Your ears can handle 85 dB of sound unprotected for up to 8 hours, but the length of time your ears can endure sound exceeding 85 dB without hearing protection decreases significantly with each increase of 3 dB of intensity.

Four hours of exposure to 88 dB can cause damage, while damage occurs after 2 hours at 91 dB and at 94 dB in 1 hour. If your unprotected ears are exposed to sounds in excess of 110 dB for more than 90 seconds, your ears experience severe damage, but it takes only 7 seconds to do harm to your unprotected ears at intensity levels of 120 dB.

For perspective, lawn equipment, chainsaws, motorcycles, snowmobiles, and power tools have noise levels of between 90 and 105 dB, which means that if you use them for more than 20 or 30 minutes, you should be using hearing protection to prevent damage. Listening to music on headphones or earbuds at high levels (110 to 115 dB) is particularly dangerous, as is a major sporting event, live concert, or a nightclub (up to 135 dB) while discharging a firearm can reach an intensity level in excess of 145 dB.