Two studies examined effects of interventions to reduce noise levels from portable stereo headphones. Study 1 examined the effectiveness of warning signs posted in and nearby public elevators with 567 passengers possessing a portable headphone (total N = 7,811). During a 9-day baseline, the mean percentage of headphones played at an observer-audible level was 85%. During a subsequent 6-day warning sign phase, the mean percentage of audible headphones declined to 59%, which increased to a mean of 76% during a second baseline phase (5 days). Study 2 assessed the impact of a student confederate who lowered his or her observer-audible headphone volume at the polite request of a second student confederate. Of the 4,069 elevator passengers, 433 possessed a portable headset. The mean percentage of observer-audible headphones during a 4-day baseline was 85%. Subsequently, a 5-day modeling intervention reduced audible volumes to a mean of 46%. During a second baseline phase of 4 days, the mean level was 77%, and during reintroduction of the modeling phase (9 days) the mean level was 42%. The modeling intervention was significantly more effective with women (53% compliance) than men (29% compliance).DESCRIPTORS: audio headsets, signs, modeling, prevention, behavioral community psychology About 23 million portable stereo headset radios and tape players are sold annually in the United States (Monroe, 1990). In many densely populated urban areas, thousands of individuals use these headsets to mask the environmental sounds of city dwelling. Unfortunately, by using a personal stereo, especially if set at a high volume, an individual These studies were presented at the annual meeting of the Eastern Psychological Association, New York, April 1991. These data were collected when the first author was a Visiting Assistant Professor and the second author a B.A. Psychology major at Baruch College, CUNY.The authors thank Leonard Jason and several reviewers for comments on an earlier draft of this paper, and John Andreassi for use and instruction of the sound meter. The authors also thank the following undergraduates who volunteered as observers or models in either or both studies: Alexander Caraballo, Milagros Dueno, Candice Fant, Michael Kieran, Raymond Lo, Sara Morales, Sharon Parris, Marlene Saybe, Sharmilla Sheogobind, Suzanne Sommer, Amy Tran, and Jacinta Vermong. Also, thanks to Ximena Aguirre for designing and drawing the warning prompts used in Study 1, as well as participating as an observer.Correspondence should be addressed to Joseph R. (Lee, Senders, Gantz, & Otto, 1985;Rice, Rossi, & Olina, 1987;Rinntelmann & Peppard, 1983). Navarro (1990) examined 51 portable stereo headsets to determine whether they produced sufficient levels to damage hearing. Each headset was coupled to the artificial ear of a sound level meter and decibel (dB) levels were measured at three settings: one third full volume, two thirds full volume, and fill volume. Results showed that the headsets produced an average of 87 dB at one third volume, 100 d...