Ask people about the volume level in movie theaters, and you'll get an earful.
Here are some reactions I received when I asked the Tribune's Twitter followers to relay their experiences about noise in movie theaters:
• "I was at [one theater] a couple of weeks ago and the previews almost killed my ears it was painful."
• "My wife always cracks 'Nigel got a job as a projectionist.' " [Presumably, this is a reference to Nigel Tufnel of Spinal Tap, whose amp goes to 11.]
• "Just ask the parent of any autistic child that goes to a movie with fireworks in it."
• "I had that problem all of the time when I lived in [Utah]. I figured it was to compensate for the rude audiences."
In a highly unscientific study, I took a sound level meter into six auditoriums at two major Salt Lake Valley multiplexes. (The theaters will remain unnamed, because the issue isn't limited to any one theater or chain.)
What I found was that for many movies, noise levels aren't so bad.
For children's movies and comedies, the needle usually stayed in the range of 80 decibels — though a few trailers for kids' movies did spike up to 90 decibels. For the most part, the trailers weren't louder than the movies — but they hit the peak level more often than the movies did.
It's when I went into a theater playing an action movie where the needle started dancing, staying around 90 decibels during the more intense action sequences.
And during the trailers before the action movie, the meter momentarily went up to 100 dBs — the loudness of a motorcycle engine revving right next to you.
"In general, the Hollywood releases tend to peak in our theater somewhere around 100 and 105 decibels," said Richard Cox, information systems manager for the Clark Planetarium — and the man who operates the downtown Salt Lake City facility's ATK IMAX Theatre (which was not one of the theaters I tested).
"There are a lot more explosions, a lot more car crashes — a lot more action in movies these days than there used to be," he said.
Cox said the planetarium started getting complaints from patrons about the sound in the fall of 2010, when the ATK IMAX started screening Hollywood releases — the first was "Harry Potter and the Deathly Hallows, Part 1." That also was the same time the theater got a new 14,000-watt sound system.
"I started lowering [the volume] a bit, and the complaints dropped off," Cox said, adding that he now regularly drops the volume about 5 decibels below the recommended level.
The good news for audience members is that while loud movies may be temporarily uncomfortable, the noise shouldn't do lasting damage to one's hearing.
"It's safe to listen to a certain level of music for a certain length of time," said Kevin Wilson, assistant professor of otolaryngology at the University of Utah.
Wilson points to OSHA workplace standards for noise — which say employees can work up to eight hours a day in an area where the noise is at 90 decibels, or two hours where it's up to 100 decibels, without sustaining permanent hearing loss.
There's another kind of hearing loss to consider, Wilson said: "temporary threshold shift," which happens when you hear a sharp, loud sound. Such a noise flattens the hair cells in the inner ear, where sounds are detected and transferred to the brain, causing a brief loss of hearing — sometimes described as a ringing in the ears.
It has been doctrine among the hearing-loss experts that "temporary threshold shift" caused no permanent damage to hearing. However, Wilson said, a recent study suggested that multiple instances — and it would take a lot of loud noises over a long period of time — can do lasting harm to one's hearing.
For some, though, the thrill of getting blasted into your foam-rubber seat is part of the fun of going to the movies.
Movie fans who have their own home theaters, Cox said, "need a reason to go to the theaters. You need an experience you're not going to get in your mancave."
