Auditory steady-state responses and speech feature discrimination in infants

Area of Science:

• Auditory Neuroscience
• Developmental Psychology
• Speech-Language Pathology

Background:

• Assessing auditory processing in infants is crucial for early intervention.
• Speech feature discrimination (SFD) abilities are key indicators of auditory development.
• Auditory steady-state responses (ASSRs) provide objective measures of auditory system function.

Purpose of the Study:

• To investigate the correlation between auditory steady-state responses (ASSRs) and speech feature discrimination (SFD) in young infants.
• To assess the relationship between objective electrophysiological measures and behavioral auditory perception.
• To understand how audibility of complex auditory stimuli relates to speech processing in early development.

Main Methods:

• ASSRs were recorded using complex toneburst stimuli in 17 infants and 21 adults with normal hearing.
• SFD abilities were measured using a visual-reinforcement procedure to detect changes in speech sounds (/ba/ to /da/).
• Threshold and input-output functions for ASSRs were determined by systematically varying stimulus levels.

Main Results:

• Group mean correlations between SFD performance and ASSRs ranged from 0.64 to 0.99.
• High correlations were observed for ASSRs across all stimulus components with /ba/-/da/ discrimination.
• Individual subject correlations between ASSRs and SFD scores were modest, suggesting variability.

Conclusions:

• ASSRs and SFD results indicate that the audibility of stimuli is a significant factor.
• The findings suggest that ASSRs can reflect the audibility of speech-relevant acoustic features in infants.
• This study highlights the link between objective auditory measures and behavioral speech perception in early development.