Interactions between egocentric and allocentric spatial coding of sounds revealed by a multisensory learning paradigm

Area of Science:

• Auditory neuroscience
• Psychoacoustics
• Human sensory systems

Background:

• Spatial hearing initially relies on head-centered (egocentric) coordinates.
• The brain also processes sounds in relative (allocentric) coordinates.
• The interaction between these reference frames for spatial hearing is not well understood.

Purpose of the Study:

• To investigate if allocentric spatial hearing training can enhance egocentric sound localization.
• To explore the relationship between egocentric and allocentric spatial hearing reference frames.
• To assess the efficacy of multisensory training for improving sound localization with monaural hearing.

Main Methods:

• Developed a novel allocentric spatial hearing training paradigm.
• Compared two groups of participants undergoing 4-day multisensory training: one allocentric task, one egocentric task.
• Included a no-training control group for comparison.
• Assessed egocentric sound localization performance before and after training in monaural listening conditions.

Main Results:

• Egocentric sound localization improved in the horizontal plane for all groups, particularly in the space ipsilateral to the ear-plug.
• Unexpected improvements in the no-training group underscore the need for control groups in re-learning studies.
• Qualitative differences in performance changes between trained and untrained groups were observed.

Conclusions:

• The study provides initial evidence that allocentric and multisensory training may aid sound localization re-learning.
• The findings highlight the importance of control groups in auditory training research.
• Suggests potential for targeted training to improve spatial hearing in challenging listening conditions.