Buying headphones for an iPod or MP3 player is a big challenge. It’s not just that they should look good and provide excellent sound quality. The main point is not to make them deaf.
Users of iPods or MP3 players most often use in-ear headphones, i.e. headphones that are inserted inside the ear. Unfortunately, these are the causes of hearing loss. The best are over-the-ear, semi-open headphones, i.e. those that are not put into the ear canal. Their sealing earpieces do not cover the entire pinna, which allows for ear ventilation. Before the acoustic wave hits the eardrum, it is “absorbed” by the air cushion that forms between the loudspeaker and the membrane and by the ear cushions.
Safe sound level
Good headphones are not everything. The intensity of the sounds heard is also a problem. Until fifteen years ago, senile hearing loss occurred almost exclusively in people over 70 years of age. Today, almost half of people with hearing loss are under 55 years of age. Most of them are users of portable music playback devices who do not listen to it adequately.
The intensity of the sound generated by the player at the maximum setting of the volume potentiometer in the in-ear headphones can reach up to 100 decibels. It is almost the sound of a jackhammer or a plane taking off. For comparison – a whisper is only 30 decibels, speech is 60-65 dB, and a shout is 85 dB. Dr. Michał Wątróbski, a specialist in otorhinolaryngology, emphasizes that the limit of safety is the intensity of sounds with a value of 80 decibels. Listening to louder sounds for more than half a minute a day can permanently damage your hearing.
The operation of the human ear
The hearing cells, thanks to which we hear the sounds around us, are located deep in the inner ear. Sound waves traveling through the air are picked up by the auricle and cause the eardrum to vibrate. These vibrations are transferred to the cochlea – a bone canal filled with fluid. There, they find cells which, due to the pressure of the fluid, bend in response to the sound they hear. This process triggers a biochemical reaction that sends a signal to the brain. Then we hear. Man is born from around 50. such cells. Their number decreases with age. They are also damaged by diseases and injuries caused by noise. The problem is that these cells do not regenerate and the hearing loss is irreversible.
Effects of excessive noise
The dying of our hair cells manifests itself in the inability to hear higher frequencies (high tones), difficulty understanding speech in noisy environments, and ringing and tinnitus. In addition to hearing loss, noise can cause fatigue, inability to concentrate, confusion, irritability, increase in blood pressure, pain and dizziness.
To avoid damaging our hearing cells, we should never listen to music using headphones at maximum volume. Half the volume scale is safe. It is also important not to use channel headphones. Apart from the fact that they damage hearing – their mere presence in the ear canal irritates the ears and forces them to produce an excessive amount of earwax. In addition, if we do not store them in a special container and do not care about their cleanliness, we can get otitis.
Text: Halina Pilonis