Our ears are one of the most delicate and extraordinary organs in the body.
To understand the Physiology of the ear we can break the ear anatomy into three regions, Outer Ear, Middle Ear and the Inner Ear.
Outer Ear: The outer part of the ear which is visible to everyone is called Pinna, It consists of the ear lobes, helix, anti-helix, tubercle, the concha (which is nearest to our ear canal), tragus (which projects immediately in front of our ear canal). The hole from where sound travels into our ear canal is called external acoustic meatus and around the ear canal there are a few cartilages to help with support and also the flexibility. At the end of the ear canal is the ear drum which is referred to tympanic membrane, this membrane is about 10 mm wide and has a surface area of 55 square mm. The Tympanic membrane then meets three tiny bones and this is where the middle ear is.
Middle Ear: The middle ear consists of three bones and those bones as a group are called auditory ossicles. The ear drum projects the sound vibrations to these auditory ossicles. The first bone is called the malleus which is connected to incus which is attached to stapes. Stapes the last bone projects vibrations from the ear drum to the oval window which is connected to the labyrinth.
Inner Ear: The auditory ossicles are connected to the inner ear, labyrinth (snail like tube). The labyrinth is made up or vestibule and a semi-circular canal also cochlea. The cochlea is the central part of the inner ear; it is filled with fluid, sensory cells also known as hair cells. Hair cells have varying degrees of sensitivity for detection of different tones and frequencies (which ranges from 20 Hz to 20 kHz). Hair cells in the cochlea are arranged like the keys on the piano. The hair cells at the lower region of cochlea detect the high frequencies and the ones at the apex detect the low frequencies. The cochlea is connected to the auditory nerve which transmits the converted electric signals from sound waves to the brain.
The Process of hearing:
The sound waves enter into our ears starting from the outer ear into the ear canal and they hit the tympanic membrane causing it to vibrate which then causes the movement of the auditory ossicles and stapes passes the vibrations into the cochlea through the oval window. The fluid in the cochlea moves the hair cells in the cochlea which then converts the mechanical energy of sound into the electrical signals which are passed to the brain through the auditory nerve to the temporal lobe in the brain and the brain recognises it as sound.
Types of Hearing Damage:
When you are working in the music industry, your ears are the most important asset you have. It is very important to protect your ears and if you don’t you may end up with hearing problems which may last for ever and destroy your career in the music industry. Listed below are a few types of hearing damage that may occur if your ears are exposed to high levels of sound for a long period of time.
Presbycusis: Presbycusis is age related hearing loss. As you grow older your hearing declines and you have difficulty hearing the higher frequencies. It’s uncertain that what exactly causes Presbycusis but exposure to loud sound for a prolonged period of time may aggravate the condition. This condition can be treated by use of hearing aid or in some severe cases by cochlear implants.
Tinnitus: Tinnitus is the constant ringing noise in the ear someone hears. It is not really a disease but rather a condition in which a person’s brain perceives this sound because of the hearing damage. It is caused due to exposure to loud sound levels for a long period of time, by listening to loud noise for long periods it damages your hearing and you can no longer hear some frequencies and to make up for the loss the brain makes this ringing noise in your ears and it can stay like that temporarily (Temporary threshold shift) which occurs if you have…