- 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
- Eberhard Zwicker Hugo Fastl Ulrich Widmann Kenji Kurakata Sonoko Kuwano Seiichiro Namba
- 出版者
- Acoustical Society of Japan
- 雑誌
- Journal of the Acoustical Society of Japan (E) (ISSN:03882861)
- 巻号頁・発行日
- vol.12, no.1, pp.39-42, 1991 (Released:2011-02-17)
- 参考文献数
- 12
- 被引用文献数
- 46 87
The method for calculating loudness level proposed by Zwicker is standardized in ISO 532B. This is a graphical procedure and it can be tedious to calculate loudness level by this procedure. Recently, DIN 45631 has been revised including a computer program for calculating loudness level in BASIC which runs on IBM-compatible PC's. Since the NEC PC-9801 series computers are popular in Japan, the program has been modified for the NEC PC-9801 series computers and is introduced in this paper.
- 著者
- Yôiti Suzuki Hisashi Takeshima Kenji Kurakata
- 出版者
- ACOUSTICAL SOCIETY OF JAPAN
- 雑誌
- Acoustical Science and Technology (ISSN:13463969)
- 巻号頁・発行日
- pp.e23.66, (Released:2023-10-25)
- 参考文献数
- 14
As significant errors were reported in 1985 for the international standard related to equal-loudness-level contours (ELLCs) for pure tones, the earlier international standard was fully revised in 2003 as ISO 226:2003, after 18 years of revision work. Twenty years later, the standard has been revised again as ISO 226:2023. One motivation for the revision was to reflect the lowering of the threshold of hearing at 20 Hz by 0.4 dB in ISO 389-7:2019. In addition, the following two points of substance were revised: (1) implementation of the power exponent relating loudness perception to physical intensity formulated in an academic paper published in 2004, which describes the derivation of ELLCs relating to ISO 226:2003, and (2) adoption of mathematical expressions that preserve the appropriate number of significant digits. In this review, the process of the revision and the technical details of the changes are described. The differences from the 2003 edition are only 0.6 dB at most, and the 2023 standard can be regarded as the same as the 2003 edition in terms of practical use.
- 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.