著者
Kaoru Ashihara Kenji Kurakata Tazu Mizunami Kazuma Matsushita
出版者
一般社団法人 日本音響学会
雑誌
Acoustical Science and Technology (ISSN:13463969)
巻号頁・発行日
vol.27, no.1, pp.12-19, 2006 (Released:2006-01-01)
参考文献数
25
被引用文献数
10 27

Hearing thresholds for pure tones from 2 kHz to 28 kHz were measured. A 2AFC procedure combined with a 3-down 1-up transformed up-down method was employed to obtain threshold values that were less affected by listener’s criterion of judgment. From some listeners, threshold values of 88 dB SPL or higher were obtained for a tone at 24 kHz, whereas thresholds could not be obtained from all participants at 26 kHz and above. Furthermore, thresholds were also measured under masking by a noise low-pass filtered at 20 kHz. At frequencies above 20 kHz, the difference of threshold values between with and without the masking noise was a few decibels, indicating that the tone detection was not affected by subharmonic components that might have appeared in the lower frequency regions. The results of measurement also showed that the threshold increased rather gradually for tones from 20 to 24 kHz whereas it increased sharply from 14 to 20 kHz.
著者
Kenji Kurakata Tazu Mizunami Kazuma Matsushita
出版者
ACOUSTICAL SOCIETY OF JAPAN
雑誌
Acoustical Science and Technology (ISSN:13463969)
巻号頁・発行日
vol.34, no.1, pp.26-33, 2013-01-01 (Released:2013-01-01)
参考文献数
20
被引用文献数
2 7

The sensory unpleasantness of high-frequency sounds of 1 kHz and higher was investigated in psychoacoustic experiments in which young listeners with normal hearing participated. Sensory unpleasantness was defined as a perceptual impression of sounds and was differentiated from annoyance, which implies a subjective relation to the sound source. Listeners evaluated the degree of unpleasantness of high-frequency pure tones and narrow-band noise (NBN) by the magnitude estimation method. Estimates were analyzed in terms of the relationship with sharpness and loudness. Results of analyses revealed that the sensory unpleasantness of pure tones was a different auditory impression from sharpness; the unpleasantness was more level dependent but less frequency dependent than sharpness. Furthermore, the unpleasantness increased at a higher rate than loudness did as the sound pressure level (SPL) became higher. Equal-unpleasantness-level contours, which define the combinations of SPL and frequency of tone having the same degree of unpleasantness, were drawn to display the frequency dependence of unpleasantness more clearly. Unpleasantness of NBN was weaker than that of pure tones, although those sounds were expected to have the same loudness as pure tones. These findings can serve as a basis for evaluating the sound quality of machinery noise that includes strong discrete components at high frequencies.