Archives of Acoustics, Online first
10.24425/aoa.2024.148765

Auditory Spatial Illusion – A Psychoacoustic Study in Young Adults

Mehri MALEKI
Iran University of Medical Sciences
Iran, Islamic Republic of

Mohsen AHADI
Iran University of Medical Sciences
Iran, Islamic Republic of

Amirsalar JAFARPISHEH
University of Social Welfare and Rehabilitation Sciences
Iran, Islamic Republic of

Amin ASGHARZADEH
Iran University of Medical Sciences
Iran, Islamic Republic of

Alireza Akbarzadeh BAGHBAN
Shahid Beheshti University of Medical Sciences
Iran, Islamic Republic of

Reyhane TOUFAN
Iran University of Medical Sciences
Iran, Islamic Republic of

The Franssen illusion, or Franssen effect (FE), is one of the auditory spatial illusions. Few studies have explored the FE, and the mechanisms underlying it remain unknown. The present study was conducted to clarify the FE occurrence with different tasks and presentation modes in young adults. It also sought to investigate possible neurophysiological similarities between interaural time difference (ITD) cue processing and FE perception. FE perception was evaluated using two different tasks and two presentation modes (i.e., insert phones and loudspeakers). Sound reflections (reverberation) were presented in the diffuse field (loudspeaker mode). ITD performance was investigated using different stimuli delivered via insert phones. No significant difference between the two FE perception tasks was found (F1;25 = 0:138, p = 0:713). However, the FE perception showed a significant difference between the two presentation modes (F1;25 = 434:03, p < 0:001). Spearman’s correlation did not reveal a significant relationship between FE perception and ITD scores (p > 0:05).
The current findings show the importance of reverberation in the FE occurrence. Also, the non-significant correlation between the results of the behavioral binaural temporal resolution test and FE perception in young people with normal temporal resolution may indicate that room reflections (reverberation) complicate the ability to process ITDs (rather than poor ITD processing for the “steady state” portion of signal).
Keywords: auditory spatial illusions; the Franssen effect; interaural time difference; binaural temporal resolution
Full Text: PDF
Copyright © 2023 The Author(s). This work is licensed under the Creative Commons Attribution 4.0 International CC BY 4.0.


DOI: 10.24425/aoa.2024.148765