Hearing is Priceless ­ How Loud is Too Loud!?!

by Curt Taipale

 

Did we both go to the same concert? My wife and I went to a Michael W. Smith concert a few years ago, and ended up sitting in the far left side of the center section, roughly 80 feet back from the left speaker stacks. We left before the encore because I just couldn't stand it. Now, before you chuckle about my inability to stand loud sound, please realize that I've made my living as a recording and sound reinforcement engineer since 1980, and before that as a professional musician in rock & roll bands. If I couldn't stand it, it was loud!

How hard your ears are hit by the sound system can depend on where you're sitting. We saw Amy Grant in December '88, and this time sat about ten rows from the stage, almost dead center to the stage. The sound was glorious, and of course never got too loud. Why? We were too far out of the coverage pattern of the horns in the side speaker stacks to get hit like we did at Michael's concert. Anymore, we just don't go to concerts. There's too much at stake for me to go and enjoy a typical contemporary Christian music concert, so we just don't go. I miss it. But I can't afford to go.

The one thing that really got under my skin at the Michael W. Smith concert where my ears were starting to hurt occurred two rows in front of us. Hopefully I've forgiven the guy because I sure can't forget it. Here sat a nice Christian family, mom, dad, teenage daughter and young son, not more than 3 years old. Mom, dad and the daughter were up and bopping to the music. But this little boy was tucked into a ball in his seat, trying desperately to cover his ears with his hands. Occasionally the dad would pick him up and try to pry his tiny hands from his ears and get him to enjoy the music, but the kid just kept screaming the entire time that the sound was loud. During quieter songs, the boy was also quiet. The thought occurred to me that probably what was happening here was that mom and dad were trying to show their daughter and everyone else around how cool they could be, that they could still bop with the rest of them, and never even realized that their poor son was in excruciating pain the entire time. I wanted to punch the guy's lights out and rescue the kid. This little 3 year old had more sense than the combined intelligence of the other 2,000 people attending the concert.

You can do a lot to educate yourself about sound pressure levels in your own environment. Just go out to Radio Shack and purchase their little $29.95 Sound Level Meter. That's inexpensive enough for every church to have one and it's actually fairly accurate. With a little time and practice, you'll start to get a feel for what's what. Sometimes I even carry it into other churches when I'm there for a visit. It can be a little unnerving for the staff. I'm just being curious, and wanting to educate myself, and they're wondering what I'm up to. That's kind of funny when you think about it. I remember visiting a friend's church a couple of years ago. He was mixing the sound so loud that I just had to find out what the level was. We were on our way back from teaching a Soundcheck workshop, so I happened to have the meter with me. As discretely as I possibly could, I did a quick survey of the room. I measured 115 dB SPL during worship at the middle of the room. Jeanna and I looked at each other, and made a quick dart for shelter at the back of the auditorium. When I saw my friend at the close of the service, the ushers had already told him that "some guy is running around here with a sound level meter!" He knew it had to be me.

I've been in churches where the music director "required" average sound pressure level readings of 105 dB SPL during their regular worship services, and I've been in churches where a peak of 90 dB SPL sent people scurrying toward the sound booth. People are different, and every church is different.

I was on staff as the Audio Director for a large church for eight years. I always had my trusty little Radio Shack SPL meter sitting right in front of me. I tried to balance how "exciting" the music got and how loud I wanted it to be with what that meter was telling me. I knew, for that audience, that if I allowed the sound to go much beyond 92 dB SPL ('A' weighted) or roughly 95 dB SPL ('C' scale) that I would start to get complaints. The church had a tear-off "tab" in the weekly bulletin that provided an efficient means through which the congregation could communicate with the church staff. If there were complaints about the sound, I heard about it. If it was one or two complaints, we took note of it. If there were several comments, we did something about it ­ meaning, we would turn it down a notch.

Now for your audience, 92 dB might be way out of line. You might find it necessary to keep the sound back down to 85 dB during worship. If you can do that successfully, I would encourage you to do so. One rule of thumb says that if you have to raise your voice to communicate clearly to someone standing next to you, you're already in a noise hazardous environment. My ear doctor gave me a stern talking to when I told him that I regularly expose myself and our congregation to levels above 90 dB SPL. Since then, I have made a conscious effort to keep the level in check.

How loud things get also depends greatly on the type of music being played and how much control the engineer has over it. Soft, sparse ballads are a piece of cake. Christian rock & roll is almost impossible to keep soft. There's also the open stage monitor dilemma. Vocalists and band members continue to ask for their monitors to be louder. It gets so out of control that the audience begins to hear more of the stage monitors than the house speaker system. Out of control describes it well, because the desires and imagined needs of the worship team has gone beyond realities of their facility and sound equipment. Somehow it's all the sound man's fault, and he should be able to twiddle some secret knob and make it all go away. NOT!

It's clearly a challenge to make contemporary Christian music sound big and full and still not so loud that it becomes a distraction or a bother to a majority of the audience. How do you allow it to have the same kind of authority in a live setting as it has when heard on the original CD? One help would be to remember the Fletcher-Munson Equal Loudness Contours.

The Equal Loudness Contours reveal the average human hearing sensitivity at frequencies in the human hearing range over various listening volumes. They were determined something like this: The researchers would play a reference tone at, for example, 1 kHz, at a designated sound volume. They would then play a different frequency, adjust the volume and ask the listener to indicate when the new frequency sounded like it was at the same volume as the original frequency. They continued this process through several frequencies to come up with a "contour" of human hearing sensitivity at that one reference sound volume, say at 80 dB SPL. Next they would change to a reference volume of 85 dB, and repeat the process.

They averaged this data over several listeners to come up with their published Equal Loudness Contours. Part of what they discovered is that human hearing is most sensitive to sounds at around 3 kHz. At very soft listening levels, our hearing is least sensitive to very low frequency sounds, and slightly less sensitive to high frequency sounds. This is why there is a "Loudness" switch on your home stereo. You'll notice that when you switch it on, the sound gets a huge boost in the low frequencies, and also gets at little brighter. This is really just a special equalizer circuit tailored to counteract our hearing "deficiencies" at soft listening levels. At very loud listening levels, the contours start to flatten out, so the theory is that you would switch the Loudness circuit off when listening at elevated volumes. I know, I've turned it up loud with the loudness switch still turned on too.

Now, I figure that God didn't really build a deficiency into our hearing. I'm not really sure why it's that way. Maybe someday I will. But I do know that, when I'm trying to mix a "big" song at a soft volume, it helps the authority factor if, for example, I boost the bass guitar a little more than usual. Maybe I'll boost the kick drum slightly, or the low end piano mic. I would not go for the house system equalizer and offset it for this curve. That would cause more grief in other areas than it would help in this. But subtle adjustments to the mix of various instruments, or maybe a slight lift in the low frequency EQ on those channels, can provide a significant improvement to the sound. It won't solve everything. Louder will still sound bigger. But it may be the better compromise. If your sound system includes subwoofers, it can prove even easier to give your music that "authority".

Recording engineers have known about the equal loudness contours for years. Studies show that the average home stereo listening volume is 85 dB SPL. So the smart engineer will try to keep his mixing volume at around that volume. He will check it at very, very soft volumes, and he will turn it up loud and check it there as well. If the producer wants to hear it really loud, the really smart engineer will show the producer where the volume control is and leave the room. If this policy of mixing at 85 dB is followed, when you play it softer it should still sound fine. When it's played really loud, it should sound huge, bigger than life. If, on the other hand, the engineer mixes the songs at loud listening volumes, and then tries to listen to them at a soft volume, the resulting sound will not have the same punch. This isn't because of hearing fatigue. You'll still hear the same lackluster mix tomorrow after your ears have rested. Mixing at loud volumes alters both the EQ decisions as well as mix choices that the engineer makes. Those are based on what he's hearing at the time.

Do you remember when rock bands started turning the sound up louder and louder? Legend goes that it was back in the days of Grand Funk Railroad. I remember hearing a story about their manager. He discovered that whenever he had the sound engineer turn the sound up really loud, the kids in attendance would leave the concert in a state of euphoria. It's not that the music was so spiritually uplifting. It was a physiological state of euphoria caused by the sheer sound volume hitting their bodies for an extended period of time. There are many churches today who exceed the level of those early rock concerts every week in their regular worship service. Now, you tell me. Is the modern, loud church doing anything different?

Jimmy Swaggart's sound engineer once told me that they were feeding more power to Jimmy's stage monitors than they used to feed the entire crusade seating area. How long will his hearing be intact? How long will your hearing be intact? How about the hearing of those in your congregation? My suggestion for those of us who have been guilty of pushing the envelope is to repent, to ask God's forgiveness for not being good stewards of our own vessels and those around us, to plant one of those SPL meters right in front of the sound engineer, and to use your common sense from this day forward.

Do educate yourself about hearing. For example, did you know that everyone's sensitivity to loud sounds is different? In your discussions with people in your church, I'm sure that some of those people think the worship service is too loud, some think it's just right, and others think it's too soft. Why? Sure, some people complain because they grew up in a culture that didn't embrace loud music, so they're not used to it. Others like it loud. Part of the problem is that, since we all have a slightly different sensitivity to sound, everyone has a different definition of what "loud" means. Here's a scary one. Did you know that about 2% of the population has hearing that is so sensitive that they stand to lose their hearing totally and permanently if they are exposed to even a moment of sound that is beyond a certain sound pressure level!?! It will be gone in an instant.

Remember, hearing is priceless. So get HIP! It's your hearing! If you'd like to know more about hearing protection, we recommend that you contact the House Ear Institute (2100 West Third Street, Fifth Floor, Los Angeles, CA 90057, (213) 483-4431). Their website is http://www.hei.org. They have a great videotape and other materials that you could use to educate the powers that be in your own church. Another group is HEAR (Hearing Education and Awareness for Rockers), P.O. Box 460847, San Francisco, CA 94146, (415) 773-9590. Their website is http://www.hearnet.com.

Copyright 1997. Taipale Media Systems, Inc. All Rights Reserved

After making his living as a professional musician for twelve years, Curt Taipale returned to college and earned his Bachelor of Music degree from the University of Miami in 1980. He has invested his career ever since as a recording and live sound engineer, a consultant, educator, and author. He served ten years on full time church production staff plus many more years as a guest sound engineer. He contributed three chapters to the Yamaha Guide to Sound Systems for Worship, has written numerous articles for several magazines, and is the Church Editor for Live Sound International. To learn more about Curt's background, see Who Are We?

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