Question
Are there laws or public safety recommendations regarding acceptable noise volume in public movie theaters?
Answer
The short answer is ''no, there are none...as far as I know''. And maybe I should add that I don't think there should be, based upon measures we've made at Central Institute for the Deaf (CID, St. Louis, MO). Unless, however, there is a synergistic interaction between noise and popcorn!
One of our graduate students, Julie Mullen, is carrying noise dosimeters to the movies this semester as part of her independent study project. She's attended about 10 movies so far, and our minute-by-minute analysis suggests that even though movies are certainly very loud, they do not approach levels that can be considered hazardous. In addition, since people are usually ''exposed'' to the volume in the theater for only one to two hours at a time, the individual's risk is more likely to be discomfort than damage.
One hypothesis we have is that movie producers put more compression into movies that are designed for older audiences. It just makes sense that the ''drama'' type movies that are targeted to older viewers may be quieter, and soft sounds might also be boosted to compensate for a reduced dynamic range in a listener with sensorineural hearing loss.
We're actually looking at the sound level distribution (L10-L90) range for all the movies we've recorded so far, and this idea seems to hold up so far. We're also looking across theaters to see if one chain is louder than another. I won't be able to answer that question right away, but it might make for follow-up questions later. One thing we know already is that the previews definitely are louder than most of the movies. So stay tuned, this research is ongoing!
BIO: Dr. William Clark is Director of Professional Education and a Senior Research Scientist at Central Institute for the Deaf in St. Louis, Missouri. He is also Chairman of the Department of Speech and Hearing at Washington University in St. Louis, where he holds the rank of Professor. His work on noise-induced hearing loss encompasses laboratory studies of exposure in animal subjects, and field surveys of exposure and hearing loss both within and outside the workplace. Dr. Clark has published over 80 papers on the effects of noise on hearing. Dr. Clark's work is well known to professional and lay audiences. His studies of leisure noise exposure have been featured on ABC's ''20/20'' news program, and he is frequently quoted in national media coverage about noise.