Autophonic loudness perception in Parkinson's disease

Area of Science:

• Neuroscience
• Speech Science
• Auditory Perception

Background:

• Autophonic (self-generated) speech loudness perception is influenced by non-auditory factors.
• Parkinson's disease (PD) is associated with speech deficits, but the underlying perceptual mechanisms are not fully understood.

Purpose of the Study:

• To investigate whether sensorimotor integration deficits in Parkinson's disease affect autophonic loudness perception.
• To determine if individuals with PD rely more on auditory feedback for speech regulation.

Main Methods:

• Loudness magnitude estimations were collected from individuals with and without PD.
• Four conditions were tested: normal, perturbed, and masked auditory feedback during self-produced speech, and passive listening to recorded speech.
• Slopes and intercepts of loudness functions were analyzed across conditions and groups.

Main Results:

• Both groups showed different loudness functions for autophonic versus passive listening.
• Parkinson's disease subjects exhibited increased variability and altered loudness regulation under auditory masking compared to controls.
• Individuals with PD did not demonstrate the same shift in intercept values as controls under masking.

Conclusions:

• Parkinson's disease is associated with deficits in sensorimotor integration crucial for autophonic loudness.
• Individuals with PD appear to depend more heavily on auditory feedback to compensate for these underlying perceptual deficits.
• Findings highlight the role of non-auditory feedback mechanisms in speech perception and regulation in PD.