Introduction

While society has made great advances in technology and industry in order to help humans thrive, this progress has also made the world a noisier place in which to live. Every day, humans are exposed to a variety of sounds in the environment, including recreational and occupational noise such as, ipods, televisions, car alarms, lawn mowers, traffic, and household appliances. When exposed to these potentially harmful sounds that last a long time or are too loud the ear can be damaged, causing noise-induced hearing loss (NIHL). I choose to do this project because I am a communication disorders major with an interest in audiology and because my father as well as one-third of Americans suffer from NIHL.

Background Information

Noise-induced hearing loss is a type of sensorineural hearing loss because sensitive structures in the inner ear called hair cells become damaged. Hair cells are small sensory cells that convert sound energy into electrical signals that travel to the brain allowing one to hear at different frequencies. Exposure to loud noise caused by a one-time exposure to an intense sound, such as an explosion, or continuous exposure to loud sounds over a period of time can cause hair cells to die. Once damaged the hair cells are unable to grow back causing mild, moderate, severe, or profound hearing loss. NIHL may be accompanied by tinnitus, which is a ringing or buzzing sound in the ears or head.

Sounds louder than 80dB are considered potentially hazardous.

Noise	Decibel Level
Fire Arms or Jet Engine	140 dB
Car Stereo, Band Practice	120 dB
Lawnmower, Truck Traffic, Subway	90 dB
Alarm Clock, Busy Street	80 dB
Conversation	60 dB
Whisper	30 dB

"Noise and Hearing Loss". American Speech-Language-Hearing Association. Retrieved April 5, 2010 .