Sonoko Kuwano

Continuous judgment of level-fluctuating sounds and the relationship between overall loudness and instantaneous loudness

SummaryThe present investigation was designed to examine the most appropriate duration of instantaneous loudness and to find out the relationship between overall loudness and instantaneous loudness using 20-min road traffic noise. Instantaneous loudness was judged using the method of continuous judgment by category. The results suggest that instantaneous loudness is determined by the sound energy averaged during the 2.5-s period preceding each judgment, the duration of which seems to reflect the psychological present. It was also found that overall loudess is not an average of the instantaneous loudness of every moment, but that it is based on the instantaneous loudness above a certain level.

On the judgment of loudness, noisiness and annoyance with actual and artificial noises

Abstract Loudness, noisiness and annoyance were judged for 36 stimuli by Japanese and German subjects. In experiment 1, actual noises such as aircraft and road traffic noise were used. In experiment 2, artificial noises were used. Their level patterns were simulated to correspond to the actual sound sources used in experiment 1, and the carrier was pink noise. Absolute magnitude estimation was used for making judgments. Eight German subjects and eight Japanese subjects participated. Judgments of loudness, noisiness and annoyance were made for actual and for simulated sounds. Results showed the following. (1) The concepts “loudness”, “noisiness” and “annoyance” have rather different implications; various factors, such as the temporal pattern of the stimulus, frequency components, duration and subjective meaning, contribute to the differences. (2) Differences in the subjective meaning of sounds may have an important effect on judgments of noisiness and annoyance. (3) German subjects seem to be more sensitive to level fluctuation; they tend to judge sound on the basis of its maximum level, whereas Japanese do so on the basis of its energy. (4) In the case of traffic noise, there was little difference in the evaluation of the three aspects by the German and Japanese subjects; it therefore seems appropriate to evaluate these sounds by LA eq.

On the noisiness of steady state and intermittent noises

Abstract An experiment was designed to investigate the effects of sound level (LA), number of single noises (N), level of total energy (LT) and mean energy level ( dB(A) ) on the noisiness of steady state and intermittent noises. With the level and duration of pink noise controlled with a sound system called “Programmable Sound Control System”, 16 kinds of intermittent noises and 22 kinds of steady state noises were prepared. Seven subjects judged the noisiness of these stimuli by magnitude estimation. Their judgments were converted into the corresponding sound level (point of subjective equality, abbreviated PSE) by using the power function obtained between sound level and magnitude estimation for the seven kinds of steady state noises. As a result, the level of total energy and mean energy level were found inappropriate to evaluate the noisiness of intermittent noises though they showed high correlation with the noisiness of steady state noises. PSEs of the intermittent noises showed good correspondence with LN, which is expressed by the equation L N = dB(A) + 10 log N . LN could also be applied to steady state noises if it was assumed that a steady state noise with a duration of DT is equal to a 2000 ms noise presented N ( D T 2000 ) times. This result suggests that LN is a good measure of the noisiness of both steady state and intermittent noises.

Emotional expression of noise: A cross-cultural study

Abstract In our cross-cultural study of noise problems, the connotative meaning of the concepts of “loudness”, “noisiness” and “annoyance” were examined by using semantic differential in five countries. All concepts, except for loudness in Japan and China, were found to have negative images. Japanese and Chinese loudness were judged as neutral. In the present study, emotional expressions of various noises were examined by using the method of selected description in five countries—Japan, Sweden, West Germany, China and the U.S.A. Subjects were asked to select the adjectives which they thought appropriate for expressing their impression of each noise. On the basis of the adjectives selected and cluster analysis, it was found that “loud” in Japan, Sweden and China has neutral connotations, while “loud” in Germany and the U.S.A. has negative connotations. It was also suggested that “noisy” and “annoying” are not differentiated in Japan, while in the other four countries these two adjectives are used in different ways.

Social survey on wind turbine noise in Japan

Wind power generation is a promising means of utilizing renewable natural sources. However, sometimes the sound from wind turbine generators causes noise problems. A committee of Research on the Evaluation of Human Impact of Low Frequency Noise from Wind Turbine Generators conducted a series of physical measurements, laboratory psychological experiments and social surveys of wind turbine noise under the auspices of the Ministry of the Environment of Japan. Among the series of studies in this project, the study of social survey is introduced in this paper. A social survey was conducted at 34 sites where there were wind turbine generators nearby (wind turbine sites) and at 16 sites where there was no effect of wind turbine generators (control sites) across Japan from Hokkaido to Okinawa Prefecture. The numbers of respondents were 747 and 332, respectively. The design of the questionnaire used in the survey and the results, including a comparison between the wind turbine sites and control sites and the exposure-response relationship of annoyance, sleep disturbance and health status in relation to wind turbine noise, are discussed.

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.

Evaluation of aircraft noise : effects of number of flyovers

Abstract The subjective impression of aircraft noises when they overlapped various noises was investigated. Instantaneous noisiness was judged using the ‘method of continuous judgment by category’ developed by the present authors and compared with overall noisiness and physical values. The results were: (1) If other conditions are equal, the number of flyovers can be expressed by adding 10 log N to L a eq,30min , where N is the number of events and L a eq,30min is the equivalent continuous A-weighted sound pressure level. (2) The increase in noisiness produced by the overlap of aircraft noise depends on the level of background noise. An increase in the level of background noise by about 8 dB decreases the noisiness of aircraft noise by one category. (3) Overall noisiness depends on the total energy of environmental noise. From a statistical point of view, an increase by 1 dB can be significant in the category scale.

Exposure-response relationship of wind turbine noise with self-reported symptoms of sleep and health problems: A nationwide socioacoustic survey in Japan

The association of wind turbine noise (WTN) with sleep and physical/mental health has not been fully investigated. To investigate the relationship of WTN with the prevalence of self-reported symptoms of sleep and health problems, a socioacoustic survey of 1079 adult residents was conducted throughout Japan (2010-2012): 747 in 34 areas surrounding wind turbine plants and 332 in 16 control areas. During face-to-face interviews, the respondents were not informed of the purpose of the survey. Questions on symptoms such as sleeplessness and physical/mental complaints were asked without specifying reasons. Insomnia was defined as having one or any combination of the following that occurs three or more times a week and bothers a respondent: Difficulty initiating sleep, difficulty maintaining sleep, premature morning awakening, and feeling of light overnight sleep. Poor health was defined as having high scores for health complaints, as determined using the Total Health Index, exceeding the criteria proposed by the authors of the index. The noise descriptor for WTN was LAeq,n outdoor, estimated from the results of actual measurement at some locations in each site. Multiple logistic analysis was applied to the LAeq,n and insomnia or poor health. The odds ratio (OR) of insomnia was significantly higher when the noise exposure level exceeded 40 dB, whereas the self-reported sensitivity to noise and visual annoyance with wind turbines were also independently associated with insomnia. OR of poor health was not significant for noise exposure, but significant for noise sensitivity and visual annoyance. The above two moderators appear to indicate the features of respondents who are sensitive to stimuli or changes in their homeostasis.

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.

Impression of smoothness of a sound stream in relation to legato in musical performance

Physically continuous sounds do not always produce the subjective impression of legato. In the present study, the effect of temporal factors on the impression of smoothness of a sound stream was systematically investigated in relation to the dynamic characteristics of hearing. The results showed that decaying sounds, successively presented, were perceived as being marginally connected when the sounds physically overlapped, while steady-state sounds were perceived as being marginally connected when they were physically separated. It was also shown that judgments by the subjects agreed quite well with the effect intended by the pianist when the passage was given in different temporal interpretations.