Malcolm J. Crocker - Engineering Acoustics

4 Chapter 4 Figure 4.1 Simplified cross‐section through the human ear. Figure 4.2 Tympanic membrane (eardrum) and three auditory ossicles. Figure 4.3 Section through the cochlea and details of the organ of Corti. Figure 4.4 Cochlea “unwrapped” to show working of the ear schematically. Figure 4.5 Human auditory field envelope. Figure 4.6 Equal loudness contours. The contours join the sound pressure lev... Figure 4.7 Relationship between the loudness (in sones) and the loudness lev... Figure 4.8 Contours of equal loudness index. Figure 4.9 Contours joining sound pressure levels of pure tones at different... Figure 4.10 Masking of tones by noise at different frequencies and sound pre... Figure 4.11 Masking effect of a narrow‐band noise of bandwidth 160 Hz center... Figure 4.12 Postmasking at different masker sound pressure levels [17]. Figure 4.13 Postmasking of 5‐ms, 2‐kHz tones preceded by bursts of uniform m... Figure 4.14 A‐, B‐, and C‐weighting filter characteristics used with sound l... Figure 4.15 Relation between subjective response and A‐weighted sound pressu... Figure 4.16 Loudness level in phons of a band of filtered white noise center... Figure 4.17 Dependence of loudness level L N(left ordinate) on duration T io... Figure 4.18 Critical bandwidth, critical ratio, and equivalent rectangular b... Figure 4.19 Relations between bark scale and frequency scale [17, 18]. Figure 4.20 Masking patterns [17, 18] of narrow‐band noises centered at diff... Figure 4.21 Schematic illustration of Zwicker's loudness model [17, 18]. Figure 4.22 Illustration of temporal effects in loudness processing [17, 18]... Figure 4.23 Block diagram of a dynamic loudness meter (DLM) [46]. Figure 4.24 Shift in hearing threshold at different frequencies against age ... Figure 4.25 Sectional view of the head showing the important elements of the... Figure 4.26 Directivity patterns for the human voice in a horizontal plane.... Figure 4.27 Directivity patterns for the human voice in a vertical plane....

5 Chapter 5 Figure 5.1 Differences in percentages of occurrence of various physiological... Figure 5.2 Incidence of hypertensive men and women workers (above and below ... Figure 5.3 Relative risks (odds ratio) for myocardial infarction due to road... Figure 5.4 Electron microscope image of the hair cells in the cochlea (a) ha... Figure 5.5 Schematic representation of the two basic impulse noise pressure–... Figure 5.6 Comparison of duration per day for allowable A‐weighted noise exp... Figure 5.7 Four basic types of hearing protector devices (HPDs). Figure 5.8 Mechanical model of the human body showing resonance frequency ra...Figure 5.9 Reiher‐Meister chart of human response to vertical vibrations [45...Figure 5.10 Acceleration frequency weightings for whole‐body vibration and m...Figure 5.11 Acceleration frequency weighting W hfor the evaluation of hand‐t...

6 Chapter 6Figure 6.1 The bottom curves (marked Hearing Threshold) show the absolute th...Figure 6.2 Contours of perceived noisiness.Figure 6.3 Typical noise history of a fanjet aircraft flyover [13].Figure 6.4 How tone‐corrected perceived noise level may vary in an aircraft ...Figure 6.5 Talker‐to‐listener distances (m) for male speech communication to...Figure 6.6 Comprehensive diagram summarizing speech levels for communication...Figure 6.7 Noise criterion (NC) curves.Figure 6.8 Noise rating (NR) curves.Figure 6.9 Room criterion (RC) curves.Figure 6.10 Balanced noise criterion (NCB) curves.Figure 6.11 Equivalent sound pressure level.Figure 6.12 (a) Percentile levels and (b) cumulative probability distributio...Figure 6.13 A‐weighted sound pressure levels measured in 1971 at 18 location...Figure 6.14 Annoyance as a function of noise level.Figure 6.15 Variation of percentile levels throughout 24 hours periods recor...Figure 6.16 Proposed sleep disturbance curve based on data of Pearsons et al...Figure 6.17 Curves representing the percentage of subjects that are highly a...Figure 6.18 Curves representing the percentage of subjects that are highly a...Figure 6.19 Curves representing the percentage of subjects that are highly a...Figure 6.20 Scale of vibration discomfort from British Standard 6841 and Int...Figure 6.21 Response of building in good condition to vibration (*Rendering ...

7 Chapter 7Figure 7.1 Idealized noise or vibration‐measuring system.Figure 7.2 Sensitivity of (i) an ideal microphone or accelerometer ______ an...Figure 7.3 Sensitivity of an ideal microphone or accelerometer showing upper...Figure 7.4 Inherent noise floor against upper limiting sound pressure level ...Figure 7.5 Comparison of the dynamic ranges of the same four condenser micro...Figure 7.6 Frequency response of an ideal microphone or accelerometer.Figure 7.7 Comparison of the frequency response ranges of four different dia...Figure 7.8 Cross‐section through a 1‐in. condenser microphone.Figure 7.9 Electret microphone using a thin electret polymer layer deposited...Figure 7.10 Cross‐sectional view of piezoelectric microphone.Figure 7.11 Directivity of a microphone with a protection grid at different ...Figure 7.12 Noise measurements using (a) free‐field microphone and (b) diffu...Figure 7.13 Idealized diagram of vibration transducer.Figure 7.14 Transverse and longitudinal sensitivity of accelerometer.Figure 7.15 Mounting of an accelerometer to reduce cable whip noise.Figure 7.16 Effect of mass loading of an accelerometer on the vibration of a...

8 Chapter 8Figure 8.1 Tyndall's flames [2]. A long flame may be shortened and a short o...Figure 8.2 Tyndall's smoke jets [2]. The amount of shrinkage exhibited by so...Figure 8.3 Rayleigh's copy of Mayer's paper on sound intensity.Figure 8.4 (a) Arrangement of apparatus for wave calibration by means of the...Figure 8.5 Instantaneous spatial distributions of sound pressure, particle v...Figure 8.6 Sound energy and sound intensity.Figure 8.7 Spatial distributions of instantaneous sound pressure, instantane...Figure 8.8 Idealized monopole source of sound.Figure 8.9 (a) Real intensity fluctuations, (b) Imaginary intensity fluctuat...Figure 8.10 Schematic diagram of sound intensity measurements made with the ...Figure 8.11 Schematic diagram of sound intensity measurements made with the ...Figure 8.12 Microphones arrangements used to measure sound intensity.Figure 8.13 Sound intensity probe with the microphones in the face‐to‐face c...Figure 8.14 Three‐dimensional sound intensity probe for vector measurements;...Figure 8.15 Experimental set‐up for measuring sound intensity, (a) near fiel...Figure 8.16 Illustration of the error due to the finite difference approxima...Figure 8.17 Finite difference error of an ideal p–p face‐to‐face sound...Figure 8.18 Pressure increase on the two microphones of a sound intensity pr...Figure 8.19 Error of a p–p sound intensity probe with half‐inch microp...Figure 8.20 Error level Le due to a phase error φ eof 0.3° in a plane p...Figure 8.21 Coupler for measurement of the pressure‐residual intensity index...Figure 8.22 Maximum error due to a phase mismatch as a function of the bias ...Figure 8.23 The global pressure‐intensity index ∆ pldetermined under three d...Figure 8.24 Effective separation results performed by the manufacturer of th...Figure 8.25 Calibrators for calibration of sound intensity calibration in th...Figure 8.26 Sensitivity and gain adjustment using B&K calibrator 3541Figure 8.27 Phase difference determination between microphone pair using B...Figure 8.28 Use of B&K coupler UA 0914 and calibrator B&K 3541 to verify pha...Figure 8.29 Final verification steps in system calibration using free field ...Figure 8.30 Final verification check to see that the sound pressure level (F...Figure 8.31 Normalized systematic error ϕ eof a p–u system due to...Figure 8.32 A p–u sound intensity probe.Figure 8.33 Hand‐held probe for surface intensity measurement [84].Figure 8.34 Phase shift Δ ϕ xfrom the finite distance between the microp...Figure 8.35 Transducer arrangement for phase shift determination [82].Figure 8.36 Error E in intensity caused by uncorrected phase shift ϕ [8...Figure 8.37 Sound intensity measured on a segment of (a) a hemispherical mea...Figure 8.38 Typical box surface used in sound power determination with the i...Figure 8.39 Sound power level measured by sound intensity of a Caterpillar T...Figure 8.40 Indoor sound power measurement of a reciprocating compressor [90...Figure 8.41 Automated sound‐intensity system used to measure the sound power...Figure 8.42 Garden tractor used for tests of gated sound power [91].Figure 8.43 Measurements of the sound intensity radiated by a vacuum cleaner...Figure 8.44 Sound intensity vectors measured in two planes near a violoncell...Figure 8.45 Oil pan narrow‐band sound power level spectrum determined from t...Figure 8.46 Comparison of sound power level determined for the oil pan from ...Figure 8.47 Narrow‐band sound power level determined from surface intensity ...Figure 8.48 Comparison of sound power level determined for the oil pan from ...Figure 8.49 Radiation efficiency of the oil pan determined at an engine spee...Figure 8.50 Comparison of diffuse field intensities averaged over narrow fre...Figure 8.51 Experimental set‐up for measurement of transmission loss of a pa...Figure 8.52 Transmission loss of a 3.2 mm thick aluminum panel: ‐‐□‐‐...Figure 8.53 Measured and calculated transmission loss of a composite aluminu...Figure 8.54 The transmitted sound intensity measured with a probe with micro...Figure 8.55 Interlaboratory comparisons according to ISO 140‐3 for a single ...Figure 8.56 Interlaboratory comparison for a single metal leaf window (lower...Figure 8.57 Photograph of the aircraft fuselage in the semi‐anechoic chamber...Figure 8.58 Instrumentation used for the measurement of sound transmission l...Figure 8.59 Transmission loss versus frequency for the back passenger window...Figure 8.60 Sound transmission loss versus frequency for different aircraft ...Figure 8.61 Schematic diagram of the experimental set‐up for the measurement...Figure 8.62 Transmission loss of the cylindrical shell measured by two‐micro...Figure 8.63 Experimental results of radiation efficiency at one‐third octave...Figure 8.64 Layout of the packaging machine [101].Figure 8.65 Sound intensity measurement set‐up.Figure 8.66 Sound pressure measurement set‐up [101].Figure 8.67 Convergence of sound power results [101].Figure 8.68 Signal/noise ratio [101].Figure 8.69 Sound power level (SIL) results from sound intensity method. Sou...Figure 8.70 Comparison of final fixed points and scanning values, final fixe...