-impaired listeners showed greater auditory-visual fixation differences and increased latency for auditory targets.
• Peak head movement velocity was similar (~140°/s) in both groups.
• Hearing impairment led to less smooth head movements, with abrupt velocity changes, direction reversals, and more corrections.

Conclusions:

• Hearing impairment significantly affects head movement strategies for sound localization.
• These altered movements reflect compensatory mechanisms or deficits in auditory processing.
• The findings highlight the complex interplay between auditory perception and motor control in hearing-impaired individuals.