Noise levels

The volume - level of energy in the sound, measured in decibels. Whisper equates to 15 decibels (dB), the sound of voices in the classroom, reaches about 50, and the street noise for traffic, is about 90 dB. Noise over 100 dB can become unbearable to the human ear. The noise is about 140 dB (e.g., the sound of a jet airplane taking off) can be painful to the ear and even damage your eardrum.
Most people's hearing acuity is dulled with age. This is due mainly to the fact that the ear bones lose their original mobility, whereby vibrations are not transmitted to the inner ear. In addition, infections of the organs of the ear can damage the eardrum and can have a negative effect on the bones, resulting in deafness.
The reason certain types of deafness is damage to the inner ear or the auditory nerve. The hearing impairment can result in permanent noise impacts (for example, in the factory) or a sudden and loud sound spikes. You should be very careful to use a stereo player because of excessively loud sound can also result in deafness. This is proved by scientists.