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

More documents

Recommendations

Info

28 CHAPTER 2. THE HUMAN HEARING SYSTEMFigure 2.4: The zone of speech. Source : Bruël&Kjær.tones in the speech intelligibility area. Due to a leverage effect, the forcesexerted on the middle ear are amplified with approximately factor three (seeFigure 2.5). Note that although the forces are amplified, the displacementsare attenuated (due to the conservation of energy of the sound wave). Secondly,an amplification of the forces is realised due to the ratio between thesection of the eardrum (where the sound wave strikes) and the oval window(where the sound wave is transmitted to the cochlea).The amplification in the inner ear depends on the frequency of the stimulants,acting on different locations in the cochlea (Figure 2.6). The functioningof the inner ear relies on the propagation of waves on the basilarmembrane. At low frequencies the maximum of the displacement is situatedfurther away in the cochlea (since at any wave length energy is lost,the low frequencies propagate further in comparison with higher tones). Athigh frequencies, the maximum is situated near the oval window. moreover,the stiffness of the membranes in the organ of Corti tuned on the differentfrequency bands that need to be perceived in the different places along thecochlear duct.
2.2. PHYSIOLOGY OF THE EAR 29Figure 2.5: Amplification of the sound by the ossicles.Figure 2.6: Changing cross section of the cochlea to realize a frequency dependenthearing mechanism.
Page 1: VRIJE UNIVERSITEITBRUSSELAcousticsB
Page 4 and 5: iiWhen sound becomes noise, it will
Page 7 and 8: ContentsI Introduction to acoustics
Page 9 and 10: CONTENTSvii4.3 Measuring the acoust
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 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 81 and 82: 4.3. MEASURING THE ACOUSTIC ABSORPT
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 ...

Create successful ePaper yourself

Delete template?

Save as template?