Acceptable Noise

In common use, the word noise means any unwanted sound. The amplitude level of the undesired background noise is measured in terms of decibel.

Noise is sound that people do not like. Noise can be annoying and it can interfere with your ability to work by causing stress and disturbing your concentration. Noise can cause accidents by interfering with communication and warning signals. Noise can cause chronic health problems. Noise can also cause you to lose your hearing.

Here are some interesting numbers, collected from a variety of sources that help one to understand the volume levels of various sources and how they can affect our hearing.

Environmental Noise
Weakest sound heard	0dB
Whisper Quiet Library	30dB
Normal conversation (3-5')	60-70dB
Telephone dial tone	80dB
City Traffic (inside car)	85dB
Train whistle at 500', Truck Traffic	90dB
Subway train at 200'	95dB
Level at which sustained exposure may result in hearing loss	90 - 95dB
Pain begins	125dB
Even short term exposure can cause permanent damage - Loudest recommended exposure with hearing protection	140dB
Jet engine, Gun Blast	140dB
Death of hearing tissue	180dB
Loudest sound possible	194dB

OSHA Daily Permissible Noise Level Exposure
Hours per day	Sound level
8	90dB
6	92dB
4	95dB
3	97dB
2	100dB
1.5	102dB
1	105dB
.5	110dB
.25 or less	115dB

Perceptions of Increases in Decibel Level
Imperceptible Change	1dB
Barely Perceptible Change	3dB
Clearly Noticeable Change	5dB
About Twice as Loud	10dB
About Four Times as Loud	20dB

Sound Levels of Music
Normal piano practice	60 -70dB
Fortissimo Singer, 3'	70dB
Chamber music, small auditorium	75 - 85dB
Piano Fortissimo	84 - 103dB
Violin	82 - 92dB
Cello	85 -111dB
Oboe	95-112dB
Flute	92 -103dB
Piccolo	90 -106dB
Clarinet	85 - 114dB
French horn	90 - 106dB
Trombone	85 - 114dB
Tympani & bass drum	106dB
Walkman on 5/10	94dB
Symphonic music peak	120 - 137dB
Amplifier rock, 4-6'	120dB
Rock music peak	150dB

Location	Effects	Leq (dBA)	Time (hours)	Time of day
Bedroom	sleep disturbance, annoyance	> 30	8	night
Living area	annoyance, speech interference	> 50	16	day
Outdoor living area	moderate annoyance	> 50	16	day
Outdoor living area	serious annoyance	> 55	16	day
Outdoor living area	sleep disturbance, with open windows	> 45	8	night
School classroom	speech interference, communication disturbance	> 35	8	day
Hospitals patient rooms	sleep disturbance, communication interference	> 30-35	8	day and night