TABLE 5 Differences Between Controlled-Exposure and Social Survey Studies of Noise-Induced Annoyance

Factor

Controlled-Exposure Studies

Community Surveys

Customary goal

Determine perceptual function

Estimate opinions of population

Study design

Experimental (causal relationship between independent and dependent variables inferable in principle)

Observational (correlational evidence only, no strict inference of causality possible)

Sampling method

Self-selection

Variable; often random representation

Test participants

Paid test subjects providing informed consent

Neighborhood residents

Dependent variable (quantity judged)

Immediate, solicited judgments of short-term annoyance of temporally compressed presentations of novel signals during a test session of relatively short duration

Delayed, retrospective judgment of long-term annoyance of habitual exposure to familiar sounds occurring at times of day and intervals appropriate to their generating mechanisms

Basic datum

Relative frequency of occurrence of specific, solicited judgments

Prevalence among respondents of self-reports of annoyance in similar degrees

Data collection setting

Contrived (laboratory or modified residential) listening environment

Unmodified residential

Characterization of independent variable

Precise knowledge of signal characteristics, reasonable information about individual exposures

No control over noise exposure other than site selection; imprecise knowledge of place exposure, little or no knowledge of personal exposure

Low-frequency content of sounds judged

Often lacking in ability to accurately reproduce low-frequency content of high-energy impulsive sounds and/or secondary emissions

Appropriate to source and residential setting; no decorrelation of low-frequency content and absolute level of individual events



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement