Why do people hear pitches differently

Human hearing range and hearing ability

Hearing begins with a sound source, e.g. B. a voice, a bell, the engine of a car, a loudspeaker. From the sound source, the sound spreads in waves, the air serves as a means of transport. Without such a transmitting medium, we would not hear anything: sound cannot be passed on in a vacuum. The sound thus reaches the human ear via the air, more precisely to the auricle first. From here it makes its way through the middle ear to the inner ear and is ultimately interpreted by the brain in order to be able to react appropriately. Our blog article "The ear - a small miracle" provides information about the structure of the ear.

Sound is measured in two different units of measurement: in decibels, which indicate the volume, and in Hertz, which indicate the frequency (i.e. the number of double vibrations per minute) and determine the pitch. The listening field, d. H. the range of perception of a healthy young adult is between 0 and 10 decibels. The “pain threshold” is usually around 120 decibels and is not called that for nothing: At this volume we don't hear anything, we just feel pain. However, even with values ​​below this, a certain degree of caution is an advantage. Hearing can be permanently damaged from around 85 decibels. This is why hearing protection is so important.

The language banana: what is it?

This term needs some explanation: The language banana describes in an audiogram the area that we perceive with the spoken language. It results from the vertical axis, on which the volume is specified in decibels, and the horizontal axis, which describes the pitch in hertz. The range between 125 Hertz (low) and 8000 Hertz (high) is primarily important for understanding speech. The sounds m, n, d, b, e, l and u are in the left part of the auditory banana. In the middle area there are vowels and the sounds p, h, g, ch, and sh. On the far right are the sibilants z, sch, s and f.

With the help of speech audiometry or a speech audiogram, it is possible to examine a person's hearing ability. This examination is usually carried out by an ENT doctor or an acoustician. The person to be examined hears words and numbers, whole sentences or single syllables through headphones. Then she states what she heard. In order to adjust a hearing aid reliably, this examination is absolutely necessary. This is followed by the evaluation of the speech audiometry by the acoustician or ENT doctor. The results show whether and which impairments of hearing are present.

Frequency and decibels when listening

The sound frequency describes the vibrations that a sound wave has per second. Young and healthy human ears perceive a frequency range of 20 to 20,000 Hertz. That is quite a lot, and you can well imagine the flood of sound pouring down on us. But the human hearing is clever and sorted: It is particularly sensitive to a frequency range between 500 and 5,000 Hertz, the range in which human speech also moves. This saves us a lot of unnecessary "background noise". However, if the decibels and volume rise too much, this poses a risk to hearing. People who work in noisy environments should therefore consider hearing protection to protect their hearing from noise in the high decibel range.

What do we hear

Most living things have two ears on their heads with which they perceive their environment. Nevertheless, a person's hearing differs significantly from that of an owl or a mole. Every animal species and also humans perceive a very specific range of frequencies and pitches. A human ear perceives the range between 500 and 4,000 Hertz as pleasant. The volume of a sound is measured in decibels. The hearing threshold is given as zero decibels. From this volume onwards, the human ear is able to perceive a sound. As soon as the noises get too loud, they reach the pain threshold, which can cause significant damage to the ear. This is 120 decibels. The hearing threshold changes with age: sounds that were previously perceived without any problems now elude the hearing of the person affected.

What can we not hear?

With our ears we can perceive many thousands of tones in everyday life, be it music, language or nature noises. Nevertheless, the area that is below the hearing threshold remains hidden from us. These include, for example, ultrasonic waves. Some animals have a listening area that covers these tones as well. They include dolphins, among others. But not all people can call their own good hearing. With increasing age, many people develop age-related hearing loss, which primarily means that high frequencies are no longer perceived. Without providing the hearing loss with a hearing aid, the brain forgets in the long run how to correctly assign and interpret these tones.

Hearing impairments

There are different types of hearing loss, but not all of them are permanent. Some hearing loss is temporary. Causes for this are, for example, a sudden hearing loss or an earwax plug. Tinnitus can also cause temporary hearing loss. If there are additional complaints, such as dizziness, nausea or tremors, the cause may be Menière's disease, which requires medical clarification.

Conductive hearing loss

The term conductive hearing loss refers to hearing damage that affects the outer and middle ear. The cause of around 20% of all hearing impairments is sound conduction. A blockage of the ear canal, for example by a foreign body or an inflammation of the ear canal, prevents the transmission of the sound. It is also possible that the middle ear was damaged as a result of otosclerosis or otitis media.

Sensorineural hearing loss

Sensorineural hearing loss describes hearing impairments, the cause of which can be found in the inner ear or the auditory nerve. Often there is permanent damage to the hair cells, which reduces the hearing area. The disturbed processing of the acoustic stimuli leads to the sound and volume being felt more strongly.

Stages of hearing loss

Hearing impairment does not arise overnight, but is a gradual process that can drag on for several years and increasingly occurs as age-related hearing loss with increasing age. This process goes through different stages.