Hearing loss is associated with delayed neural responses to continuous speech

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Speech Processing

Background:

• Sensorineural hearing loss affects auditory processing.
• Neural mechanisms underlying speech perception in hearing-impaired individuals are not fully understood.
• Understanding these mechanisms is crucial for developing effective interventions.

Purpose of the Study:

• To investigate the impact of sensorineural hearing loss on the neural processing of continuous speech.
• To compare neural responses to speech in hearing-impaired listeners versus normal-hearing peers.
• To explore the relationship between hearing loss severity, neural response latency, and speech understanding.

Main Methods:

• Utilized a forward modeling approach to analyze neural responses.
• Compared 14 adults with sensorineural hearing loss to age-matched normal-hearing controls.
• Recorded neural responses to continuous speech in quiet and noisy conditions.

Main Results:

• Hearing-impaired listeners exhibited increased neural tracking and delayed neural responses to speech in quiet.
• Neural response latency increased with the degree of hearing loss.
• While neural tracking decreased with poorer speech understanding in both groups, latency trends differed, particularly in noise.
• Hearing-impaired listeners did not show the typical increase in latency with background noise seen in normal-hearing individuals.

Conclusions:

• Neural response latency serves as an indicator of neural speech processing efficiency.
• Hearing loss leads to less efficient neural speech processing, requiring more brain resources and time.
• This inefficiency is gradual and present even in quiet, suggesting amplification alone is insufficient.
• Findings highlight the need for strategies beyond simple amplification to address hearing loss impacts on speech perception.