Tohru Kato

Auditory and Visual Interaction in the Aesthetic Evaluation of Environment

This study examined auditory and visual interaction in the aesthetic evaluation of the environment. Road traffic noise, sounds from leaves, and motion pictures coherent to auditory stimuli were used. There were four conditions: only auditory stimuli were presented in condition A, only visual stimuli in condition V, both auditory and visual stimuli in condition A+V, and after both auditory and visual stimuli were presented together, auditory stimuli were presented alone and judged in condition (V)A. A semantic differential technique indicated that scenery that included green plants contributed to the improvement of the environment even if only shown as an image. A scene with many cars gave a negative impression. However, even if the sound from the cars was audible, visual masking by green plants seemed effective in reducing the negative impression of road traffic noise.

Psychological Evaluation of Waterside Space Using Audio-Visual Information

In order to investigate the effect of water sound on subjective impression, an experiment on the evaluation of the waterside space using audio-visual information was conducted. The interaction of audio-visual information and the relation between the physical characteristics of sound from water and the impression were examined. The experiment consisted of three conditions; only sound was presented in condition A, only visual image in condition V, and both sound and visual image in condition A+V. Impressions were estimated using the semantic differential. The results showed that the visual images have a great effect on the impression of waterside space and that as the sound pressure level of low frequency components becomes higher, the sound tends to be perceived as being more unpleasant.

Predicting overall reaction to multiple noise sources

The validity of models predicting overall human response to complex sound environments, which are constituted of road traffic and railway noises, is discussed using results of psychological experiments carried out both in a laboratory and outdoors, as well as by using results of social surveys. Existing predictive models (energy summation model, independent effects model, response summation model, and so on) were applied to the data. The result shows that the simple energy summation model gives the poorest predicting ability in every case. It suggests that differences of response among different noise sources must be considered. The effective level D of road traffic noise relative to railway noise was calculated using Ollerhead’s response summation model as approximately 10 dB in the laboratory experiment. The D values decreased as compared to the above value in cases of field experiments and social surveys, but it was still clear that the contribution of road traffic noise to the overall judgment was gre...

Auditory memory and evaluation of environmental sounds

A series of experiments were conducted concerning the memory of environmental sounds. Twelve kinds of sound were presented with soft background noise of about 6 min to participants. They were asked to recall or recognize the sound sources and to judge the loudness of the recalled or recognized sounds some period after they listened to the sounds. The recalled or recognized loudness was examined in relation to the length of the period between the presentation of sounds and the judgment of loudness, the method to measure the memory, LAeq of each sound source, etc. The results suggest that it is possible to judge the loudness of the memorized sounds and that the judgments seems reliable.

Evaluation of the loudness of stationary and non-stationary complex sounds

In our sound environment, there are various complex sounds including both stationary and non-stationary sounds. It is important to examine the relation between the loudness and the physical metrics in order to evaluate and control the sound environment. The temporal patterns of non-stationary sounds in daily life environment, such as road traffic noise, construction noise, speech and music, are different from each other. It would be desirable to evaluate the loudness of both stationary and non-stationary sounds with various temporal and spectral characteristics by the same metric in the evaluation of the loudness. It is needless to say that the metric should have a good relation with the subjective impression. From physical viewpoint, sounds with various temporal patterns including stationary sounds can be measured by a single scale on the basis of energy. In this paper, a single common metric for the evaluation of the loudness of both stationary and non-stationary sounds is examined by conducting a psych...

Psychological evaluation of sound environment with mixed sources

In order to make the experimental situations closer to actual situations, experiments have been conducted in field conditions, where various sounds were audible. The results suggested that generally speaking, LAeq was a good measure for the evaluation of environmental noises. However, there were some cases where LAeq did not show good correspondence with subjective impressions. On the basis of the results of the field experiments, an experiment was conducted in a laboratory situation with precisely controlled stimuli in order to examine the applicability of LAeq to sound with mixed sources. Sounds which consisted of aircraft noise, road traffic noise, and train noise were used. Three events of each noise source were included in 15‐min stimuli and the duration of road traffic noise was varied in three stimulus conditions. Subjects were asked to judge instantaneous loudness using the method of continuous judgment by category. After instantaneous judgment was over, overall impression of loudness of each soun...