Tag Archives: noise protection

Noise Induced Hearing Loss

A teenage girl visited ENT clinic with her mother with ringing in the ear and felt like cotton in the ear. Previous night,  Diwali Night she had spent several hours setting off the fire crackers.

Her ear were normal on video otoscopy and Audiogram showed  35 db at 4000 and 8000 hertz, Several days later, her hearing had returned to normal.

This patient is an example of a “temporary threshold shift.” Or Reversible Hearing Loss by exposure to an intense “impulse” sound such as fireworks or loud rock concert.

If sound is too loud or duration of exposure is long enough, such as noise generated in a woodworking shop it may lead to permanent threshold shift.  This condition is called Noise Induced Hearing Loss which has no cure.

Acoustic trauma occurs when excessive sound energy strikes inner ear. When we are exposed sounds that are too loud or loud sounds that last a long time—small sensitive structures in our inner ear, called hair cells, can be damaged, Hair cells convert sound energy into electrical signals that travel to the brain. The louder the sound, the shorter the time period before NIHL can occur.

Sound is measured in units called decibels. Continual exposure to more than 85 decibels (dB) is dangerous to the ears. Firecrackers emit sounds from 120 to 160 decibels. Sound with 140dB can cause ear ache. A very high intensity sound (above 160 dB) may also damage the ear drum and can cause dislocation of middle ear ossicles.

An even higher intensity may cause leakage of inner ear fluid leading to permanent hearing loss associated with dizziness.

Symptoms

  • Hearing loss
  • Sense of fullness  the ear
  • Noises, ringing in the ear
  • Earache
  • Bleeding from the are
  • Dizziness,

Signs and tests

Acoustic trauma is suspected if hearing loss occurs after noise exposure. Audiometry may determine how much hearing has been lost. Audiogram has typical “notch” at 4000 hz, with better hearing at both lower and higher frequencies. Otoacoustic Emisson (OAE) testing is very sensitive to noise induced hearing loss.

Treatment

The hearing loss may not be treatable. The goal of treatment is to protect the ear from further damage. Hearing aid is prescribed for communication needs. If ear Drum is ruptured, surgery to repair ear drum may be needed.

Ear protection using noise protector ear plugs or ear muffs may prevent the hearing loss from getting worse.

Noise exposure, whether occupational or recreational, is the leading preventable cause of hearing loss. It can be prevented by avoiding “too loud” or “too long” Noise exposure and use of hearing protection when necessary.

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It’s a Noisy Planet. Protect Their Hearing campaign, a program of the National Institute on Deafness and Other Communication Disorders (NIDCD).
NIDCD

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Happy new year and “safe ear”- protect ear from noise

Noise-induced Hearing loss

  • Noise level goes up with new year celebrations, social gatherings, party, music, rock-concert and fire works, and so does people visiting E.N.T. and audiology clinics with hearing problems or ringing in the ear(tinnitus).

· Children and teens listening to loud music are also more prone to develop hearing loss later in life.

· People with occupations involving exposure to noise above 85 decibel over an 8 hour period daily are also at risk. These includes indusries like mining, construction, drilling and agriculture.

  • And now people who love to play golf using latest titanium drivers are at risk of reduced hearing because of noice generated when it strikes the ball. (ref-British medical journal)

How noise causes hearing loss?

Too loud noise damages sensitive nerve endings in inner ear (delicate cells called cillia) and cause sensorineural loss. Sensitivity to sound is different for each person.

Sudden exposure to loud noise may cause temporary sensorineural hearing loss which usually recovers over 24 to 48 hours.

But if sound is too loud, or loud sound is too close or loud sound is exposed over a long period of time(more than 85 db), permanent sensorineural hearing loss can occur.

And 85 decibels is not as loud as you will think. Sound from an ipod shuffle is usually 115 db, and with fireworks it goes at 150 db.

Tinnitus may be presenting complaint for some person.

Protection from noise

Photograph taken from www.visualdictionaryonline.com
Photograph taken from http://www.visualdictionaryonline.com
  • Person working in noise above 85 db should use noise protection devices-ear plugs and ear muffs. It is as simple a concept as using goggles to protect your eyes from UV rays of sun. It is for Musicians also.
  • · People with occupations involving noise exposure should undergo periodic hearing screening(audiometry test).

    · On earliest sign of noise trauma like irritability, buzzing sound in ear or difficulty in hearing visit your physician.

· Turn down the volume of television and MP3 players.

  • Do not stand directly near to the source of noise.

Unfortunately physician can not do much in sensorineural hearing loss except prescribing a hearing aid. So primary aim is prevention and early detection.