Neural timing is linked to speech perception in noise

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Speech Processing

Background:

• Understanding speech in background noise is a challenge for all listeners.
• Noise disrupts neural synchrony, degrading speech representations at cortical and subcortical levels.
• These challenges are more pronounced in clinical populations, such as children with learning impairments.

Purpose of the Study:

• To investigate the hypothesis that listening-in-noise difficulties are linked to degraded processing of timing information at the brainstem level.
• To compare brainstem responses to speech syllables in children with varying speech-in-noise (SIN) perception and reading abilities.
• To examine the effects of competing multitalker babble on neural responses.

Main Methods:

• 66 children (ages 8-14) were divided into top and bottom groups based on SIN perception and reading performance.
• Brainstem auditory evoked potential (BAEP) responses to speech syllables were recorded in quiet and noisy conditions.
• Neural response timing was analyzed and compared between groups.

Main Results:

• In quiet conditions, neural response timing was similar between groups.
• In noise, children in the bottom SIN and reading groups showed greater neural delays compared to the top groups.
• These timing delays were specific to the noise-vulnerable formant transition of the speech syllable.

Conclusions:

• Background noise disrupts neural timing in the brainstem.
• Greater neural timing disruptions in noise are associated with poorer speech-in-noise perception.
• Brainstem timing deficits may underlie difficulties in understanding speech in challenging auditory environments.