An analysis is presented for the free vibration of joined hemispherical-cylindrical shells. This kind of shell is an approximate model of Japanese hanging bell. For this purpose, the governing equations of vibration of a hemispherical shell, including a cylindrical shell as a special case, are written as a coupled set of first order differential equations by using the transfer matrix of the shell. Once the matrix has been determined, the entire structure matrix is obtained by the product of the transfer matrices of the shells, and the frequency equations are derived with terms of the elements of the structure matrix under the boundary conditions. The method is applied to the shells with various axial lengths and wall thicknesses, and the natural frequencies and the mode shapes of vibration are calculated numerically. The results are presented, clarifying the vibration characteristics of the joined shells.

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A language design of typed music is presented for the performance of the piano and piano-like musical instruments with the aid of computer. Here, “typed music” is defined as a computer-readable document that specifies the sequence of sounds to be rendered. The main concern is the high-level, quantitative description of musical gesture. The proposed language, named MUSE, provides this feature with (1) the organization of notes into a hierarchical structure, and (2) the parameterization of interpretive practice into terms of dynamics, agogics, articulation, shift, and the damper motion. By using these, the user can put the desired gesture, including a finer temporal variation of performing velocity, both locally and globally in time and voice.

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In order to provide the fundamental knowledge on outer and middle ear of children, acoustic impedance measurements were performed on 205 subjects. They ranged from 3 years old to 11 years old and had normal hearing. We utilized the acoustic inverse method for reconstruction of the ear canal area functions. The results show (a) the children have smaller ear canal radius than the adults and (b) the ear canal volume and the ear canal radius increase as a function of the age. The acoustic impedance at the eardrum were calculated from the reconstructed area function of the ear canals and the measured reflection data. It is shown that (c) mean resistance of the eardrum impedance remains between 300 and 350 cgs acoustic ohms above 2 kHz, and the value is not so much different from the reported data on the adults. On the other hand, (d) middle ear of the children has small compliance and its values approach to the adults data as the age increases. This is evident in lower frequencies below 1 kHz.

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This paper describes the experimental results on the relation between sound duration up to 10 s and loudness of a tone burst. There have been many studies on this phenomenon, but most of them report only the results for sound duration below 500 ms. Most investigators believe that loudness saturates at about 300 ms. In our experiments the method of constant stimuli was used, and the loudness of 1 kHz tone bursts with durations between 0.05 and 10 s was compared with comparison stimuli with duration of 0.2 s or 1 s. The results show that growth of loudness is seen even for durations beyond 500 ms.

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