ENVIRONMENTAL NOISE LEVELS
140 dB SPACE ROCKET AT BLASTOFF
JET ENGINE AT TAKEOFF
120 AMBULANCE SIREN
AMPLIFIED ROCK BAND
117 THE SHUTTLE TAKE-OFF IN “ARMAGEDDON”
CHILDREN’S TOYS AT EAR (BIKE HORNS, MUSICAL INSTRUMENTS,CAP GUNS,BEEPERS)
114 GODZILLA SHREIKING IN “GODZILLA”
110 WOODWORKING SHOP
100 PNEUMATIC DRILL
90 AVERAGE DENTAL DRILLS (77-96)
PRINTING PRESS PLANT
TV COMMERCIAL (87)
80 CITY TRAFFIC
INSIDE SPORTS CAR (50 MPH)
LOUD MUSIC FROM RADIO
75 KITCHEN APPLIANCES
70 CROWDED FAMILY RESTAURANT
65 CONVERSATIONAL SPEECH
60 SEWING MACHINE
50 AVERAGE HOME INTERIOR
INSIDE CAR AT 50 MPH
LARGE STORE (50-60)
40 QUIET RESIDENTIAL COMMUNITY
30 WHISPER AT 5 FT
20 LEAVES RUSTLING IN A BREEZE
10 NORMAL HEARING
110 dB Regular exposure of more than 1 minute risks permanent hearing loss.
100 dB No more than 15 minutes unprotected exposure is recommended.
90 dB Any prolonged exposure above 90 dB may cause gradual hearing loss.
When people have their hearing examined by an audiologist, pitch sounds between 250-8,000 Hz are routinely measured. These are tested because they are the most important for understanding speech.
More recently, some researchers have begun to look at how noise may affect hearing for the very high pitch sounds- those between 9,000 & 18,000 Hz, known as the extended high frequencies.
Research has found that some people who are exposed to loud noise have reduced hearing in the extended high frequencies, but not in the more conventional (250-8,000 Hz) frequency range. Based on these findings, it has been suggested that a noise induced hearing loss may be detectable at an earlier stage by testing hearing in the extended high frequencies.