Localization in speech mixtures by listeners with hearing loss

Area of Science:

• Auditory Neuroscience
• Speech Perception
• Psychoacoustics

Background:

• Bilateral sensorineural hearing loss (SN) can impact auditory processing.
• Accurate sound localization is crucial for speech comprehension in complex acoustic scenes.
• Previous research has explored spatial hearing deficits in hearing loss, but less is known about multitalker scenarios.

Purpose of the Study:

• To investigate the impact of bilateral sensorineural hearing loss on speech source localization within a multitalker auditory scene.
• To determine if hearing loss affects the ability to segregate and localize individual speech streams when multiple talkers are present.

Main Methods:

• Participants with bilateral sensorineural hearing loss and normal-hearing controls localized a target speech word.
• Stimuli consisted of five simultaneous, distinct speech utterances presented via loudspeakers in a controlled room.
• Localization accuracy (error) was measured for the target word within the multitalker mixture and when presented alone.

Main Results:

• Listeners with bilateral sensorineural hearing loss exhibited significantly larger localization errors compared to the normal-hearing control group when localizing speech in a multitalker mixture.
• No significant differences in localization accuracy were observed between the groups when the target speech word was presented in isolation.
• These findings indicate a specific deficit in processing spatial information from concurrent sound sources.

Conclusions:

• Bilateral sensorineural hearing loss does not inherently impair fundamental spatial hearing abilities.
• The primary deficit lies in the degraded ability to create and utilize spatial representations of multiple simultaneous speech sources.
• This has significant implications for understanding real-world listening challenges faced by individuals with hearing loss.