VRIJE UNIVERSITEIT BRUSSEL Acoustics - the Dept. of ...

More documents

Recommendations

Info

viCONTENTS2.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . 302.3.2 Development of the ear with age . . . . . . . . . . . . . 302.4 The human perception of sound . . . . . . . . . . . . . . . . . 312.4.1 The phon . . . . . . . . . . . . . . . . . . . . . . . . . 312.4.2 The sone as measure of loudness . . . . . . . . . . . . . 313 Measuring sound 333.1 Introduction: why measure sound . . . . . . . . . . . . . . . . 333.2 The measurement microphone . . . . . . . . . . . . . . . . . . 333.2.1 Size of the microphone . . . . . . . . . . . . . . . . . . 353.2.2 The sound field where measurements take place . . . . 363.2.3 Influence of the wind speed . . . . . . . . . . . . . . . 373.2.4 Division of sound in frequency bands . . . . . . . . . . 393.3 Frequency weighting of microphone signals . . . . . . . . . . . 413.4 The sonometer . . . . . . . . . . . . . . . . . . . . . . . . . . 423.5 Calibration of measurement systems . . . . . . . . . . . . . . . 443.6 Presence of the observer . . . . . . . . . . . . . . . . . . . . . 443.7 Background noise . . . . . . . . . . . . . . . . . . . . . . . . . 453.8 Quantitative parameters . . . . . . . . . . . . . . . . . . . . . 463.8.1 The equivalent sound pressure level . . . . . . . . . . . 463.8.2 Sound Exposure Level . . . . . . . . . . . . . . . . . . 473.8.3 Statistic sound levels . . . . . . . . . . . . . . . . . . . 473.8.4 The Noise Rating value . . . . . . . . . . . . . . . . . . 483.8.5 The nuisance of fluctuating sound . . . . . . . . . . . . 493.9 The intensity meter . . . . . . . . . . . . . . . . . . . . . . . . 503.10 Measuring sound sources . . . . . . . . . . . . . . . . . . . . . 523.10.1 Measurements in an anechoic half-space . . . . . . . . 523.10.2 Measurements in a full anechoic room . . . . . . . . . . 543.10.3 The comparison method . . . . . . . . . . . . . . . . . 553.10.4 Power measurement with an intensity meter . . . . . . 55II Noise control 574 Sound Absorption 594.1 Acoustic transmission between two media . . . . . . . . . . . . 594.1.1 Normal incidence . . . . . . . . . . . . . . . . . . . . . 604.2 Realization of acoustic absorption . . . . . . . . . . . . . . . . 644.2.1 Plate on an air layer . . . . . . . . . . . . . . . . . . . 644.2.2 Helmholtz resonator . . . . . . . . . . . . . . . . . . . 654.2.3 Porous acoustic absorbing materials . . . . . . . . . . . 67
CONTENTSvii4.3 Measuring the acoustic absorption . . . . . . . . . . . . . . . . 704.3.1 Reverberation time . . . . . . . . . . . . . . . . . . . . 704.3.2 Measuring the absorption in a reverberation room . . . 754.3.3 Measuring the absorption in the Kundt tube . . . . . . 754.4 The direct and diffuse sound field . . . . . . . . . . . . . . . . 775 Sound Insulation 815.1 Measuring sound insulation . . . . . . . . . . . . . . . . . . . 815.1.1 Measuring airborne sound insulation . . . . . . . . . . 815.1.2 Measurement of impact sound . . . . . . . . . . . . . . 845.1.3 Single number rating . . . . . . . . . . . . . . . . . . . 855.2 Airborne sound insulation of a wall . . . . . . . . . . . . . . . 865.2.1 Simple law . . . . . . . . . . . . . . . . . . . . . . . . . 865.2.2 Effect of the wall stiffness . . . . . . . . . . . . . . . . 885.2.3 The coincidence effect . . . . . . . . . . . . . . . . . . 905.2.4 Insulation of double wall constructions . . . . . . . . . 925.2.5 Insulation of a composite wall . . . . . . . . . . . . . . 945.3 The acoustical barrier . . . . . . . . . . . . . . . . . . . . . . 956 Noise control 996.1 Origin of noise . . . . . . . . . . . . . . . . . . . . . . . . . . . 996.2 Reducing noise at the level of the sound source . . . . . . . . . 1026.2.1 Aerodynamic noise sources . . . . . . . . . . . . . . . . 1026.2.2 Sources of hydrodynamic noise . . . . . . . . . . . . . . 1056.2.3 Sources of structure-borne noise . . . . . . . . . . . . . 1086.3 Tackling noise transmission . . . . . . . . . . . . . . . . . . . 1106.3.1 Transmission of aerodynamic noise . . . . . . . . . . . 1106.3.2 Hydrodynamic noise transmission . . . . . . . . . . . . 1126.3.3 Structure-borne noise transmission . . . . . . . . . . . 1136.4 Radiation noise . . . . . . . . . . . . . . . . . . . . . . . . . . 115III Noise directives 1197 Directive 2000/14/EG : ’Machines in open air’ 1238 Noise on the work floor 1278.1 Previous guideline . . . . . . . . . . . . . . . . . . . . . . . . . 1278.2 Present guideline: directive 2003/10/EG . . . . . . . . . . . . 1298.3 Risk of hearing damage . . . . . . . . . . . . . . . . . . . . . . 1328.4 The audiometric examination . . . . . . . . . . . . . . . . . . 135
Page 1: VRIJE UNIVERSITEITBRUSSELAcousticsB
Page 4 and 5: iiWhen sound becomes noise, it will
Page 7: ContentsI Introduction to acoustics
Page 11: Part IIntroduction to acoustics1
Page 14 and 15: 4 CHAPTER 1. FUNDAMENTAL CONCEPTS O
Page 20 and 21: 10 CHAPTER 1. FUNDAMENTAL CONCEPTS
Page 34 and 35: 24 CHAPTER 2. THE HUMAN HEARING SYS
Page 44 and 45: 34 CHAPTER 3. MEASURING SOUNDconver
Page 46 and 47: 36 CHAPTER 3. MEASURING SOUNDFigure
Page 54 and 55: 44 CHAPTER 3. MEASURING SOUNDfactor
Page 58 and 59:
48 CHAPTER 3. MEASURING SOUNDFigure
Page 60 and 61:
50 CHAPTER 3. MEASURING SOUNDFor ex
Page 62 and 63:
52 CHAPTER 3. MEASURING SOUNDderiva
Page 64 and 65:
54 CHAPTER 3. MEASURING SOUNDThe so
Page 66 and 67:
56 CHAPTER 3. MEASURING SOUND
Page 69 and 70:
Chapter 4Sound AbsorptionAll(constr
Page 71 and 72:
4.1. ACOUSTIC TRANSMISSION BETWEEN
Page 73 and 74:
4.1. ACOUSTIC TRANSMISSION BETWEEN
Page 75 and 76:
4.2. REALIZATION OF ACOUSTIC ABSORP
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
4.3. MEASURING THE ACOUSTIC ABSORPT
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
4.4. THE DIRECT AND DIFFUSE SOUND F
Page 89 and 90:
4.4. THE DIRECT AND DIFFUSE SOUND F
Page 91 and 92:
Chapter 5Sound InsulationWhen consi
Page 93 and 94:
5.1. MEASURING SOUND INSULATION 83F
Page 95 and 96:
5.1. MEASURING SOUND INSULATION 85F
Page 97 and 98:
5.2. AIRBORNE SOUND INSULATION OF A
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
5.3. THE ACOUSTICAL BARRIER 95For t
Page 107 and 108:
5.3. THE ACOUSTICAL BARRIER 97Figur
Page 109 and 110:
Chapter 6Noise control6.1 Origin of
Page 111 and 112:
6.1. ORIGIN OF NOISE 101Figure 6.2:
Page 113 and 114:
6.2. REDUCING NOISE AT THE LEVEL OF
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
6.3. TACKLING NOISE TRANSMISSION 11
Page 123 and 124:
6.3. TACKLING NOISE TRANSMISSION 11
Page 125 and 126:
6.4. RADIATION NOISE 115Figure 6.17
Page 127 and 128:
6.4. RADIATION NOISE 117Figure 6.20
Page 129:
Part IIINoise directives119
Page 132 and 133:
122
Page 134 and 135:
124CHAPTER 7. DIRECTIVE 2000/14/EG:
Page 136 and 137:
126CHAPTER 7. DIRECTIVE 2000/14/EG:
Page 138 and 139:
128 CHAPTER 8. NOISE ON THE WORK FL
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
140 CHAPTER 9. COMMUNITY NOISE2. No
Page 152 and 153:
142 CHAPTER 9. COMMUNITY NOISE
Page 154 and 155:
144 APPENDIX A. MATERIAL PROPERTIES
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162:
152 BIBLIOGRAPHY[12] Bruel and Kjae
show all

VRIJE UNIVERSITEIT BRUSSEL Acoustics - the Dept. of ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?