I can tell you from experience that just one concert, a lot shorter than eight hours, can easily provide permanent hearing damage. Some years ago, I walked out of a concert with tinnitus and I was wearing hearing protection for most of it. Every single professional musician I know has hearing loss and/or tinnitus and remember that on stage, they're not even getting the brunt of the sound because the sound system is in front of them. They have their own monitors and more and more, artists use in-ear monitors to protect their hearing.
From an aesthetic standpoint, when actors are talking normally on the screen, it should not sound like they're screaming at you and it should not cause discomfort. There's a difference between room-filling sound plus great dynamic range (for blasts, etc.) and films in which is the sound is highly compressed and presented at very high levels for the duration, usually because directors are insecure about their films and believe that jacking up SPL's creates excitement or emotion, but it doesn't - it just creates fatigue.
The problem in the theater is that the levels might be set for a full crowd wearing coats on a Saturday night, but when there's only a few people in the auditorium, there's nothing to absorb the sound.
An example of the great use of dynamic range was in the original 70mm release of "Close Encounters..." In the theater and even though this was before split surround, near the end of the film when the glass breaks in the viewing tower, it appeared to come from the right rear of the theater. The sound was so loud, but so realistic, everyone turned their heads because we thought something actually crashed in the theater. (It's not mixed that way on the Blu-ray and it wasn't mixed that way when the film was shown digitally via DCP some years ago.).
Furthermore, there was an article published in EQ magazine in September of 2002, listing OSHA sound levels and the time of maximum exposure. One could listen to loud street traffic with an SPL level of 85db (A-weighted) for 8 hours, but anything louder than that had reduced times before one could expect hearing damage:
Loud classical music: 97db (47 minutes, 37 seconds)
Subway passing; 103db (7.5 minutes)
Thunder: 110db (1.5 minutes)
Loud rock close to or on stage: 115db (28 seconds)
Jet takeoff from 200' away: 125db (3 seconds)
Threshold of pain: 130db and higher (zero seconds)
I have measured peaks of 125db in movie theaters. I can't say with exactitude how long they lasted, but even relatively short blasts at that level is unnecessary and in addition to the problem of level, it's usually highly distorted.
But max levels before hearing damage is not even the point. Film mixers and movie theaters should not be setting sound levels based on the maximum before hearing damage - they should be setting level based upon what sounds good. And as an ex-recording engineer, it's my opinion that levels today are absurdly loud in too many instances and it's not just clubs and rock concerts - it's also some Broadway shows and movie theaters, especially the trailers. I think it's ridiculous that if I'm going to see an action movie that I have to remember to bring hearing protection with me. Great sound doesn't have to be over-loud - it just has to be room filling and properly frequency balanced with a great high-end frequency response, tight bass and dialog clarity, but with resonance. It should not sound metallic or brittle and in too many theaters it does, and when such sound is played at high levels, it's really awful.
From an aesthetic standpoint, when actors are talking normally on the screen, it should not sound like they're screaming at you and it should not cause discomfort. There's a difference between room-filling sound plus great dynamic range (for blasts, etc.) and films in which is the sound is highly compressed and presented at very high levels for the duration, usually because directors are insecure about their films and believe that jacking up SPL's creates excitement or emotion, but it doesn't - it just creates fatigue.
The problem in the theater is that the levels might be set for a full crowd wearing coats on a Saturday night, but when there's only a few people in the auditorium, there's nothing to absorb the sound.
An example of the great use of dynamic range was in the original 70mm release of "Close Encounters..." In the theater and even though this was before split surround, near the end of the film when the glass breaks in the viewing tower, it appeared to come from the right rear of the theater. The sound was so loud, but so realistic, everyone turned their heads because we thought something actually crashed in the theater. (It's not mixed that way on the Blu-ray and it wasn't mixed that way when the film was shown digitally via DCP some years ago.).
Furthermore, there was an article published in EQ magazine in September of 2002, listing OSHA sound levels and the time of maximum exposure. One could listen to loud street traffic with an SPL level of 85db (A-weighted) for 8 hours, but anything louder than that had reduced times before one could expect hearing damage:
Loud classical music: 97db (47 minutes, 37 seconds)
Subway passing; 103db (7.5 minutes)
Thunder: 110db (1.5 minutes)
Loud rock close to or on stage: 115db (28 seconds)
Jet takeoff from 200' away: 125db (3 seconds)
Threshold of pain: 130db and higher (zero seconds)
I have measured peaks of 125db in movie theaters. I can't say with exactitude how long they lasted, but even relatively short blasts at that level is unnecessary and in addition to the problem of level, it's usually highly distorted.
But max levels before hearing damage is not even the point. Film mixers and movie theaters should not be setting sound levels based on the maximum before hearing damage - they should be setting level based upon what sounds good. And as an ex-recording engineer, it's my opinion that levels today are absurdly loud in too many instances and it's not just clubs and rock concerts - it's also some Broadway shows and movie theaters, especially the trailers. I think it's ridiculous that if I'm going to see an action movie that I have to remember to bring hearing protection with me. Great sound doesn't have to be over-loud - it just has to be room filling and properly frequency balanced with a great high-end frequency response, tight bass and dialog clarity, but with resonance. It should not sound metallic or brittle and in too many theaters it does, and when such sound is played at high levels, it's really awful.
Comment