Ears. We all have them. Some peoples ears work perfectly, others don’t. Sound is an extraordinary thing.
The Pinna, the part of the ear we can see, collects the sound waves. Sound waves are longitudinal, and have compressions and rarefactions. The compressions and rarefactions travel through the ear canal, sending the sound to the ear drum, causing it to vibrate. The ear drum amplifies sound by the vibrations of tiny bones called ossicles; here sound energy is converted into mechanical energy. The hair cell, nerves, on the cochlea then picks up impulses and sends a signal to the brain. The cochlea is a snail like bony structure in your inner ear that is the main source of your hearing. The impulses are then interpreted as words. If the hair cells are bent, broken, or completely gone, it can result in a degree of hearing loss, or deafness. There are two main types of hearing loss:
Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the ear drum and ossicles. This type of hearing loss can be medically corrected. Some causes are swimmer’s ear, ear infections, and perforated ear drum. Some symptoms may include earaches, pressure in the ear, and muffled sound.
Sensorineural hearing loss occurs when there is damage to the cochlea or to the nerve pathways from the inner ear to the brain. This can’t be medically corrected. This is the most common type of permanent hearing loss. Some causes are exposure to loud noise, illnesses, aging, and it can also be genetic. Some symptoms are dizziness, buzzing in the ear, and speech discrimination.
There are 5 main degrees of hearing loss, and how much you can or can’t hear, the loudness, is measured in decibels. Loudness is also known as amplitude, which is the maximum change a particle experiences from its rest position to a single vibration.
• Mild hearing loss, between 26 and 40 dB is when people have little difficulty hearing speech clearly.
• Moderate hearing loss, between 41-55 dB, is having difficulty haring speech, and following a conversation if people are not loud or close enough.
• Moderate-Severe hearing loss, between 56-70 dB, is when you can typically hear and identify louder environmental sounds such as thunder and possibly sirens.
• Severe hearing loss, between 71-90 dB, is when people usually can’t understand or follow conversation without the help of lip-reading and hearing aids. Also if the speaker isn’t loud or close enough.
• Profound hearing loss, 91 dB and above, is when you generally are not able to hear loud sounds, even with hearing aids, and will use visual language for communication, such as sign language. It is one of the most common ways for deaf and hard of hearing people to communicate.
Depending on how much of a hearing loss you have, you can still hear some noises, though they may be muffled. Hearing aids are often helpful in hearing or making out the sounds better, though they can’t let you hear clearly 100% of the time.