Friday, May 12, 2006

How Loud Is Too Loud? :|: The Science

Today's Topic: Questions & Answers

The major discussion on the ChurchSoundCheck email list this week was entitled: "Turn it Down." If you are a member of churchSoundcheck but haven't read the emails, sign in to the archives to read the posts. If you're not a member, consider signing up. The conversation started when this report came from Randy Goldman:
"A church in our community just had her Youth Minister arrested last Friday night. Seems an ongoing dispute with neighborhood residents about the volume has reached critical mass. One resident swore out a warrant for disturbing the peace, and the police, following procedure I'm sure, acted on it. The affidavit alleges the church played excessively loud music from 7 pm to 10 pm several nights a week."
The conversation covered several topics including being good witnesses to our neighbors, the importance of acoustics in sound separation, the legalities of this arrest, and others. The conversation also asked this very important question:

How Loud Is Too Loud?

With "contemporary" music as the standard fare of many worship teams, and with churches striving for relevance with young unbelievers, singing in church often resembles a rock concert more than a choir performance. As a result, the volume levels in churches do seem to be increasing overall.

This causes great concern among some people, including many that attend Covenant Life with me. Some complain it's too loud. Some wonder whether this will damage their hearing. Some want it turned up. I'm sure I'm not alone in this. How do tech team members respond to these various questions and concerns?

It can be difficult to answer people because they may say "it hurts" or "it's uncomfortable." They have concerns about their children or their elderly parents. Everybody is different both in their preferences and in their bodies, so how do we know if someone is really being hurt by our music?

First, let me say this: We must respond. We must have an answer for the people who are concerned, even if we can't explain it to them at the moment they ask. To simply shrug off these concerns is irresponsible, uncaring, and possibly even sinful. We will be held responsible by God for anything we knowingly do that hurts others.

I think the best way to answer these questions about safety is to point to the legal standards that government scientists have put into place. As you will see, this may make some people unhappy and others thrilled. But it's the most accurate and fair way to help lead our sound board ops as to how loud they should mix, without having to be swayed by the most recent complaint.

So, on to the question. How loud is too loud? Although there are many different scales out there for loudness levels, the legal limits are set by the Occupational Safety and Health Administration (OSHA). Check out their standards table. These standards reflect the maximum sound pressure level that a person can experience for a certain duration of time without noise-induced hearing loss, to the best of our knowledge.

Here is what I see when I read this table. Covenant Life attendees will sing for a maximum of 40 minutes at the beginning of our service and 10 minutes after, for a total of 50 minutes with the band. I'll round that up to an hour to be safe. According to the chart, a person can listen to music at a sound pressure level of 105 dBA without any expectation of noise-induced hearing loss.

Also, an important note is that dBA is a different scale than dBC. dBC is more sensitive, so if I run the system at 105 dBC, the sound pressure is actually less than 105 dBA. Therefore, our normal spl's of 95-98 dBC are well within the safe range for our church members.

However, we don't get off that easy. There will be people who attend more than one service. We have two services, and some servants (including the sound mixers and musicians) will be there for both. What about them?

To be safe, let's say the sound folks and the musicians are there for one hour of rehearsal and two services, each with one hour of singing. This is way over the actual time, but I'd rather be safe. For three hours total, what is the max sound pressure level? Around 97dBA. Again, our 95-98dBC levels are safe, but they are on the edge. I certainly don't want to go beyond this. And that really only applies for the sound mixers. The musicians are harder to judge, since they are under headphones and get to set their own overall levels.

Nevertheless, with this simple math complete, I can honestly answer people, regardless of their perception, that I believe our sound levels are reasonable and safe. Would you agree? Have I missed something?

Maybe more importantly, can you do the same? I challenge you this weekend to think through your sound pressure levels. Consider your service times, exposure durations and the different people who attend. Is anyone at risk of hearing loss? What do you need to do to change?

Unless I get other questions, I'll answer the more subjective side of the question, "How Loud is Too Loud?" next week Friday.
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Anonymous said...

Dave,thanks for serving folks with your biblical approach to these issues. I think it's important to, as you did, begin with attitudes and hearts, not laws.

I would like to add that it's important to be aware of the room you're in.

Many churches meet in multi-purpose rooms, gymnasiums, cafeterias, etc. For those folks, it's important to remember that different parts of the room will register sometimes significantly different levels. Based on this knowledge, you cna adjust your levels to meet biblical standards of care.

My $.02

Anonymous said...

I really enjoy your blog! Thanks for your honest heart and truthfulness, it is refreshing to hear someone be real. Its cool to read about real people who serve Jesus.

I am a musician, and I would be honored if you would check out my music. All music on my site is free for download. Anyway, don’t want to be a pest, I just thought that I’d share.

“All my music is free.”