噪声测量之噪声对人影响

1、噪声测量之噪声对人影响 噪声噪声 测量测量 第二部分：噪声对人们的影响第二部分：噪声对人们的影响 噪声测量之噪声对人影响 1-Subjective phenomenon. Sound/noise声音声音/ /噪声的主观现象噪声的主观现象 Sound affect different people in different ways. The perception of sound is subjectively interpreted depending on the moon of each and the state of tiredness.声音以各种方式影响着人们，声音的感知主观上依赖

2、于人们自身的心理、 生理状态，愉快、疲劳 Enjoyable sound令人愉悦的声音 Unwanted sound让人反感的声音 Communication/warn交谈/报警声 噪声测量之噪声对人影响 Therefore an individual will make subjective judgment about various noises which impinge him. 因此，每个人都会对噪声作出自己的主观判断。 Sound allow human being to make quality evaluations and diagnoses. 人们可以对声音品质作出评价和

3、诊断。 How can we obtain objective measures of these subjective effects? 那么如何对这些主观影响进行客观测量呢？ Rating of the sounds in terms of annoying feelings (loudness, sharpness, roughness, tonality.) means of comparing sounds under different conditions.可以根据声音烦 恼度不同(评价参数包括: 响度、尖锐度、粗糙度、音调)或不同条件下各种声 音间的对比, 将其划分为不同等级。

4、 Measurement of the hearing damage (audiometry)测量听力损害度(听力计) Allow to reduce noise from any environment (airport, train station, factories.) 减少各种环境中的噪声(机场、火车站、工厂) 噪声测量之噪声对人影响 2-Human hearing system人类的听觉系统 Human hear responds predominantly to airborne noise = pressure changes 人耳对空气噪声的响应 =气压变化 噪声测量之噪声对

5、人影响 Pressure variation is an adequate noise measurement quantity because : 压力变化可用来充分度量噪声的原因是： The auditory system responds to pressure changes 听觉系统对声压的变化有响应 Mechanical structures responds to pressure 机械结构对压力有响应 Easiest acoustic quantity to measure. From pressure, sound intensity and power can be eva

6、luated. 可用于测量最简单的声学量。通过测量声压，可以估计出声强度和声能量。 噪声测量之噪声对人影响 3. Non linearity of the hear response人耳的非线性响应人耳的非线性响应 The auditory system sensitivity varies with frequencies 听觉系统的灵敏度会随着声音频率不同而发生变化。听觉系统的灵敏度会随着声音频率不同而发生变化。 Speech range: 200Hz-6000Hz 语音频率范围：200Hz-6000Hz Speech intelligibility range: 500Hz-4000Hz

7、 清晰语音频率范围：500Hz-4000Hz 噪声测量之噪声对人影响 Low frequencies need more “energy” or sound pressure level to be heard than sound within 1kHz-5kHz. 与频率在1kHz-5kHz之间的声音相比，低 频声音往往需要具有更高的能量或者更高 声压级时，才能被人们听见。 To take into account of the non linearity of the ear response at low Frequencies, the A-weighting curve is of

8、ten used. 通常用A计权曲线来更好地说明人耳在低 频段的非线性响应特性。 噪声测量之噪声对人影响 A weighting curve A计权曲线 FrequencFrequenc y Hzy Hz A A weighting weighting dBdB FrequencFrequenc y Hzy Hz A A weighting weighting dBdB 20-50.5800-0.8 25-44.710000 31.5-39.412500.6 40-34.616001 50-30.220001.2 63-26.225001.3 80-22.531501.2 100-19.140

9、001 125-16.150000.5 160-13.46300-0.1 200-10.98000-1.1 250-8.610000-2.5 315-6.612500-4.3 400-4.816000-6.6 500-3.220000-9.3 630-1.9 where WWA = weighting to be applied, dB f f = frequency, Hz 噪声测量之噪声对人影响 But A-weighting curve simulates the response only of the ear for low level sound. The A-weighting

10、curve follows approximately the equal loudness curve of 40phons. 但A计权曲线只能模拟人耳对低声音的响应特性。下图所示，A计权曲线约对应于40宋等响度曲线。 Each curve corresponds to the equal sensation of loudness perception for different pure tones frequencies.每条曲线都是不同频率纯音的等响度曲线。 Tone of different frequency but same SPL are not perceived equa

11、l. 声压级相同但频率不同的纯音，其对应感知度并不相同。 A tone of 10 dB 200Hz has the same loudness perception than a tone of 0 dB2kHz. 10dB 200Hz与0dB 2kHz的声音拥有相同的响度感知度。 At low level a pure high frequency tone will easily mask low frequency pure tone. 在低声压级段，高频纯音可以轻易掩蔽低频纯音。 噪声测量之噪声对人影响 Looking at these curves the noise engine

12、er task will need to decrease more SPL at high frequencies than at low frequencies to get the same subjective perception of loudness. 从曲线中可看出，为了使高频和 低频声音响度的主观感知度一 致，噪声工程师需要更多地降低 高频声音的声压级。 噪声测量之噪声对人影响 To take into account of the ear response for different level of sound several weighting has been dev

13、eloped:考虑到人耳对不同等级声音的响应，人们提出了几种不同计权方法： B-weighting curve approximately follows the 70 phons equal loudness curve B计权曲线约对应于70宋等响度曲线 C-weighting curve approximately equal loudness follows the 100 phons curve C计权曲线约对应于100宋等响度曲线 where WWB = weighting to be applied, dB f f = frequency, Hz where WWC = weig

14、hting to be applied, dB f f = frequency, Hz D-weighting curve follows a special curve which emphasizes frequencies between 1kHz-10kHz. Used for air craft applications. D计权曲线对应于一条主频在1kHz-10kHz内的特殊曲线， 主要应用于机场噪声。 噪声测量之噪声对人影响 Perception of sound pressure level variation 对声压级变化的感知度声压级变化的感知度: : Change in

15、Change in sound levelsound level Human perceptionHuman perceptionChange in powerChange in power increaseincrease Change in powerChange in power decreasedecrease 3 dB3 dBJust perceptible21/2 5 dB5 dBClearly noticeable31/3 6 dB6 dBClearly noticeable Double amplitude 41/4 10 dB10 dBHalf or twice as lou

16、d101/10 20 dB20 dBMuch quieter or louder 10 times amplitude 1001/100 Results applied for frequency around 1000Hz.以上结果适用于频率约1kHz的情况 At higher or lower frequencies much larger difference of SPL need to be applied to perceived the difference in loudness. 当声音频率明显高于或低于1kHz时，相差相同的响度对应的声压级的变化更大。 噪声测量之噪声对人影

17、响 4. Speech intelligibility 语音清晰度语音清晰度 Speech intelligibility : accuracy with which a normal listener will understand a spoken word or sentence. 语音清晰度：正常人能听清一个单词或句子时的语音精度。 Speech intelligibility depends upon the background noise in relation to the level of of spoken words. 语音清晰度由背景噪声和语音声压级之比决定。 Spee

18、ch Interference Level SIL of the interfering background noise is given by: 背景噪声对语音的干扰级定义为： Speech range语音频率范围: 200Hz-6000Hz Speech intelligibility range清晰语音频率范围: 500Hz-4000kHz 3 20001000500bandoctaveHzatSPLbandoctaveHzatSPLbandoctaveHzatSPL SIL 噪声测量之噪声对人影响 Of the background noise Possible with Norma

19、l voice Communicating voice Difficult.impossible Acceptable speech communication 可让人接受的语音交流 = 95% sentence intelligibility 95%的句子可以听清 60% word-out-context recognition 60%的单词可以辨识 Speech intelligibility depends on the reverberation of the space, sex, noise fluctuation. 语音清晰度取决于空间混响、发声人性别、噪声起伏。 For sit

20、uation where speech or telephone communication are important a maximum of 70dB(A) background. 在一些如演讲或电话交谈的重要场合， 背景噪声不要超过70dB(A)。 Expected voice level = average talkers subjective response to the background noise 期望语音等级是指谈话者对背景噪声的平均主 观响应。 噪声测量之噪声对人影响 5. Masking effect 掩蔽效应掩蔽效应 Masking effect is the p

21、henomenon of the one sound interfering with the perception of another sound. 掩蔽效应是一个声音掩盖住另一个声音，使其无法被感知的现象。 Intense tone may mask sound of speech高强度的纯音往往可能掩蔽住语音。 Low frequency tones are more effective in masking sound speech than higher tone. 低频率的纯音比高频率的纯音更能掩蔽人们的语音。 声音A被声音B掩蔽，如果A处于以B为中心的掩蔽范围内，掩蔽会更加明

22、显，这个范围叫做临界带宽。每种频率的临界带宽都不一样，频率越高， 临界带宽越宽。 噪声测量之噪声对人影响 6. Psychological effect of noise噪声的心理效应噪声的心理效应 Noise as a cause of stress :噪声是心理压力的成因之一： Effect of fear, change in pulse rate, respiration rate, blood pressure, acuity of vision 噪声可以令人感到恐惧，改变人的脉搏、呼吸频率、血压、视觉敏锐度。 Effect on behavior and work efficien

23、cy:对行为举止和工作效率的影响： Complex tasks are likely to be impaired in the presence of noise and simple tasks improved. 做复杂工作时需要较低的环境噪声，而简单工作时的环境噪声可以适当增加。 If the noise level is far excessive for a particular task, workers become irritable as well as less efficient. 过大量噪声往往使人变得急躁，同时也影响工作效率。 噪声测量之噪声对人影响 7. Nois

24、e rating NR and Noise Criteria NC curves 噪声评价曲线噪声评价曲线NRNR和噪声标准曲线和噪声标准曲线NCNC For example NR curves are intended to determinate the acceptable indoor noise level for hearing preservation, speech communication and annoyance. 例如：NR曲线被计划用于表征室内可接受的噪声等级，以便于听力保护、会话交谈、烦 恼度评价。 These curves mean that in no fre

25、quency band shall the octave band sound pressure (in the specified space) exceed the NR or NC value. 这些曲线表明，在任何频带，倍频程带的声压(指定空间中)都不会超过NR或NC值。 They intend for specifying an upper bound of acceptability for background noise. 这些曲线计划用于详细说明背景噪声的可接受上限。 NC was originally developed in response to the need fo

26、r specification of just acceptable air conditioning noise. NC曲线最初是用来控制可接受空调噪声的需要。 噪声测量之噪声对人影响 First measure the sound pressure level spectrum. Apply it on the NR Curves diagram and evaluate the NR of the noise under investigation. 首先测量出声压级谱，并将其应用在NR曲线图上，通 过研究分析，估计出噪声的NR值。 The NR is determined by the

27、 highest weighting curve which just envelopes the data. NR值主要由超过最大频率值的加权曲线决定。 The machine exhibits a NR of 80. 这个机器显示的NR值是80。 噪声测量之噪声对人影响 Noise rating curve Application NR 25 Concert halls, broadcasting and recording studios, churches NR 30 Private dwellings, hospitals, theatres, cinemas, conference

28、 rooms NR 35 Libraries, museums, court rooms, schools, hospitals operating theaters and wards, flats, hotels, executive offices NR 40 Halls, corridors, cloakrooms, restaurants, night clubs, offices, shops NR 45 Department stores, supermarkets, canteens, general offices NR 50Typing pools, offices wit

29、h business machines NR 60Light engineering works NR 70Foundries, heavy engineering works Type of Room - Space Type Recommended NC Level Equivalent Sound Level NC CurvedBA Apartments25-3535-45 Assembly Halls25-3035-40 Churches30-3540-45 Courtrooms30-4040-50 Factories40-6550-75 Hotels/MotelsHotels/Mot

30、els - Individual rooms or suites25-3535-45 - Meeting or banquet rooms25-3535-45 - Service and Support Areas40-4545-50 - Halls, corridors, lobbies35-4050-55 OfficesOffices - Conference rooms25-3035-40 - Private30-3540-45 - Open-plan areas35-4045-50 - Business machines/computers40-4550-55 Hospitals an

31、d ClinicsHospitals and Clinics - Private rooms25-3035-40 - Operating rooms25-3035-40 - Wards30-3540-45 - Laboratories35-4045-50 - Corridors30-3540-45 噪声测量之噪声对人影响 噪声测量之噪声对人影响 8. Room Criteria RC curves室内标准室内标准RCRC曲线曲线 The NR and NC are not defined for very low frequencies (rumble noise) and they are

32、too permissive in the frequency range of 2000 Hz and higher octave bands. NR和NC曲线低频噪声段没有定义，而只绘制了频率在2kHz或更高倍频程带时的值。 Creation of RC curves :RC曲线的产生： To include low frequencies包含低频成分 To specify desirable noise levels within non industrial interior spaces.定义非工业噪声领域 中的室内期望噪声等级 To introduce acoustic “perf

33、ume” 了解声学”特性” 噪声测量之噪声对人影响 噪声测量之噪声对人影响 Nature of the sound under measures :所测噪声种类： Steady noise : average of the sound level pressure 稳定噪声：平均声压级。 Fluctuating or cyclic noise : equivalent continuous noise level must be evaluated. 起伏或周期噪声：必须评估等价连续噪声等级。 噪声测量之噪声对人影响 The source of noise is characterized b

34、y its frequency contents and any control of it must be done accordingly.频率成分是声源的特征，是一切控制手段的依据。频率成分是声源的特征，是一切控制手段的依据。 Noise reduction performance can not be specified independently of source frequencies. 不研究声源的频率特性，减振降噪工作就无从谈起。 20 HzAudible range20kHz20 HzAudible range20kHz 20 Hz20 Hz听觉范围听觉范围20kHz80d

35、B(A) causes listener to incur a partial dose of noise. 噪声剂量：暴露在任何声压级大于80dB的噪声中，听者会招致部分剂量噪声影 响。 T in hour L in dB 5 90 2 8 L T 噪声测量之噪声对人影响 TWA is the sound level that would produce a given noise dose if an employee were exposed to that sound level continuously over an 8 hour work day. TWA是当工人在8小时工作日内

36、连续暴露在某个声压级时所产生的确定噪 声剂量。 A noise dose of 50% (TWA=85dB(A) is point at which employee must implement continuing hearing conservation program which includes exposure monitoring, audiometric testing, hearing protection, employee training and record keeping. 目前，我国政府部门要求从事TWA在85dB以上职业者需要听力保护，如： 噪声监听、听力测试、

37、听力保护等。 噪声测量之噪声对人影响 9.7 Noise dose for impulse noise and impact noise 脉冲噪声和冲击噪声的噪声剂量脉冲噪声和冲击噪声的噪声剂量 The human ear has an excellent recuperation between different impulses. Increasing the noise level by 5dB will double the noise dose. The noise dose also depends on the number of impulse during an 8 hou

38、rs shift. 声压级每增加5dB，噪声剂量增加1倍。噪声剂量同样依赖于8小时内的脉冲噪声数。 The equivalent noise dose depends on: Duration of each impulse or impact noise time the number of impulses or impact noises Corresponding peak pressure level 噪声剂量依赖于脉冲噪声和冲击噪声的持续时间和数量，与声压级峰值相关。 噪声测量之噪声对人影响 10. Sound quality metrics 声音品质 Several functi

39、ons exist to give a quantification of the human perception of sound and its subjective description. 多个函数都可以对声音感知度作出定量评估和主观描述。 10.1 Loudness响度 Loudness (in phons or sones): describes the sensation of loudness (sound level) of a sound. 响度(单位：方或宋)：描述人耳感觉到声音的强弱等级。 As already seen : tones of different fr

40、equency but same SPL are not perceived equal in terms of loudness. to compare loudness of a sound a tone of 1kHz has been taken as reference. 频率不同，但声压级相同的纯音，其响度并不相同。 通常以1kHz纯音的响度作为基准，以便于比较。 60 phons means as loud as a 60dB, 1000 Hz tone60 phons means as loud as a 60dB, 1000 Hz tone 60phons60phons等同于

41、等同于1kHz1kHz，60dB60dB单音的响度单音的响度 噪声测量之噪声对人影响 The use of the phon as a unit of loudness is an improvement over just quoting the level in dB, but it is still not a measurement which is directly proportional to loudness. The sone scale was created to provide such a linear scale of loudness. It is usually

42、 presumed that the standard range for orchestral music is about 40 to 100 phons. If the lower end of that range is arbitrarily assigned a loudness of one sone, then 50 phons would have a loudness of 2 sones, 60 phons would be 4 sones, etc. 与用分贝表示响度级相比，单位phon的使用是一大改进。但它与响度仍然没有直接的比例关系。所以又 创建了单位sone，它与

43、响度有直接的比例关系。通常认为标准管弦乐的响度范围约为40-100phons.如果 上述响度范围的下限设为1sone，则50phons相当于2sones，60phons相当于4sons，以此类推。 Dynamic LevelPhonsSones fff 10064 . 90 32 f 8016 . 708 p 604 . 502 ppp 40 1 The sone scale has the advantage that it is a linear function of the human sensation: 2 sone tone is Perceived twice as loud

44、as a 1sone tone. 量级sone的优点在于，它是人感知度的线性函数：响度为 2sone的单音，其感知度正好是1sone单音的两倍。 The level of a 1kHz tone has to increase by 10dB in order to enlarge the sensation of loudness by 2. 1kHz的单音，为使人耳响度感知度提高一倍，声压级需增 大10dB。 噪声测量之噪声对人影响 10.2 Sharpness (acum) 尖锐度尖锐度(acum)(acum) Sharpness (in acum) is defined as the

45、ratio of high frequency level to overall level. Sounds that have higher energy in high frequencies tend to be sharper. (cry of a little girl.) 尖锐度定义为所有声音中高频成分所占的比率，能量集中在高频部分的声音听起来会比较尖锐。 Sharpness is particularly suitable for the idle noise due to the high frequency content. An example of this phenom

46、enon is a ball bearing type drive of poor quality. Minor imperfections in the surface of the balls will result in discrete tones at multiples of the rotational speed, commonly referred to as bearing defect frequencies. 尖锐度尤其适用于评价由高频成分引起的怠速噪声。低质量的球轴承驱动装置所发出的噪声就 是其中一例。轴承中球状铁珠的较小缺陷也会导致在多个转动速度时，发出离散的噪声，

47、通常 称为轴承缺陷频率。 The sharpness is determined from narrow-band sound pressure spectrum. Therefore, spectral contents and the center frequency of the narrow band sounds are important for sharpness analysis. 尖锐度由窄带声压谱决定。因此，在尖锐度分析中，窄带的谱结构和中心频率很重要。 噪声测量之噪声对人影响 The reference sound producing 1 acum is a narrow

48、-band of the centre frequency of 1 kHz. 参考声源产生的1acum声音是中心频率为1kHz的窄带声音。 Sharpness of a sound is correlated with annoyance. 声音的尖锐度与烦恼度有关。 For a broad band noise: if the lower cutoff frequencies contents increase then the sharpness decreases. if the upper cutoff frequencies contents decrease then the s

49、harpness decreases. 对于宽带噪声：当宽带截止频率下限增大时，尖锐度降低。当宽带截止频率的上限 减小时，尖锐度升高。 Problem : no standardization for sharpness : Bismark or Aures methods. 问题：尖锐度还未标准化： Bismark 或 Aures法 噪声测量之噪声对人影响 Illustration of a sound signal with (a) steady amplitude and (b) amplitude that fluctuates over time. 10.3 Roughness (a

50、sper)/ Fluctuation strength (vacil) 粗糙度粗糙度(asper)(asper)起伏强度起伏强度(vacil)(vacil) Roughness and fluctuation strength quantify the subjective perception of amplitude or frequency modulation. 粗糙度和起伏强度可定量表示振幅或频率调制下的主观感知度。 Amplitude fluctuations describe variations in the maximum value (amplitude) of sound

51、 signals relative to a reference point and are the result of wave interference. The interference principle states that the combined amplitude of two or more vibrations (waves) at any given time may be larger (constructive interference) or smaller (destructive interference) than the amplitude of the

52、individual vibrations (waves), depending on their phase relationship. 振幅起伏描述了声波振幅最大值与参考值之间的变化，其起因是声波的干涉。干涉法则表明，任意给定时刻，两个 或多个振动(声波)相叠加后的振幅可能或大于(相长干涉)或小于(相消干涉)每个单一的振动(声波)的振幅，其大小取决 各振动相位之间的关系。 In the case of two or more waves with different frequencies, their periodically changing phase relationship re

53、sults in periodic alterations between constructive and destructive interference, giving rise to the phenomenon of amplitude fluctuations. 当两个或多个不同频率声波相互叠加时，其周期性的相位变化会导致叠加后的声波周期性地交替产生相长或相消干 涉，于是形成了振幅起伏的现象。 噪声测量之噪声对人影响 Rate of fluctuation will define the type of modulation encounter : 起伏率定义了调制交会类型。 Ro

54、ughness is the subjective perception of rapid (15-300 Hz) amplitude modulation of sound. 粗糙度描述了对声波快速(15-300 Hz)振幅调制的主观感知度。 Fluctuation strength quantify the subjective perception of slow (20 Hz) amplitude modulation of sound (beating). 起伏强度定量描述了对声波慢速(20 Hz)振幅调制的主观感知度(如敲打)。 Amplitude fluctuation degr

55、ee: (=degree of modulation) the level difference between peaks and valleys in a signal such as the one in Figure 1b. The degree of amplitude fluctuation depends on the relative amplitudes of the components in the signals spectrum. 振幅起伏度：(调制度)表示波峰和波谷间的差分等级，如图1b。振幅起伏度由信号谱中各组成 成分的相对振幅决定。 If the interfe

56、ring tones are of equal amplitudes then it will result the highest fluctuation degree and therefore in the highest roughness degree. 若相干音调具有相同的振幅，则结果的起伏度最大，同时导致粗糙度也最大。 Frequency deviation is the difference between the two frequencies of the signal and its modulated. 频率偏差表示信号中两个频率及调制度间的差别。 噪声测量之噪声对人影

57、响 Roughness 粗糙度粗糙度 Roughness of 1 asper = 1 kHz tone of 60dB 100% modulated in amplitude with a modulation frequency of 70Hz. 粗糙度1asper频率1kHz，声压级60dB纯音，经100%的振幅调制，调制频率为 70H时，产生的粗糙度。 Fluctuation strength 起伏强度起伏强度 Fluctuation strength of 1 vacil = 1kHz tone of 60dB 100% modulated at 4Hz. 起伏强度1vacil频率1

58、kHz，声压级60dB，经100%调制，调制频率为4Hz时， 产生的起伏强度。 噪声测量之噪声对人影响 10.4 Prominence ratio 显著率显著率 Sound with tonal components are very annoying. Prominence ratio and tonality find and display tonal components of a signal. 不同音调混在一起的声音是烦人的。显著率和调性有助于发现和显示一个信号的音调组成。 The method is described in the standard ECMA-74 “Measu

59、rement of airborne noise emitted by information technology and telecommunication equipment”. 标准ECMA-74“信息技术和无线电通讯设备所发射噪声的测量方法”中介绍了具体的方法。 A discrete tone which occurs together with broadband noise is partially masked by that part of the noise contained in a relatively narrow frequency band, called the critical band, that is centered at the frequency of the tone. Noise at frequencies outside the critical band does not contribute significantly to the masking effect. The width of a critical