The light pattern method is often useful for the calibration of recorded signal levels of phonograph records, however, it is restricted to the low frequencies because the edges of the pattern become obscure at higher frequencies. It can be theoretically derived and experimentally proved that when a LASER beam is used as the light source in the light pattern method, the pattern changes into a pattern with the bright and dark stripes, and therefore, recorded levels can be calibrated more accurately by analyzing the bright and dark striped pattern instead of the pattern width.

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A microphone with simple construction, using a bimorph diaphragm made from a composite piezoelectric polymer sheet, is described. A composite of lead-titanatezirconate powder and polyvinylidenefluoride and/or fluorinated rubber is useful, because its characteristics can be widely controlled by varying its composition, and it is easy to mold into a sheet. A symmetric bimorph structure using two composite polymer sheets is convenient for the structure. Microphone response is calculated, and it is concluded that a microphone, some 10-20 mm in diameter, shows of -70∼-90 dB response (re volt/microbar) as a telephone microphone. Several experiments confirm these results.

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When we listen to vibrato tones, we perceive not only frequency fluctuation but also somewhat steady pitch. This pitch sensation of vibrato tones is defined as “principal pitch.” The principal pitch of vibrato tones is located around its carrier frequency, by a method of adjustment. As the location of principal pitch of vibrato tones has the width proportional to its extent of frequency changing, it is impossible to be located more precisely. The principal pitch of symmetrical trill tones is located around its carrier frequency, too. The location of principal pitch of asymmetrical trill tones is shifted in the direction of the longer one between high frequency interval and low frequency interval. This means that the location of principal pitch of frequency modulated tones is defined not only by higher and lower extremes of modulation extent but also by the whole process of frequency changing. It is more shifted than the simple time average of frequency changing. From these experimental results we suppose the pitch averaging mechanism in the auditory process to perceive principal pitch of frequency modulated tones. In this process, this mechanism samples pitch changing continuously, registers in sensory store, and averages every certain moment. When a pitch distribution of frequency modulated tones is asymmetrical, this mechanism accomplishes its function after emphasizing the large part of the distributio.

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In perception of regular sequence of stimulus sounds that is neither too rapid nor too slow, we tend to perceive it as rhythmic. In the present study, we investigated the degree of temporal distortion intervened in the sequence which was needed in order for listeners to be able to report an irregularity, and we also investigated the timing patterns of the repetition of monosyllables as a response to the regular sound sequence. The degree of distortion which afforded 50% judgments of detection was found to be about 6% in the region of rates slower than 3 times per second, and about 7.6∼8.9% depending upon the type of distortion in the region of rates more rapid than 4 times per second. Another experiment showed that a negative correlation between the time intervals of neighboring vicinity which suggested an adjusting mechanism was found only in the region of rates slower than 3 times per second. From the results, the author tentatively concludes that the ongoing processing mechanism works in the region of rates slower than 3 times per second and the wholistic processing mechanism works in the region of rates more rapid than 3 times per second.

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An approach to speech synthesis of Thai which is a tone language is presented. The stored data are presently cepstral parameters of consonant-vowel-(CV-), vowel-consonant-(VC-) and vowel (V) demisyllables. Speech is produced by concatenating stored cepstrum-coded demisyllables, providing pitch contour for each of monosyllabic sounds and synthesizing the speech through the log magnitude approximation (LMA) digital filter. Interpolation at boundaries of demisyllables is linear. For each tone, the f0 contours are simply synthesized from the information of a rudimentary contour specified by a third order polynomial in the domain of pitch period. The details on determining a rudimentary f0 contour for each tone, segmentation for demisyllable library, and rules for concatenation and pitch assignment are described, along with experimental evaluation tests and discussions.

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