ACS Articles - Is It Loud Enough?

Is It Loud Enough?

Why do some people like very loud music? You know the kind–you’re sitting at a stoplight when you feel a strange rumbling. A car pulls up next to you. All of your windows are closed, yet you can hear the music just fine. In fact, it’s so loud, everything in your rear-view mirror is vibrating to the beat!

Music affects our emotions. The notes, the instruments, the people singing, and the words they sing. Not only that, but the volume of the music affects us, too.

An article by David Clark in the spring 1995 issue of Professional Sound has the following to say about loud sounds.

"It turns out that loud sounds directly affect our autonomic nervous system (also called involuntary--it controls the body functions that you hope never stop, like breathing and digestion), in a way similar to many stimulent drugs. Adrenaline is released, the heart rate speeds up, the guts tighten up and move. This is the rush you get from loud music--it's real and it's beyond your conscious control. Sounds addicting, doesn’t it?"

As a sound engineer, you must resist the urge to push the fader up "just one more notch." You control the volume level the congregation is exposed to. If you can hear it, it doesn't need to be any louder

Volume (or loudness) is actually the sound pressure level, or SPL. Sound pressure levels are described using decibels. In the next column is a listing of decibel levels of common sounds and noises.

dB

0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
145
170
200

threshold of hearing
rustling leaves
very soft whisper at 1 ft.
soft whisper at 5 ft.
normal house
light traffic at 100 ft.
normal speech at 3 ft.
hair drier
noisy restaurant
train whistle at 500 ft.
elevated train overhead
discomfort, boiler factory
nightclub dance music at 10 ft.
threshold of pain
firecracker
one time may cause permanant hearing loss
jet engine
sonic boom when plane is 1000 ft. overhead

The decibel scale is based on a logarithmic equation (similar to the Richter scale for measuring earthquakes). If a sound source increases by 6dB, it has twice the SPL (sound pressure level). For us to actually perceive a sound to be twice as loud, it needs to be increased by 10dB. That means that a 12dB increase is four times higher SPL, but we perceive it only a little more than twice as loud.

The National Institute for Occupational Safety and Health (NIOSH) is part of the Centers for Disease Control in the United States federal department of Health and Human Services. They publish information regarding noise-induced hearing loss. Although aimed primarily at the construction industry, this information applies to any exposure of sound which can produce noise-induced hearing loss.

The chart below provides their maximum daily exposure figures.

SPL in DbA Maximum Daily Exposure

85
88
91
94
97
100
103
106

8 hours
4 hours
2 hours
1 hour
30 minutes
15 minutes
7.5 minutes
3.75 minutes

Here's a terrific chart from NIOSH (National Institute for Occupational Safety and Health) showing the relative levels of sound.

Many churches today not only reach sound levels of 100dBA or higher, some even STRIVE to reach such numbers - feeling this is what the congregation wants or needs. Other churches have implemented a decision on the maximum level allowed for normal services and events.

It's very easy to get caught up in the moment and keep pushing those fader levels higher and higher. Exposure to loud sounds breaks down your ears. They become less sensitive. When they become less sensitive, you need a higher SPL to hear, so you turn up the volume even higher.

God gave each of us only two ears. If we ruin them, we don't get new ones. Take care of your ears and the ears of your congregational. If you can hear it, it doesn't need to be any louder.

Suggestion: Use ear protection like ear muffs or plugs when using power tools or when you're in a very noisy environment. Your ears will thank you.