Movie theaters and decibels
steve at accessone.com
Mon Jul 21 08:00:24 EST 1997
The Screenplay May Not Move You, But the Sound Level Might
Wall Street Journal 7/21/97
The summer blockbusters are out: Loud and Louder. At least,
that's what impressed Sidney Russell of San Francisco about the
film "Batman & Robin." It wasn't about action or adventure. It
was about volume.
"It was extremely loud," says the 11-year-old. "It was almost
Movies shouldn't hurt your ears. But sophisticated audio
technology now enables soundtracks to be made, and played, at
roof-raising volumes without the fuzziness or distortion of the
past. Climactic scenes of summer blockbusters sometimes exceed
100 decibels -- the noise level generated by a riveting machine.
While many filmgoers relish a chair-rattling audio experience to
enhance the drama on screen, folks with sensitive ears may find
today's peak volumes physically uncomfortable or potentially
Ear-bludgeoning sound from feature films -- and even louder
blasts from trailers -- are capable of inducing headache,
tinnitus (ringing in the ears), or even temporary shifts in
hearing that could presage early damage. Moreover, high noise
levels can raise blood pressure, heart rate and stress hormones.
For this column, Robert Sweetow, audiology director at the
University of California at San Francisco, sampled sound levels
at San Francisco Bay Area theaters with a sound meter. While
decibel readings can vary widely based on theater acoustics,
audio equipment and volume settings, here's what he found:
"Batman & Robin" peaked at 112 decibels in one theater, while
"Contact" measured 107 decibels at another -- volumes equal to
those produced by a pneumatic hammer.
In the workplace, the federal Occupational Health and Safety
Administration limits allowable noise levels to 90 decibels for
an eight-hour day. Higher levels are allowed for shorter periods,
for example, 110 decibels for half an hour.
At play, however, consumers are on their own.
State-of-the-art sound gets star billing these days as movie
makers and theaters advertise digital soundtracks and audio
systems by Dolby Laboratories Inc., Sony Cinema Products Corp.
and Digital Theater Systems, which is partly owned by Universal
"They're pushing the envelope," says hearing specialist Robert
Schindler, chairman of otolaryngology at UCSF.
"The problem," acknowledges Dolby Laboratories President Bill
Jasper, "is that as we've developed digital technology, movie
makers have taken advantage to provide a real wallop to the
viewer. This can be disturbing."
This is especially true of coming attractions. "Studios want you
to remember theirs," he adds. "So there's a battle of the
At Sony Cinema Products Corp. Vice President Bill Mead concedes
"everybody agrees" trailers should be toned down. "But nobody
wants to be first to do it."
As for feature films, Messrs. Jasper and Mead say they don't
dictate how a movie sounds. Digital-sound companies offer
technical services to a movie's creative team, calibrating
soundtracks and suggesting sound levels for the theater.
But volumes are largely determined by local projectionists, who
may play films louder than is recommended, says Barry Reardon,
president of Warner's Distribution, a unit of Warner Bros.
Pictures, which created "Batman" and "Contact."
Mr. Reardon says he gets annoyed by preview trailers boomed at
"hot" decibel levels. "One trailer is played at normal levels and
another blasts you right out of your chair," he says. "I've gone
to theater managers and said 'Hey, you're playing that too loud.'
He says an industry task force of movie companies and theater
owners is trying to standardize -- and lower -- trailer volumes.
Audiences should applaud the effort. Dr. Schindler of UCSF says
the average filmgoer isn't hurt by volumes of 110 to 112
decibels, but he wonders, "Is it possible some members of the
public would sustain damage? Yes, it's possible."
AT THESE LEVELS, some people could walk out with temporary
alterations in their hearing lasting minutes or days, Dr. Sweetow
says. "Someone with a propensity to get tinnitus could get pushed
over the edge," he says.
Indeed, an explosive noise -- like the 140 decibel roar of a jet
engine -- can blow away the fragile hair cells in the inner ear,
destroying the ability to detect soft speech and high-frequency
sounds. And you won't always know when you're in danger.
"Auditory problems are insidious," says Dr. Sweetow. "You don't
realize when you're doing damage to your ears." One loud rock
concert can leave patients with permanent tinnitus, and legions
of frequent concertgoers now suffer high-frequency hearing loss.
He adds that people will say, "I can hear but I can't
understand." That's because consonant sounds are heard at the
high frequency range that gets damaged first.
Now that rock stars wear earplugs and personal stereos bear
volume warning labels, Dr. Schindler says it's time for the
entertainment industry to rate movies for sound intensity.
To protect your hearing, sound off when volume gets too loud.
Learn about a theater's sound system and select those offering
pleasurable audio experiences.
"If you're in a place where it's too loud, get out, plug your
ears or tell the operator," says Dr. Sweetow. Let them hear your
feedback for a change.
More information about the Audiolog