A video recently resurfaced showing a car sound system powerful enough to blow off snow from the vehicle. As the bass line kicks in, the car starts to shake from the low frequency vibrations. The snow on the windows falls off instantly while the layer on the roof keeps spilling off the edges.
While many viewers expressed astonishment as to how far the owner was willing to take his sound system, many comments were disapproving—at the end of the video, a young boy is seen in the car covering his ears.
Some were of the opinion that it’s inappropriate to comment on other people’s parenting. After all, the boy was smiling and presumably could leave the car if he didn’t like it.
Some also suggested that low frequency sound doesn’t hurt hearing.
Others thought the sound was loud enough to hurt the boy or at least contribute to hearing problems in the future.
To date, there isn’t much research done specifically on the effects of low frequency sound on hearing.
“Generally noise-induced hearing loss occurs at a pitch of about 2000-4000 Hz,” states The American Hearing Research Foundation.
But just because people usually lose the ability to hear high frequencies (2000-4000 Hz), it doesn’t mean low frequency sound doesn’t damage hearing.
“The frequency of the sound is less important than its decibel level and time of exposure,” according to the Dangerous Decibels, a public health campaign directed by University of Northern Colorado audiology professor Deanna Meinke and National University of Singapore public health and preventive medicine professor Billy Hal Martin.
Decibel levels describe how loud the sound is.
30dB is a person whispering.
60dB is a normal conversation.
80dB is busy traffic.
100dB is a pneumatic drill only a few feet away.
105dB is an MP3 player at maximum volume.
115bB is a loud rock concert (but not too close to the speakers).
125dB is the pain threshold.
140dB is a jet engine 100 feet away.
165dB is a 12 gauge shotgun blast
Listening to 70dB—your music player at about half the volume—should be no issue at all. Crank it up to 90dB—your music player at 80 percent volume—and experts recommend a maximum of 90 minutes exposure. Any higher than that and you should quit in just a matter of minutes.
What’s important to understand, decibel is a logarithmic unit. In this case it means every 10dB increase translates to sound perceived as twice as loud.
But the sub-woofer enthusiasts can at least partially rejoice. Low-frequency noise is considered to cause less hearing damage. The pain threshold for 50 Hz sound (just a bit lower than what you can hear in the video) is 135dB.
Still, very loud (120dB) low frequency noise has caused hearing loss in laboratory animals and temporary hearing loss in humans.
“There is an indication that long-term exposure to very high levels may cause permanent hearing loss,” states a 2003 paper on the subject.