Sampling Frequency of Digital Sound Sources Affects Psychophysiological States of Listeners

Abstract

High-resolution audio has a higher temporal and/or depth resolution than compact disks (CDs). Several researchers have suggested that inaudible high-frequency components of high-resolution audio might influence listeners’ psychophysiological states. Two types of digital sound sources with the identical frequency structure (<22 kHz) were created at different sampling rates (192 kHz and 44.1 kHz) by filtering out inaudible high-frequency components of an original sound source, which was an excerpt of natural environmental sounds recorded in 192-kHz/24-bit format. Twenty-four university students listened to the three sounds in a random order for five minutes each. Results indicated that the 192-kHz sound source compared to the 44.1-kHz sound source induced higher power in the theta (4.0–8.0 Hz) and slow alpha (8.0–10.5 Hz) bands of the electroencephalogram. However, no apparent differences were found in sound quality or subjective mood. These results suggest that digital sound sources with a higher sampling frequency than CDs influence the physiological state of listeners, although the difference might not be consciously perceived.