Subjective Effects of Sound Absorption and Investigation of Reverberation Times in Modern Japanese Dwellings

This study aimed to reveal the influence of sound absorption in general dwellings on the subjective evaluation of acoustics. First, a subjective experiment was conducted using a full-scale room model. The results indicate that the feelings of silence and serenity can be experienced at absorption coefficients above 0.17, particularly above 0.25. Additionally, we used the recorded binaural sounds for a subjective test instead of using a full-scale room model. This trial showed that the reverberance, feeling of silence, and feeling of serenity can also be evaluated using a headphone listening test. We also measured the reverberation times and recorded the sound environments in three bedrooms, three living and dining (LD) rooms, and three child rooms in modern Japanese dwellings. The average absorption coefficients of the LD and child rooms were lower than 0.17, in the range of 500 Hz to 4 kHz. Therefore, we analyzed the subjective effect of absorption through a psychological test using binaural recorded sounds. The bedrooms with absorption coefficients of 0.18–0.23 were significantly less reverberant, quieter, and more serene than the other rooms.