Pinna shape similarity from excitation-inhibition patterns

Area of Science:

• Auditory Neuroscience
• Acoustics
• Biomedical Engineering

Background:

• Head-related impulse responses (HRIRs) capture how pinna shape influences sound localization.
• Auditory brainstem models offer insights into processing spectral cues.
• Excitation-inhibition (EI) patterns provide a compact representation of spectral symmetry.

Purpose of the Study:

• To assess pinna shape similarity using EI patterns.
• To investigate the relationship between EI-derived ear clusters and elevation localization.
• To identify specific morphological features affecting auditory perception.

Main Methods:

• Extracted pinna-related impulse responses and converted them into EI patterns.
• Clustered individuals based on interaural spectral difference (ISD) and then by morphology.
• Synthesized HRIRs with representative average ear shapes (RAES) for perceptual testing.
• Conducted a virtual listening experiment to assess elevation localization accuracy.

Main Results:

• Clustering revealed spectral and morphological ear groups.
• Perceptual testing showed reduced elevation localization accuracy with larger conchae.
• Localization errors correlated with mismatches in concha antihelix valley to intertragic notch dimensions.

Conclusions:

• EI-based clustering effectively captures pinna morphology relevant to auditory perception.
• Specific ear morphological features, like concha size, significantly impact median plane elevation localization.
• This approach offers a novel method for analyzing and understanding pinna shape variations and their perceptual consequences.