On the relationship between the subjective preference of sound fields and the α-brain wave in both hemispheres

Abstract

For the purpose of finding possible brain activity corresponding to the subjective preference of sound fields, an attempt was made to analyze the effective duration (τe) of the running autocorrelation function (ACF) in the α-wave range (8–13 Hz) in both hemispheres. As the sound source, a music motif (Arnold: Sinfornietta of Opus 48, a 5 s piece of the 3rd movement) was selected. When the temporal factor of the sound fields (the delay time of reflection Δt1) is changed, the values of τe in the α wave in the left hemisphere correspond well with the subjective preference, but not in the right hemisphere. A long value of τe in the α wave indicates the preferred condition. When the reverberation time Tsub is changed, the values of τe in the α wave were much longer at the preferred reverberation time [Tsub]p=1.2 s than those at Tsub=0.2 or 6.4 s in the left hemisphere. On the other hand, when the spatial factor of the sound fields (IACC) is changed, the right-hemisphere dominance is achieved by the analyses of the value of τe in the α wave (p<0.001).