Q: Are you familiar with the effects of noise on public health?
Ans: Yes. In addition to my work with the U. S. EPA, I have attended and made presentations to numerous International Congresses on Noise as a Public Health Problem. They include 1968 (Washington, D.C.); 1973 (Dubrovnic, Yugoslavia); 1978 (Friburg, Germany) and 1982 (Turin, Italy). These were gatherings of active researchers on the topic from around the world. Proceedings of the Congresses were produced and are contained in my library.
Q: Could you describe some of these effects?
Ans: Yes. The effects include loss of sleep, hearing damage, irritability, exacerbation of nervous and cardiovascular disorders, and frustration stemming from loss of control of one’s acoustical environment.
Q: Is a person able to control the physical reaction within their body to sound?
Ans: Only to a limited extent. Dr. Samuel Rosen, formerly physician at New York City’s Mt. Sinai Hospital stated: “You may be able to ignore noise – but your body will never forgive you.” The truth in this statement is that “coping” is a fatiguing activity. Therefore, the energy spent in coping with environmental noise or the frustrations it produces, is robbed from energy desired for other forms of activity.
Q: At what sound levels would your expect to see reactions of effects of noise?
Ans: Surprisingly small sound levels can cause certain reactions. For example, sleep studies have shown that subjects will shift two or three levels of sleep when the environmental sound is increased only 5 dB. Thus, a person in the Rapid Eye Movement (REM), the fifth stage of sleep, when the bedroom sound level is 35 dBA, will shift out of that essential level of sleep when the sound increases only to about 40 dBA. As a result, this negative health effect is known to lead to chronic fatigue and irritability.
Q: Could you please explain the effect of noise at night in residential areas?
Ans: Yes, recall that I mentioned low-frequency noise entering a house almost unimpeded. If that noise source is the predominant sound in a bedroom, any change in the sound level can influence a person’s sleep level, therefore, reducing the adequacy of rest afforded by sleep. Further, the noise source, if it is from the power generation plant, serves as a masking noise. That is, it covers up other sounds to which one may need to attend. For example, sounds from a child’s bedroom.
Q: Could you please explain the effect of low frequency noise and how it travels?
Ans: Yes, but to do so, I must introduce the term “wave length”. This is the distance covered by a sound during one cycle. For example, a mid-frequency 1000 Hz sound has a wave length of slightly more than 1-foot. Lower frequency sounds have longer wave lengths. Thus, a 100 Hz sound has slightly more than a 10-foot wave length. The longer the wave length, the more efficient the sound is in penetrating barriers such as walls of a structure. For the purposes of this investigation, I would define low frequency sounds as those falling below 100 Hz. Perhaps you have experienced life in an apartment when a neighbor plays a stereo loudly. The sound that penetrated to your quarters was the bass (low frequency sound). Also due to the wave length characteristics, low frequency sounds dissipate less over distance than do sounds of higher frequency.
Download original document: “Prefiled testimony of David Lipscomb before Washington state EFSEC”, June 2004