Annoyance caused by simultaneous impulse, road-traffic, and aircraft sounds: A quantitative model

Abstract

In this study, total annoyance caused by different simultaneous environmental sounds is investigated. In spite of a number of puzzling data in the literature, it is fairly well established that in combinations in which the annoyance of one source is considerably higher than that of another source, total annoyance is equal to the maximum annoyance of the separate sources. For combinations in which both sounds are about equally annoying, total annoyance seems to be higher than the maximum source-specific annoyance. The available data, however, are too rough to model total annoyance in these conditions. The present laboratory studies were therefore designed to explore further possible procedures to quantify total annoyance. Subjects rated the (total) annoyance caused by various combinations of impulse, road-traffic, and aircraft sounds. The results support a simple model which predicts the overall or total rating sound level L(t) for combinations of several types of sounds. Here, L(t) is numerically equal to the A-weighted equivalent sound level L(eq) of road-traffic sound with the same annoyance as caused by the combination of sounds. In the model, the sound exposure caused by the impulse and/or aircraft sounds is first expressed in the L(eq) of equally annoying road-traffic sound. With the help of source-specific dose-effect relationships, this is achieved by adding level-dependent penalties to the L(eq) of the respective sources. Weighted summation of the corrected L(eq)'s of the various sources then results in L(t). An optimal overall fit of the data from two separate experiments was obtained when the weighted summation of the corrected L(eq)'s was performed with the parameter k in k log(sigma 10(corrected L(eq) of source j)/k) set to 15. The standard deviation of the differences between the experimental results and the model predictions with k = 15 was equivalent to the small change in annoyance produced by a 1.5-dB shift in the L(eq) of road-traffic sound. Adoption of k = 15 implies that after correction, two equal L(eq)'s yield a total rating sound level which is 4.5 dB higher than each single-source corrected L(eq).

On the level-dependent penalty for impulse sound

“…The degree to which the penalty for G relative to T, as found in this study, decreases with the level of G is smaller than that found in previous studies in which the G and T sounds were presented in a quiet or a 30 dB (A) background (Brambilla and Carretti, 1989;Flindell and Rice, 1986;Rice, 1983;Vos, 1989;Vos and Smoorenburg, 1983), but comparable to that found for G and T sounds in a low background noise of 35 dB(A) (Vos and Smoorenburg, 1985). The absolute value of the penalty obtained in this study, however, is on the average about 4 dB lower than it was in the six studies mentioned above, which was unexpected.…”

“…For the studies in which the background noise was held as low as possible, the average results showed that this penalty ranges from about 10 dB at an impulse Leq of 35 dB(A) to about 0 dB at an impulse Lcq of 65 dB(A), all levels measured indoors (Brambilla and Carretti, 1989;• Flindell and Rice, 1986;Rice, 1983;Vos and Smoorenburg, 1983). A similar 10-dB decrease of the penalty for gunfire sounds over a 30-dB stimulus range was found in an experiment in which a continuously present background noise at an Lcq of 30 dB(A) was added (Vos, 1989). In related experiments of Vos and Smoorenburg (1985) in which the sounds were presented against a background noise of 35 dB (A), the penalty ranged from 12 dB at an impulse Lcq of 35 dB(A) to the 5-dB penalty recommended by ISO/R 1996ISO/R ( 1971 quence of the use of the ten-point rating scale (ceiling effect in some conditions with high Leq-values?).…”

Predictive Model of Annoyance Induced by Combined Transportation Noise

“…Fig.6. shows that the annoyance from two combined sounds is higher than that for a single sound, which was shown in the research of Vos (1992) 7 . Fig.7.…”

“…This model uses two variables with the continuous sound level of combined sources and the absolute difference between the sound levels for the separate sources. Kryter 6 , Vos 7 , Miedema et al 8 and Miedema 9 applied the percentage of highly annoyed respondents (%HA) as a parameter in their research on the relationship between annoyance and physical measures. Vos proposed a model to predict total annoyance for mixed noise using experimental impulse, road traffic, and aircraft sounds, and concluded that the total annoyance is equal to the maximum annoyance induced by the separate sources.…”

Environmental sound research as it stands today

“…In the medical fields, research has been directed primarily at restoring the ability to perceive the world through sound by the hearing impaired and development of novel diagnostic methods. Subjective evaluations of environmental sounds and their contributions to the annoyance in specific environments have been the subjects of noise control research [71][72][73][74][75]. Experimental results regarding the effects of various types of sounds in the listeners' environment on communication and productivity have lead to efforts to develop a conceptual framework for designing listening environments or soundscapes [76].…”