We report on a comparison of English and Japanese speech in goal-directed conversation in both telephone-only and multimedia environments. Factors considered are: disfluency, distribution of syntactic sentence types, deictic expressions and distribution of utterance intention types. Responses to a subjective survey of subjects' reactions to the communication modes are also discussed. Results have implications for constructing models of speaker and hearer, as well as for understanding the role of visual information in communication and for the design of a machine translation system integrated with multimedia technologies.

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In this paper, effects of irrelevant background speech and speech-simulating noise on working memory were investigated. In two experiments which were carried out in Germany and Japan using the same procedure, with totally 12 volunteers serving as subjects, we tested the long-term effects of habituation to the background sound by repeating the experimental sessions three times with intervals of about one week. Using a serial recall task it could be shown that natural background speech impaired significantly the performance. This result is corresponding with former results found by other researchers. Speechsimulating noise, however, did not reveal any effects. The reasons for this lack of effects are discussed. Most important, however, is the finding that there is clearly no effect of habituation to the background speech. While the over-all performance is improved by repeating the experimental sessions, the effects of the experimental background sounds are stable. This result is interpreted in terms of an information-processing approach to the orienting reflex theory. The practical implications of the results are discussed as well.

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The representative spectrum of traffic noise is expressed in terms of the normalized Aweighted sound pressure level, δL_n. Assuming that the traffic noise annoyance is measured by the time-average sound level, the dependence of δL_nupon the traffic speed and the percentage of heavy vehicles has been derived. For traffic without heavy vehicles, an increase in traffic speed causes δL_n to decrease at low frequencies. The presence of heavy vehicles destroys the dependence of δL_n upon the traffic speed and may increase the value ofδL_n a few decibels at low frequencies.

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This paper investigates the characteristics of piano sound using the waveforms of velocity of vibration of strings, the waveforms of driving force and velocity of vibration of the soundboard, and waveforms of sound pressure. The waveforms for the investigation were generated by using a analog simulator so that the separation of conditions is easy. A pulse generated by striking a string with a hammer propagates along the string and reflects against the soundboard. This drives the soundboard producing its vibration, and a part of vibration energy radiates from the soundboard producing piano sounds. The soundboard vibration contains both forced and free vibrations. The latter is influenced by the driving point admittance of the soundboard, and this plays an important role in determining the piano timbre. Still more the characteristics of piano sound are clarified using waveforms obtained by digital simulation and their spectra.

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