Hearing and the Ear

Ear drum

Semicircular canal

Hammer, Anvil Stirrup

Cochlea

Nerve to brain

Eustachian tube

Loud Sounds & Loss of Hearing• The louder and longer you are exposed to a loud

sound, the more damage will be done to your hearing. This is known as Noise Induced Loss of Hearing.

• Damage happens to the microscopic hair cells found inside the cochlea. These cells respond to mechanical sound vibrations by sending an electrical signal to the auditory nerve.

• Over time, the hairs may get damaged or broken. If enough of them are damaged, hearing loss results.

Approx. DecibelLevel Example Max Exposure

0 Faintest sound heard by human ear.

30 Whisper, quiet library.

60 Normal conversation, sewing machine, typewriter.

90 Lawnmower, shop tools, truck traffic;

8 hours per day

100 Chainsaw, pneumatic drill; 2 hours per day

115 Loud rock concert, car horn; 15 minutes per day

140 Gun, jet engine; Brief exposure may cause damage.

Maximum allowed noise with hearing protectors.

60-70 dB Normal piano practice

70 dB Fortissimo singer 3 ft. away

75-85 dB Chamber music in small auditorium

84-103 dB Violin

85-111 dB Flute

85-114 dB Trombone

106 dB Timpani & bass drum rolls

120 - 137 dB Symphonic music peak

150 dB Rock music peak

Other types of damage• Loud sounds can also:

– burst the ear drum

– Damage the nerve endings

– Damage the bones of the middle ear

– Result in ‘tinnitus’ or ‘ringing in the ear’

Sound and Hearing Notes