The effects of the fluctuating noise were compared to that of the constant noise. The spectral density of the fluctuating noise varies as 1/f. The frequency characteristic of the noise was modeled on that of the air-conditioner noise. Ten male students were exposed to the noise for 60min at 85 dB(A) [Leq]. EEG and ECG were recorded for 70min including 5min-rest before and after exposure, respectively. Four EEG components (delta, theta, alpha and beta) derived by the power spectral analysis and slopes of the spectra of heart rate variability (HRV) were obtained for 65min (before and during exposure). Results of the subjective assessment to the exposed noise show that the rate of complaint of uncomfortable mood to the 1/f fluctuating noise is higher than that of the constant noise, but there is no significant difference among them. Slow waves of EEG increased, heart rates decreased and slopes of the spectra of HRV decreased during noise exposure, however no significant difference between two noise conditions were found. Contrary to our expectation, the 1/f fluctuating noise may not be comfortable in this experiment.

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This paper proposes a new procedure for performance analysis for a voice input system, especially on the effect of “similar word pair characteristics” and on “human factors” in the voice input operation. The principle of the disparity method into the analysis is introduced first. Next, the classification procedure for substitution errors in word pairs on the disparity coordinates and the axis of the disparity index are demonstrated.
Applying this method, the substitution errors in word pairs, obtained from the experimental results are precisely analysed. A practical guidance is given for improvement in the voice input performance concerning similar word pair characteristics and the human factors.
One formal procedure for the voice input system performance analysis is given through this investigation.

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An experiment was carried out to evaluate learnability and performance of Japanese command system. Twenty Japanese novices were participated in the experiment and played a command-driven robot control simulation game repeatedly. The game was programed to record the time of events occured during the game. Four command-sets consist of Japanese words and syntax are used. The command verbs are changed between the command-sets, the verbs of command-set A represent actions of the robot, the verbs of the B are two-letter abbreviations of the A, the verbs of the C and D are nonsense syllables but the C has higher meaningfulness. The results show that in terms of the mean latency, interval time from the system's response to the user's reaction, and mean (duration) time to input command string the A and B were significantly shorter than the C and D. Accordingly, it is suggested that the command names that have higher meaningfulness have the advantage in learnability and performance of command system.

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Detectability and discriminability of nonsense lists of syllables, composed of five synthesized Japanese vowels, in noise were investigated. The S/Ns enabled a subject to detect and discriminate the lists of syllables were measured as detectability and discriminability respectively. In the first experiment, these S/Ns were measured for young (19-23 years old) and old (50-63 years old) subjects. With respect to discriminability, old subjects required greater S/N than young ones did in average; the difference was approximately 9dB. Contrastingly, with respect to detectability, old subjects required much the same S/N as young ones did in average. In the second experiment, these S/Ns were measured for young subjects under conditions simulating deteriorations of puretone threshold and frequency selectivity. The findings suggests that the deterioration of frequency selectivity plays an important role in poor discriminability exhibited by old subjects in the first experiment. Implications of findings are also discussed about functional deteriorations of the auditory system with age.

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The purpose of the present study was to determine whether lateral differences were found in tactile perception of letter of the alphabets and number of dots in normal subjects. The subjects were divided into 80 pure right-handed men and the other 10 men by handedness questionnaires. The stimulus was presented to the left or right index finger by active touch. The subjects were required to determine the letter or number of dots that they felt. The result showed that tactile perception of letters and numbers of dots was significantly more accurate with the left hand than with the right hand in pure right-handed group. It was more noticeable with letters. The reverse trend was found in the other group. These results suggested that the letters of the alphabet were processed as figures by the right cerebral hemisphere in the pure right-handed subjects.

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An olfactory equation was proposed as for relationship between concentration of an odorant and its perceived intensity. The equation was derived from three underlining processes of olfactory perception, namely (1) absorption of odor molecules to lipid membrane, (2) combination of the molecules with receptor molecule, and (3) neural process in olfactory nervous system. Validity of the proposed equation was examined experimentally as for relationship between concentration of odorant and perceived intensity. Forty odorants, in 8 homologous series, were presented to 6 subjects (4 males and 2 females), who rated on 8 point scale.
Results. It was clear that the olfactory equation gave better fit to the perceived intensity, than equations of Weber-Fechner or Stevens predict. Furthermore, close relationship was found between regression coefficients and odor thresholds. Hence, if an odor threshold is estimated from some physicochemical parameters of an odorant, its olfactory equation may be inferred.

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