NAT L INST. OF STAND & TECH R.I.C. y Ka WMBgiaa i?j vs? : National Bureau of Standard OCT 4 1976 783067“ Quieting: A Practical Guide &£ I . U'T! to Noise Contol t c\ t R# i iq I Raymond D. Berendt and Edith L. R. Corliss Mechanics Division Institute for Basic Standards National Bureau of Standards Washington. I).C. 20234 Morris S. Ojalvo National Science Foundation 1800 G Street, N.W. Washington, D.C. 20006 U.S. DEPARTMENT OF COMMERCE, Elliot L. Richardson, Secretary Dr. Betsy Ancker-Johnson, Assisiani Secretary for Science and Technology 0 ,S , NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director M-i Issued July 1976 Library of Congress Cataloging in Publication Data Berendt, Raymond D. Quieting. (National Bureau of Standards handbook; 119) Includes index. Supt. of Docs, no.: C13.ll: 119 1. Noise control. 2. Soundproofing. I. Corliss, Edith L. R., joint author. II. Ojalvo, Morris S. III. Title. IV. Series; United States National Bureau of Standards. Handbook; 119. QCI00.U565 no. 119 [TD892] 620.2'3 76-5500 National Bureau of Standards Handbook 119 Nat. Bur. Stand. (U.S.), Handb. 119, 163 pages (July 1976) CODEN: NBSHAP U.S. GOVERNMENT PRINTING OFFICE WASHINGTON: 1976 For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 Price $5.10 (Add 25 percent for other than U.S. mailing). Order by SD Catalog No. C 13.11:119/Stock No. 003-003-01646-2 TABLE OF CONTENTS Page CHAPTER 1 INTRODUCTION . 1 WHAT IS NOISE?. 1 HOW DOES NOISE ORIGINATE? . 1 THE CHARACTERISTICS OF SOUND OR NOISE . 2 Decibel, usually written dB . 3 Sound Level Meter . 3 A-weighting . 4 The Notation dB(A) . 6 Frequency and Pitch . 6 Loudness, Sound Pressure and Intensity . 6 Phons. 7 Pure Tone and Broadband Noise. J CHAPTER 2 NOISE AS A HEALTH HAZARD. 8 PRECAUTIONS . 8 WARNING #1 Avoid areas that cause a hearing threshold shift, . 8 WARNING #2 Avoid areas where you must shout to converse . 9 WARNING #3 Avoid areas that cause a tickle sensation in your ears ... 11 HEARING PROTECTION . 12 Situations to Avoid.12 Signs of Hearing Loss.12 Noisy Activities That Should Be Limited.13 HOW TO AVOID RISKING YOUR LIFE AT NOISE LEVELS NOT DAMAGING TO HEARING .... 13 Lesson 1 Provide for sounds of emergency vehicles . l4 Lesson 2 Take frequent rests in quiet areas . 15 Lesson 3 Avoid startle reactions . 15 Lesson 4 Control noise at source.15 CHAPTER 3 BASIC PRINCIPLES OF NOISE REDUCTION . l6 SOURCE-PATH-RECEIVER CONCEPT . l6 NOISE CONTROL AT THE SOURCE.l6 Select Quiet Equipment . l6 REQUIREMENTS FOR QUIET OPERATION . 17 1. Reduce Impact or Impulsive Forces . 17 2. Reduce Speed in Machines, and Flow Velocities and Pressures in Fluid Systems.18 3. Balance Rotating Parts . 20 4. Reduce Frictional Resistance . 20 5. Isolate Vibrating Elements Within the Machine . 23 6. Reduce Radiating Area.26 iii Page 7. Apply Vibration Damping Materials . 26 8. Reduce Noise Leakage From the Interior of the Appliance _ _ 28 9. Choose Quieter Machinery When Replacing Appliances. 29 NOISE CONTROL OF THE TRANSMISSION PATH. 29 FACTORS AFFECTING TRAVEL OF SOUND . 29 1. Absorption: Soaking Up Sound . 29 2. Sound Reflection: Bouncing of Sound. 3P 3. Reverberation: Multiple Reflection of Sound. 32 4. Diffraction: Bending or Squeezing of Sound . 32 "QUIETING" IN THE PATH. 33 1. Separate the Noise Source and Receiver as Much as Possible. .... 33 2. Use Sound Absorbing Materials . 34 3. Use Sound Barriers and Deflectors. 35 4. Use Acoustical Lining. 36 5. Use Mufflers, Silencers or Snubbers . 37 6. Use Vibration Isolators and Flexible Couplers . 3g 7. Use Enclosures... 4q PROTECT THE RECEIVER. 40 USE EAR PROTECTORS. 40 ALTER WORK SCHEDULE. 40 IS THERE AN ACOUSTICAL PERFUME?. 41 CHAPTER 4 NOISE CONTROL AT HOME. 45 TRANSMISSION OF AIRBORNE AND STRUCTUREBORNE NOISE. 45 SOUNDING BOARD EFFECT . 46 FLANKING NOISE TRANSMISSION . 47 GENERAL SOLUTIONS FOR NOISE CONTROL IN THE HOME- . .. 48 SOUND ABSORPTION VS SOUND INSULATION . 50 KITCHEN NOISE . 51 INSTALL DOORS . 52 CONTROL APPLIANCE NOISE . 52 1. Vibration Isolate the Appliance from the Floor . 32 2. Isolate the Appliance from the Wall. 32 3. Isolate the Appliance from the Cabinet Enclosure.. 53 4. Isolate the Cabinet Enclosure from the Wall. 33 5. Isolate Small Appliances .... 33 6. Cushion Impact Noise in the Cabinets . 34 7. Apply Vibration Damping Material . 34 8. Install Acoustical Lining . 34 9. Install Exhaust Fans on Rubber Mounts . 34 10. Install Acoustic Ceiling . 53 11. Install Carpet or Foam-Backed Til&. 33 12. Quieting of Large Appliances. 53 RECREATION OR PLAYROOMS . 57 CORRIDORS, HALLS, STAIRCASES. 58 IMPROVING THE PRIVACY OF YOUR BEDROOM, STUDY OR BATH AREA. 58 IMPROVING THE SOUND INSULATION OF WALLS . 60 IMPROVING THE SOUND INSULATION OF FLOOR-CEILING CONSTRUCTIONS . 65 CONTROL OF FLOOR SQUEAKING. 66 CONTROL OF STAIR SQUEAKING. 69 IV Page CONTROL OF HEATING, VENTILATING AND AIR-CONDITIONING SYSTEM NOISE.70 CONTROL OF DUCT NOISE.74 FURNACE COMBUSTION NOISE . 78 STEAM HEAT NOISE.78 NOISE FROM BASEBOARD HEATING SYSTEMS . 78 CONTROL OF PLUMBING NOISE.79 CONTROL OF NOISE FROM RAIN GUTTERS AND SPOUTS.85 CHAPTER 5 HOW TO INSULATE YOUR HOME AGAINST OUTDOOR NOISE.86 Reducing the Intrusion of Neighborhood Noise . 86 Reducing the Intrusion of Traffic Noise.87 Reducing the Intrusion of Aircraft Noise . 87 CHAPTER 6 SELECTING A QUIET HOME OR APARTMENT (or how to avoid making the same mistake twice) . 97 Selecting a Quiet Residential Area . 97 Selecting a Quiet Location Within a Housing or Apartment Development . 98 Selecting a Quiet Apartment Unit Within the Building.101 CHAPTER 7 A TROUBLE-SHOOTING GUIDE. 102 ANALYZING THE PROBLEM.102 HOW TO LOOK FOR NOISE LEAKS.104 USE YOUR EARS.104 USE HOME APPLIANCES AS DIAGNOSTIC TOOLS.104 COMMON NOISE COMPLAINTS AND LIKELY CAUSES AND SOLUTIONS.107 GENERAL NOISE ABATEMENT TECHNIQUES . 109 INDEXED CATALOG OF SPECIFIC NOISE PROBLEMS AND REMEDIES . 110 CHAPTER 8 NOISE CONTROL AT THE OFFICE AND SCHOOL.127 NOISE SOURCES.127 REDUCING THE NOISE.127 EXTRANEOUS NOISE . 128 PRIVACY BETWEEN OFFICES . 128 PRIVACY IN OPEN-PLAN OFFICES.129 NOISE CONTROL AT SCHOOL.130 CAUSES OF NOISE.131 REDUCING CLASSROOM NOISE . 131 NOISE CONTROL IN MULTIPURPOSE ROOMS . 132 CHAPTER 9 NOISE CONTROL WHILE TRAVELING . 133 AUTOMOBILES.133 1. Select a "Quiet" Automobile . 133 2. Drive at Slower Speeds.133 3. Close Windows for High Speed Driving.133 4. Use Slow Fan Speed.133 5. Turn Off the Radio.133 6. Select Quiet Tires . 134 v Page 7. Balance Car Wheels. 134 8. Reduce Windshield Wiper Noise . 134 BUSES AND TRAINS. 135 AIRPLANES. 135 SELECTING A "QUIET" MOTEL OR HOTEL . 135 SELECTING A "QUIET" ROOM. 137 CHAPTER 10 POLITICAL AND LEGAL ACTION — WHEN ALL ELSE FAILS. 140 INTRODUCTION . 140 FEDERAL NOISE REGULATION . 140 STATE AND LOCAL REGULATION. 141 CORRECTIVE ACTION PROGRAMS . 141 LOCAL NEIGHBORHOOD NOISE PROBLEMS . 142 BIBLIOGRAPHY. 143 INDEX. 145 vi In those days the world teemed; the people multiplied, the world bellowed like a wild bull, and the great god was aroused by the clamour. Enlil heard the clamour and he said to the gods in council, "The uproar of mankind is intolerable and sleep is no longer possible by reason of the babel." So the gods agreed to exterminate mankind. From "The Epic of Gilgamesh" Translated by N. K. Sandars (Penguin Press, 1972) ABSTRACT This guide offers practical solutions for ordinary noise problems that a person is likely to meet. The discussion describes the ways in which sounds are generated, travel to the listener, and affect his hearing and well-being. Recommendations are given for controlling noise at the source and along its path of travel, and for protecting the listener. The guide instructs the reader by way of "Warning Signs" on how to determine whether he is being subjected in his environment to prolonged noise exposures that may prove hazardous to his hearing. Remedies are given for noise problems that a person is likely to find in his home, at work and at school, while traveling , and in the growth and development of his community. The remedies include noise prevention techniques and selection of quiet alternatives to existing noise sources. General principles for selecting quiet appliances are given. Ways of searching for the sources of noise and for determining the paths over which they travel to the listener are described. A detailed index is given for individual noise sources describing specific solutions to the problems they present. General ways of looking for inherently quiet homes and travel accommodations are described. In a final chapter, there are suggestions for enlisting community help where large external sources of noise must be quieted, such as those arising from public utilities and public trans¬ portation. KEY WORDS: Airborne and structure-borne sounds; aircraft noise intrusion; annoyance; appliance noise; health and hearing hazards; household noise; legal and community action; loudness; noise control and abatement; traffic noise. viii QUIETING A PRACTICAL GUIDE TO NOISE CONTROL Raymond D. Berendt, Edith L. R. Corliss and Morris S. Ojalvo Institute for Basic Standards National Bureau of Standards Washington, D. C. 20234 Chapter 1 INTRODUCTION WHAT IS NOISE? molecules, imparting motion to them and then, rebounding back and forth, return to One humorous definition holds that their original positions. The disturbed "Noise is what your neighbor makes." Of molecules collide with others in the same course, we all make noise ourselves, but we manner. The disturbance travels through the especially resent the intrusion of sounds air by successive collisions, much as a that we do not choose to hear. Thus, noise billiard cue ball will impart motion to a may be defined as "unwanted sound." It line of billiard balls.