In structure of Japanese musical instruments, there are several devices which reflect special features of traditional Japanese music. On the other hand, common aspects of taste in timbre between Japanese and western instruments can be observed. This is regarded as an expression of the similar sense of beauty in sounds with each other's music. As examples of those peculiar devices, this paper describes (1) those for delicate and smooth pitch change observed in tall bridges and the frets of string instruments as well as in the large mouth holes and dented surface of wind instruments, (2) the peculiar bore shape of a Nohkan formed by insertion of a slender pipe called the “throat, ” and (3) a device called the “Sawari” which generates inharmonic components and prolongs the decay time of harmonic components and can be observed in a Biwa and a Shamisen. The common taste in the timbre described here are (1) similarity in frequency characteristic of bodies of a violin and a Biwa, both of which are evaluated as superior and (2) desirable features of spectrum pattern observed in Baroque recorder music and classical shakuhachi music.

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The comparative acoustical and psychoacoustical elements of the Javanese gamelan were studied with a focus on tuning, vibrational characteristics and associated perceptual effects. In addition to relating acoustical, perceptual, and musical frameworks to each other, we seek to clarify some common misconceptions about tuning modes, scales, and the assignment of pitch to metallophones which have inharmonic spectra. We found that the inharmonic modes of the spectra of the bars of the gamelan instruments saron demung, saron barung, and saron peking are described well by the standard physical theory of rectangular bars. The makers have tuned the bars by shaping so that harmonic partials also appear. The frequencies of the scale of the seven measured bars of each instrument (Low 6, Middle 1, 2, 3, 5, 6, High 1) are fit perfectly by an exponential function. Results of perceptual experiments show that, although many octave mismatches occur, both Indonesian and Western subjects generally matched a pitch chroma. In judging small-cents deviations from equi-pentatonic tuning, we found one professional Indonesian musician of four who could reliably discern them. We argue that the paradox of three different pathets (modes) for equi-pentatonic tunings can be explained by differing distributions of chroma based on Markof chains of order 0, 1, 2 or higher and other imposed formulaic and hierarchical structures, which we call chromals.

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Tapping sounds were measured for the varnished boards and the uncoated ones of Sitka spruce wood used for musical instrument soundboards, and the acoustical effect of varnishing was investigated from their sound power spectra. The Young's modulus and the internal friction were measured for these boards, and the equations for the case of a coated board were derived theoretically. From these experiments and theories, the important mechanisms were clarified. With varnishing, the sound power level decreased at low-frequencies (<300Hz), and it increased or decreased at high-frequencies (>3kHz) and overall. This difference in frequency characteristic variations was due to the difference in the variations of Young's modulus (E_R) and internal friction (Q_R^-1) in the direction, R, perpendicular to the grain. The level drop at low-frequencies was due to the shifting upwards of the lowest mode frequency with increasing E_R. For wood having a low E_R value the power level increased at frequencies above about 300Hz because of the larger increase of E_R, whereas for wood having a high E_R value it decreased at high-frequencies because of the larger increase of QR, -1. The varnishing is beneficial acoustically in the former but harmful in the latter regardless of varnish thickness.

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The purpose of the present study is to investigate the intelligibility of Japanese sung vowels (/a/, /e/, /i/, /o/, and /u/) uttered in isolation by trained soprano singers at higher pitches varied between cg (nominal 554 Hz) and A5 (880 Hz). The utterance was made in following two different singing manners to see whether the intelligibility is improved by singing manners or not: one, so-called “classical singing” or Bel Canto, named “Sonorous” for short in this study, putting priority on sonority, and the other, named “Phonemic” for short, instructed to emphasize phonemic quality as Japanese vowels, holding the sonority as much as possible. Phonemic intelligibility test was carried out diotically through a headset in a rondomized order over six singers, five vowels, five pitches and two singing manners. It was found that the effect of the singing manner is significant for /a/, /e/, /i/ and /o/, “Phonemic” singing manner being superior to “Sonorous” one for /a/, /e/ and /i/, while for /o/ vice versa. For /u/, the effect was not found. It was also confirmed that the effect of the voice pitch is significant for /i/, /o/ and /u/, in which the intelligibility decreases with increasing pitch, in particular for /i/ and /u/, while for /a/ and /e/ the effect is not significant. For /a/, a higher intelligibility was obtained compared with other vowels despite of pitch increase. For all the vowels, in particular for /o/, the misperception rate as /a/ increased with increasing pitch.

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A clarinet with all toneholes closed has been artificially blown and the respective variations of mouthpiece sound pressure, reed opening, velocity of air-flow from the artificial mouth into the instrument, and the pressure in the artificial mouth have been measured. In this paper, the details of these four waveforms are studied and compared for typical examples. Important results are:(1) The reed opening is proportional to the mouth-piece pressure for periodic vibrations, except for the reed-displacement limitations.(2) For nonperiodic vibrations, both the mouthpiece pressure and the reed opening must be observed because their variations are less correlated.(3) The air-flow velocity is roughly proportional to the reed opening when the pressure in the mouthpiece is not so high; however, it decreases with further increase of the mouthpiece-pressure which widens the reed opening. So far as our experimental results are concerned, no positive evidence of the air-flow from the instrument into the artificial mouth has been found.(4) The amplitude of the reed vibrations is limited by the mouth-piece lay or by the artificial lip or by both of these in most vibratory states, while the reed displacement is not restricted in a few states. No rule was found relating the reed-displacement limitation and the blowing parameters (lip-adjustment and blowing pressure).(5) The pressure in the artificial mouth used for these experiments has been isolated from the sounding clarinet system because it has been kept almost constant.

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The soundboard of a piano without strings vibrates in almost the same way as in an isotropic plate in a low-frequency region, because the anisotropy of its wooden material is compensated by its ribs, while the soundboard vibrates more locally in a high-frequency region. The boundary condition of the soundboard in a low-frequency region is a mixture of the fixed and simply supported conditions, whereas it becomes a fixed-edge state in a high-frequency region. Wher strings are added to the soundboard, they increase the resonance frequency of each vibration mode on the soundboard, and reduce its Q value. Characteristics of a soundboard can be quantitatively shown by measuring an admittance at the driving point of each string on the bridge. The admittance measured is also important to indicate the degree of influence of strings on the sound-board. The soundboard vibrates in a low-frequency range, reducing the amplitude of the fundamental vibration, and emphasizing its partials since the driving points are near the edge. In an intermediate-frequency region, the fundamental mode contributes very little to vibrations since it is low than the frequency range. The admittance in a high-frequency region is high due to local vibrations occurring between ribs. Other acoustic characteristics of the soundboard, such as its vibrations with a constant driving force, and the sound-pressure directivity of soundboards, have been investigated.

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Performances of two skilled amateur pianists were analyzed to investigate factors deter mining the impression of the equality of intensity in piano music. The results of the analysis showed that although the pianists tried to play every tone as equally as possible, not all the tones were played in equal intensity. The following two features were found in the performances:(1) The pattern of fluctuation was regularly repeated throughout the performance.(2) The peak level of each “playing unit” was remarkably kept constant compared with the fluctuation of each tone. The same tendency was also found in the performances of professional pianists. The results of the psychoacoustical experiment showed that when these features were destroyed, the impression of equality was degraded. These findings suggest that skilled pianists can maintain the impression of the equality of intensity by making good use of the characteristics of our auditory perception.

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