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In recent years, a lot of attention has been directed at designing various sounds that are treated as noise, such as automobile acceleration sounds and cleaner sounds. The idea of sound being a normal part of product operation has permeated society. We focused on sound design and evaluated it with 11 kinds of button sounds for car audio main units. At present psychoacoustics metrics (loudness, sharpness, etc.) which took the frequency characteristic of the complicated human auditory system into consideration, has come to be used for evaluation of the various sounds. However, button sounds are not steady and continuous. In order to accurately represent button sounds, it is necessary to analyze time characteristics as well as frequency characteristics; this is known as time-frequency (t - f ) representation. In this study, an impression was extracted by the semantic differential (SD) method, and the relevance of that impression was investigated by the wavelet transform (WT). The t - f resolution features of WT are similar to an auditory t - f resolution feature. As a result, the button sound impressions were classified into an esthetic factor, metallic / clarified factor and powerful / massive factor on the basis of these results, and these impressions could be visualized by the WT distribution. Next, we confirmed whether or not the impression changed when a sound that generated a bad impression was processed using an adaptive control into a sound that generated a good impression.

A lot of attention has been directed at designing various sounds that are treated as noise, such as automobile acceleration sounds and cleaner sounds. The reason is that the idea of sound being a normal part of product operation has permeated society. We focused on sound design and evaluating it for 11 kinds of button sounds. First, an impression was extracted by the semantic differential (SD) method, and the relevance with a time frequency analysis was investigated. Next, we confirmed whether or not the impression changed when a sound that generated a bad impression was processed using adaptive control into a sound that generated a good impression.

In this study, we considered audio equipment evaluation using the sound of music. Audio amplifiers were set up as the evaluation targets, and sound quality differences between them were visualized by a wavelet analysis using an actual musical sound signal. We considered the cause of these differences and then tried to connect the sound impression to an analysis result. WT ( wavelet transform ) of the sound of music was carried out to evaluate two amplifiers. The sound quality of amplifier A related to the esthetic factor of the "depth " and has been analyzed as the high region of WT, and that of amplifier B related to the force factor of the "depth " and has been analyzed as the low region of WT. Thus, we were able to visualize the impression of listening to the music by correlation of the auditory experiment and wavelet analysis.

In recent years, speech recognition systems have been introduced in a wide variety of environments such as vehicle instrumentation. Speech recognition plays an important role in ships ' chief engineer systems. In such a system, speech recognition supports engine room controls, and lower than 0-dB signal-to-noise ratio (SNR) operability is required. Therefore, this study focuses on a recognition system that uses body-conducted signals. Such signals are seldom affected by background noise, and thus a high recognition rate can be expected in low SNR environments such as an engine room. However, within the construction of such systems, in order to create models specialized for body-conducted speech, learning data consisting of sentences that must be read in numerous times is required. Therefore, in the present study we applied a method in which the specific nature of body-conducted speech is reflected within an existing speech recognition system with only small numbers of vocalizations.

In recent years, much attention has been directed at the sound design which designs various sound treated as noise, such as automobile acceleration sound and cleaner sound, because the point of view sound is a part of products, has permeated. This research considered the sound design and its evaluation about 11 kinds of the button sounds. First, the impression was extracted by the SD method and relevance with time frequency analysis was investigated. Moreover, we also confirmed that an impression changed, when the sound of a bad impression is processed into the sound of a good impression using adaptive control.

Hysteresis characteristics, which are similar to those observed in ferroelectric crystals, are found in uniaxially stretched poly(vinylidene fluoride) under a high electric field above 300 kV/cm at room temperature. Various transducers such as stereophonic headphones, tweeters, microphones and phonograph cartridges have been developed with polarized poly(vinylidene fluoride) films. These transducers have quite simple structures because the diaphragms are piezoelectric films and involve transducing function in themselves.

An electro-acoustic transducer comprising a flexible film of piezoelectric material, at least one electrode provided on one side of said film amd a plurality of electrodes provided on the other side of said film to form a piezoelectric diaphragm and said piezoelectric diaphragm is imparted with a locally differing resiliency and/or tension, is provided. By using this piezoelectric electro-acoustic transducer in a loudspeaker, it is possible to improve acoustic characteristics thereof particularly in a high frequency range, to obtain a variety of acoustic characteristics and to effect motional feed back to minimize distortion of reproduced sound without involving any difficulty in manufacturing or affecting proper performance of the transducer.