SRS虚拟环绕声处理及功放系统设计

中文摘要-I-摘要随着现代视听技术的发展，出现了各类各样的影音系统。在我国，视听设备、行业在近些年得到了飞速发展，大众化的产品从无到有，产品的价格和成本大幅度地下降。家庭影院日益普及，丰富了广大人民群众的文化生活，提高了生活质量。传统的立体声系统大多是双声道的，只能保持声音的部分空间分布特性，为听众提供二维的平面分辨能力，无法再现三维的空间音响效果。尽管多声道环绕声的出现有效地解决了这一问题，但这种系统需要特制的节目源，对重放设备和听音环境的要求严格，使它的应用受到了限制旷有鉴于此，人们提出了虚拟环绕声的理论，并围绕它进行了多方面的研究。，对两声道虚拟环绕声系统的研究是本文的目的所在。在文中，我们首先介绍了声像定位理论，分析了优先效应、耳廓效应、ITD、I／D、头部相关传递函数、反射与混响等因素对听觉定位的影响，跟着对用两只音箱虚拟空间声源的技术进行了理论分析和推导，对音箱的串音消除技术作了比较深入的探讨。我们也比较了不同类型的虚拟环绕声系统，将重点放在了对SRS--3D技术的研究上。通过对SRS--3D系统原理和结构的分析，提出了一种设计该系统的关键部分——频率补偿网络的方法。为了确认所提方法的可行性，我们通过计算机用MATLAB作了模拟实验，得到了比较理想的听觉效果。而且我们用SRS音频处理芯片设计了具体的电路，与计算机模拟的结果进行了对比分析，证明了我们所提方法的实用性。虚拟环绕声系统通过对人的听觉心理特性的模拟，利用一对音箱就能在普通音源的重放中实现三维环绕声。这类系统结构简单，也能达到一定的听觉效果，在居室较为狭小的家庭或不宜采用多通路系统的场合(如多媒体计算机)具有相当广泛的应用前景。关键词：虚拟环绕声头部相关传递函数声音恢复系统串音消除混响-II-AbstractVariouskindsofAVsystemscameoutwiththedevelopmentofmodernvideoandaudiotechnologies．Havinggainedagreatimprovementduringtherecentyearsinourcounty,AVindustrysuppliedmanypopularcommodities．ThepriceandcostofAVequipmentsdecreasedgreatlyandAVsystemsenteredgeneralfamliesrapidly,whichenrichedpeople’Sculturemovementsandimprovedtheirlifequalities．Traditionalstereosystemsgenerallyhaveonlytwochannels，asaresulttheycanrepresentthespatialdistributionofsoundfieldpartly,andreproducea2Dratherthan3Dhearingeffect．Multi-channelsurroundsoundsystemscomeabouttosolvethisproblem,butthiskindofsystemrequiresthesoundsourceprogramtobetreatedspecially,alsoithassevererestrictstohardwareandcircumstance，alloftheserestrainitsapplication．Inviewofthissituation，peoplebringaboutthetheoryofVirtualSurroundSound(VSS)andcarryaboutmanyresearches.Itisjustthepurposeofthisthesistoexplorethedual—channelvirtualsurroundsoundsystems．Thethesisfirstintroduceshumansoundlocationtheory,analyzingthecuesofPrecedenceEffect，PinnaEffect，1TD，IID，HeadRelatedTransferFunction，reflectionandreverberation．Thenwecarriedaboutresearchonthetechnologyofvirtualizingsoundsourceusingtwoloudspeakers，anyexploredthecrosstalkcancelationtechnologydeeply．AftercomparingdifferentkindsofVSSsystems，weplacedouremphasisontheaspectofSRS--3Dtechnology．ThroughanalysisonSRSsystem’Sprincipleandconfugration，weputforwardamethodofdesigningthepivotalfilter(PerspectiveNetwork)．Toconfirmthefeasibilityofthismethod，wemadesomeexperimentsoncomputerusingMATLABandgotrathersatisfyingeffects，AlsowedesignedapracticalcircuitusingSRSaudioprocessIC，comparedtheresultswithcomputersimulationandtestifiedourmethod’Spracticability．Throughsimulationtohumans’spatialhearingcharacteristics，VSSsystemCanreproducenormalsoundsource’S3Dsurroundeffectusingapairof-III-loudspeakers．Thiskindofsystemhassimpleconfigurationandcanproducequitelifelikesense，soitmaybehaveanextensiveapplicationinsmallroomfamiliesorcircumstancesnotsuitformulti-channelsurroundsystems(suchasmultimediaPC)．Keywords：VirtualSurroundSoundHeadRelatedTransferFunctionSoundRetrievalSystemCrosstalkCancelationReverberation目录-IV-目录摘要..........................................................................................................IAbstract........................................................................................................II目录........................................................................................................IV第一章绪论...................................................................................................11．1引言......................................................................................................11．2环绕声技术的发展...............................................................................11．2．1杜比专业逻辑环绕声系统...........................................................31．2．2杜比数字环绕声系统...................................................................41．2．3DSP环绕声系统..........................................................................41．2．4两通路虚拟环绕声系统...............................................................51．3虚拟环绕声系统的简介.......................................................................61．4本文的主要内容...................................................................................7第二章两通道虚拟环绕声系统的原理及数学模型......................................82．1声像定位理论.......................................................................................82．1．1优先效应和耳廓效应...................................................................82．1．2ITD和IID...................................................................................102．1．3头部相关传递函数(HRTF).........................................................132．1．4反射与混晌................................................................................162．2虚拟环绕声系统的分类.....................................................................212．2．1听觉传输立体声系统.................................................................212．2．23D准虚拟环绕声系统...............................................................222．2．3多通路环绕声的虚拟重发.........................................................23目录-V-2．3虚拟处理技术.....................................................................................232．3．1原理分析...........................................................................