运用神经网络推算音乐厅满场混响时间

混响时间是厅堂音质评价中的一个重要客观参量。本文提出了运用神经网络由空场混响时间推算满场混响时间的新方法。与其它方法比较,该方法有相当的预测精度。在此基础上,本文进一步分析了音乐厅中座椅类型和座椅数量对满场混响时间的影响,并对满场条件下座椅的吸声增量进行了讨论。     

L.L.Beranek教授访问我国

世界著名声学家L.L.Beranek教授应魏荣爵院士邀请,在南京大学百年校庆学术报告会（2002年5月22日）上作了“音乐厅和歌剧院”的报告。白瑞纳克教授在会前和会后访问了北京和上海,分别在中国科学院声学研究所和同济大学作了“音乐厅音质的客观参量”和“音乐厅和歌剧院”等学术报告。介绍了他的丰富设计经验和卓越研究成果。并在同济大学举行他的名著《音乐厅和歌剧院》中文版首发式（王季卿、戴根华、项端析、郑敏华等译,同济大学出版社出版）。该书从音乐、声学和建筑三个方面探讨大厅音质最新进     

音乐厅音质综合评价

通过综合许多厅堂音质专家的意见，本文建议一个更为完整的评价厅堂音质的因子集和较为合理的隶属度函数以便用于音乐厅音质的模糊集综合评价。所建议的因子集包括混响时间ＲＴ，合奏强音乐段的平均声压级ＬｐＦ，侧向效率ＬＥ，早期衰减时间的频率特性｜ＥＤＴ（ｆ）｜，以及音乐厅中１０ｌｇＬＥ值的极差Ｖｍａｘ（１０ｌｇＬＥ）。本文通过一个实例来表明综合评价的具体过程。可看出将模糊集方法应用于音乐厅音质的综合评价是可行的，因为它可以在模糊评估的基础上给出一个定量的评价结果。     

关于音乐厅响度评价的研究

该文回顾并综述了对音乐厅(包括西洋交响乐厅及中国民族音乐厅)响度评价的研究历程,指出采用乐队齐奏强音标志乐段的平均声压级L_pF作为评价音乐厅响度客观指标的合理性与可行性。文中给出L_pF的计算方法以及对若干厅堂计算值与实测值的比较,并通过主观评价,给出L_pF的初步优选值域。采用L_pF作为响度评价指标的好处不仅在于它能表征听众听到的绝对响度的感受,还在于能预判何种规模的乐队适于在多大规模的音乐厅中演出,以便达到较佳响度效果的问题。     

章奎生先生去世

正章奎生先生1937年12月19日生于浙江上虞,1958年9月至1962年7月就读于同济大学建筑物理专业。1962年10月进入华东建筑设计研究院工作,先后任技术员、工程师、主任工程师、高级工程师、教授级高工。2000年成立章奎生声学设计研究所并任所长,2014年创办上海章奎生声学工程顾问有限公司并任董事长,2021年3月21日去世,享年83岁。章奎生先生是我国著名的建筑声学实践家。他在我国的建筑声学工程领域留下了众多青史留名的作品,以上海大剧院为代表的"中国十大剧院"6座出自章奎生先生及其团队。上海大剧院也是中国唯一被世界著名声学家白瑞纳克博士编入《音乐厅与歌剧院》一书的剧院。鉴于其在建筑声学届的卓越贡献,章奎生先生被业内誉为"建声泰斗"。     

全国厅堂音质研讨会在宁波召开

由中国声学学会环境声学分会和中国建筑学会建筑物理委员会、北京声学学会联合召开的全国厅堂音质研讨会于1989年11月1日至3日在浙江宁波举行。来自全国有关厅堂音质的研究和设计部门共23名代表,在会上宣讲了15篇厅堂音质的研究成果和设计经验文章,并重点研讨了以下四方面的问题: 1.国内外影剧场音质研究、设计的经验教训和音质指标; 2.新技术(方法)在厅堂音质研究、设计中的应用;     

音乐厅声学

本文提出了音乐厅设计中的各项重要参数;讨论了若干设计良好的新的和老的音乐厅,包括波士顿交响音乐厅为什么如此成功伟大;深入地分析了纽约林肯中心Philharmonic音乐厅中出现的问题;最后还讨论了欧洲和日本在这方面的最新研究结果。     

厅堂中混响时间测量的一些实际问题

本文根据多年来在一些大厅中进行混响时间测量(空场和满场)的经验,以及利用不同声源所积累的资料,分析了测量的误差.由于记录读数误差导致的混响时间的变异系数可控制在5％左右,而由于厅内声场不均匀性所引起的变异系数则在10％左右.至于利用不同声源所得结果之间的偏差则往往小于上述的误差范围,因此它们的差异并不显著.比较时所用声源有乐队、白噪声、啭音、发令枪声和气球的爆破声.本文还指出,在某些厅堂中测得的混响时间重复率较低,类似情况或更严重者(相差达50—100％)在文献中亦有报导,值得注意.因此,制订规范化的测量方法也就非常必要.为模拟厅堂满场条件的声学特性,曾利用棉衣代替观众进行了混响时间的比较性测量,结果基本上一致.     

模糊数学在厅堂音质评价中的初步应用

本文首先简要分析了目前厅堂音质评价常用的方法及其中存在的一些问题;然后给出了用模糊关系方程和分组法求加权系数和综合评判的数学模型,并用此对我国一些已有的厅堂音质调查结果作了分析;最后指出了厅堂音质中应用模糊数学的意义及关于今后研究的一些想法。     

日本新建两大厅堂项目

１东京国家剧院占地４４０００ｍ２;于１９９７年９月开幕．内有１８００座的歌剧院,１４５００ｍ３,满场混响时间１．５ｓ;１０３８座的小剧场,７２００ｍ３,满场混响时间１．１ｓ;１６３６座的音乐厅,１５３００ｍ３,满场混响时间１．９５ｓ．各厅尚有ＥＤＴ,ＢＲ,ｔ;ＩＡＣＣ;Ｃ８０和噪声等多项测量指标．该项工程于１９８５年开始建筑设计国际竞赛,日本ＴＡＫ设计事务所获奖．声学顾问由美国Ｂｅｒａｎｅｋ和ＴＡＫ联合进行．设计中利用了多种手段,前后化了７年时问,并写出多篇声学论文发表．２东京国际论坛一座当今最…     

Relation of acoustical parameters with and without audiences in concert halls and a simple method for simulating the occupied state

Five acoustical parameters-reverberation time RT, early decay time EDT, clarity C80, strength G, and interaural cross-correlation coefficient IACC-were measured using identical procedures with and without audiences in six concert and opera halls. Reverberation times without audiences were measured in 15 additional halls using the same measuring techniques as for the six halls above, but for full occupancy the data were taken from musical stop chords at symphonic concerts. This paper shows that in all halls (1) the occupied RT can be predicted from the unoccupied RT using a linear regression equation, y = a - b exp(x), within acceptable limits, at low- and mid-frequencies. It is also shown for the six halls that (2) occupied C80's are predicted accurately from unoccupied values by the newly proposed equation; (3) G's with and without audiences are highly correlated by a first degree linear regression equation; and (4) IACCs have nearly the same value in both occupied and unoccupied halls. As a separate subject, the successful use of a cloth covering for seats in a concert or opera hall to simulate the occupied condition has been developed.     

Taking account of loudness constancy for the loudness criterion for concert halls

One of the surprises from analysis of results of an objective and subjective study of British concert halls (1988 Acustica 66, 1–14) was that the subjective judgement of loudness in concert halls is influenced not only by sound level but also by the source–receiver distance. This response implies that the same sound level is judged louder at positions further from the orchestra platform. Whereas level decreases with distance in actual halls, loudness is judged more-or-less independent of position in average halls (except at positions close to the platform and seats overhung by balconies). As an observation it ties in with evidence from experimental psychologists for loudness constancy throughout a space. The sound strength G is the sound level in an auditorium normalised to the sound power level of the source; the traditional criterion of acceptability for level is that G ? 0 dB. The paper proposes that, on the basis of subjective evidence and objective behaviour in auditoria, the criterion for G should not be a unique value of G but rather a function of source–receiver distance.     

Wall diffuser designs for acoustical renovation of small performing spaces

This paper investigates the material characteristics of diffusers for acoustical renovation of existing small performing spaces. Consideration is given to acoustical effects on sound fields through the practical cases of two performing halls: the Chamber Hall (450 seats) and the M-Theater (630 seats) in the Sejong Performing Arts Center, Seoul. The Chamber Hall was completely refurbished into a recital hall from its previous shape of a rectangular conference space. The saw-tooth shaped wall diffuser profile in the Chamber Hall was designed using glass-fiber reinforced concrete for mid-frequency sound diffusion. The M-Theater was renovated as a live and intimate space for dramatic performances with a design that included more seats on the upper floors and additional spaces above ceiling reflectors. The vertically-patterned diffuser profile with protruded cubic surfaces in the M-Theater was designed using glass-fiber reinforced gypsum for sound diffusion in the major speech frequency range. Designed diffuser profiles were evaluated for both halls by measurements of scattering and diffusion coefficients of the 1:10 scale model diffusers. The effects of diffusers in both halls were also investigated by covering the lateral walls close to the stages with reflective materials to control diffusive surfaces. As a result, spatial uniformity increased with diffusive wall profiles in both halls.     

音乐厅音质设计进展述评

本文对近年来音乐厅音质设计中若干问题的进展作一述评。（1）在已建立的众多独立音质参量基础上，如何作出大厅综合评价，就需要考虑到它们的互动性和贡献权，方法学将成为关键。（2）空间感已确认由声源视在展宽度ASW和听者环绕感LEV组成，对于影响两者的诸多复杂因素有了较深入研究，这声场中的细节又将如何与大厅设计相联系亦备受关注。（3）听众及座椅吸声这个老问题有了新的研究成果，对于空、满场的声学关系已积累了更多资料，使大厅音质的估算更为精确可靠。（4）常说扩散对大厅音质很重要，但其主观效应仍然处于玄虚状态，一些新的主观试听实验结果还不足以说明问题。     

Review of objective room acoustics measures and future needs

ISO 3382-1 describes a number of objective room acoustics parameters that are generally accepted as useful for rating some specific aspects of concert hall sound fields. They include measures of decay times, energy ratios, measures of sound strength and several quantities related to the spatial aspects of sound fields. In most cases there are details of the measures, or their application, that raise questions. In general, there has not been a lot of practical research to explore how best to develop and use these objective measures to evaluate conditions in concert halls. For some well established measures such as Early Decay Time (EDT), we are not really sure how best to calculate their values. For other measures such as energy ratios, modifications are often proposed but without the support of subjective evaluations of the proposed changes. In other cases, such as measures of spatial impression, two approaches have been suggested, but their relative merits are not well understood. It is easy to propose ever more complex measures, but it is much more difficult to demonstrate their general utility. On the other hand, some commonly described characteristics do not have accepted related objective measures. Many more important and more general problems relate to the need, for design criteria in terms of each quantity, and for an improved understanding of just noticeable differences for each measure. This paper discusses each measure illustrating particular problems with measurements in various halls.     

The acoustics of the caves

This work shows the acoustic measurements realized at three underground places: the caves of Pertosa or of the Angel, the caves of Castelcivita and the caves of Castellana. These places are used for some years to represent music and theater performances, whose success is also due to the mystery and the charm that distinguish them, based on the natural setting of the caves. The places of the caverns where the shows are played were characterized analyzing the monaural acoustic parameters (T₃₀, EDT, C₈₀, D₅₀ and Rasti) obtained with the impulse response resulting from blowing up some balloons inside them. The values of monaural acoustic parameters measured in the caves can be compared with the parameters of the concert halls currently in use.     

A group of objective acoustical criteria for concert halls

To establish a definite list of the most important objective criteria for concert halls is not easy, but it is suggested that a group of four or five criteria may be sufficient to characterise, in general, the ‘acoustics’ of a specific hall. Comparing various concert halls by means of their measured objective criteria indicates that a rather simple method of ranking is feasible.