6th Grade Objective 1.6

Objective 1.6 Summarize protective measures for ears and hearing.

The Ear

How do You Hear? How does sound get into your brain? http://www.youtube.com/watch?v=ahCbGjasm_E&feature=player_detailpage OR http://www.interactive-biology.com/1919/how-sound-is-transferred-to-the-inner-ear-episode-37/

Noise Levels by Daily Activity Source of Noise Sound level (dB) Firearms 140 to 170 Jet engines 140 Rock concerts 90 to 130 Amplified car sound systems 140 (at full volume) Portable stereos (e.g., MP3 players) 115 (at full volume) Power mowers 105 Subway trains 100 Video arcades Electric razors 85 Crowded school buses School recesses or assemblies

Noise Pollution What Is Noise Pollution? sounds that cause harm/loss to one’s hearing How Can You Reduce Noise Pollution?

Hearing Loss Hearing loss can result from damage to structures or nerve in the inner ear that respond to sound. This type of hearing loss, termed “noise-induced hearing loss,” is usually caused by exposure to very loud sounds and cannot be medically or surgically corrected.

Hearing Loss Sound intensity is measured in decibels with a sound level meter. Noise-induced hearing loss can result from a one-time exposure to a very loud sound, blast, impulse, or by listening to loud sounds over an extended period. The louder the sound, the shorter the time period before hearing damage occurs.

Hearing Loss Because the damage from noise exposure is usually slow, a person might not notice or might ignore signs of hearing loss until more symptoms of permanent hearing loss become evident.

Signs of Hearing Loss Noticeable signs of hearing loss can include the following: Muffled or distorted hearing Difficulty hearing sounds such alarm clocks, watch alarms, telephones, or doorbells Difficulty understanding speech during telephone conversations or while participating in group conversations Pain or ringing in the ears after exposure to very loud sounds

Book Work Page 145 #’s 1-4 Page 147 #’s 1-5 Page 151 #’s 1-7