Lesson 19 High Fidelity Audio.ppt

Unit7Audio Voice Lesson19HighFidelityAudio Lesson19HighFidelityAudio VocabularyBackgroundsTexttour Vocabulary Featureindictionary Anyofthedistinctpartsoftheface astheeyes nose ormouth 面貌特征Aprominentordistinctiveaspect quality orcharacteristic特征afeatureofone spersonality afeatureofthelandscape Themainfilmpresentationatatheater 正片Aspecialattractionatanentertainment 特别节目Aprominentorspecialarticle story ordepartmentinanewspaperorperiodical 特写Anitemadvertisedorofferedasparticularlyattractiveorasaninducement特色awashingmachinewithmanyfeatures Featureindictionary Togivespecialattentionto display publicize ormakeprominent 展示Tohaveorincludeasaprominentpartorcharacteristic 由 主演Theplayfeaturedtwowell knownactors Todepictoroutlinethefeaturesof 刻画 Featureintext AsshownbythegeometryinFig 7 1 theCDstoresabout1bitper m 2 correspondingto1millionbitsper mm 2 and15billionbitsperdisk Thisisaboutthesamefeaturesizeusedinintegratedcircuitmanufacturing andforagoodreason 从图7 1显示的几何尺寸可以看出 CD每平方微米存储1位信息 相当于每平方毫米1百万位 共存储1 5亿位信息 这个尺寸 1平方微米 和集成电路制造中的特征尺寸大致是相同的 Featureinuse acousticfeature声学特征agefeature年龄特征designfeature设计特点 Complyindictionary Toactinaccordancewithanother scommand request rule orwish 遵从Thepatientcompliedwiththephysician sorders Complyintext Thishastheadvantageofreducingtheerrorrateduetotheopticalpickup buthowdoyouforcethebinarydatatocomplywiththisstrangebunching 这样做的好处是降低了光学读取造成的错误率 但是 如何让二进制数值遵循这种奇怪的安排 Artificialindictionary Madebyhumanbeings producedratherthannatural 人工的Broughtaboutorcausedbysociopoliticalorotherhuman generatedforcesorinfluences 人为的anartificialeconomicboom Madeinimitationofsomethingnatural simulated 模拟的Notgenuineornatural 假的anartificialsmile Artificialintext Musicplayedthroughamonaural onechannel systemoftensoundsartificialandbland Incomparison agoodstereoreproductionmakesthelistenerfeelasifthemusiciansareonlyafewfeetaway 单声道系统播放出来的音乐往往听上去生硬而又平淡 相比之下 一个好的立体声音响系统会使听者感到似乎演奏家们只有几步之遥 Reproduceindictionary Toproduceacounterpart animage oracopyof 复制Togenerate offspring bysexualorasexualmeans 生殖Toproduceagainoranew re create 再生产Tobring amemory forexample tomindagain 重现 Reproduceintext Ratherthanjustmatchingtheabilitiesofthehumanear thesesystemsaredesignedtoexceedthelimitsofhearing It stheonlywaytobesurethatthereproducedmusicispristine 这些系统不是设计得刚好满足人类的听觉需求 而是超越了人类听觉的极限 这是唯一能够确保再现音乐无任何失真的方法 Reproduceinuse accuratecolourreproduction精确彩色重现datareproduction数据复制frequencyreproduction频率再生hi fireproduction高保真重放imagereproduction图象再现multichannelreproduction多声道放音signalreproduction信号再生 Secondaryindictionary Ofthesecondrank notprimary 第二的 不是主要的Inferior 低等的Minor lesser 不重要的 次要的Derivedfromwhatisprimaryororiginal 间接的asecondarysource asecondaryinfection Secondaryindictionary Havinganinducedcurrentthatisgeneratedbyaninductivelycoupledprimary Usedofacircuitorcoil 产生感应电流的Oforrelatingtoasecondaryschool 中学的secondaryeducation Secondaryintext Audiophilesdemandtheutmostsoundquality andallotherfactorsaretreatedassecondary 高保真音响爱好者对声音质量要求极高 而把除此以外所有其他因素都视作第二位 Secondaryinuse secondaryeducation中等教育secondaryproduct副产品asecondarycause次要原因secondaryinfection继发感染 TerminologyAudiophile高保真音响爱好者Hearing听力 听觉Microscope显微镜Phonograph留声机 Backgrounds TerminologyRpm revolutionsperminute转数 分scanningvelocity扫描速度Playback录音重放featuresize特征尺寸 Backgrounds Terminologyblockdiagram框图look uptable查找表Reed Solomoncoding里德 索罗蒙编码 Backgrounds TerminologyBesselfilter贝塞耳滤波器sin x xcorrectionsin x x校正 Backgrounds Texttour OutlineIntroduction para 1 CDplaybacksystem para 2 8 Stereo para 9 10 Introduction Digitalaudiowasbroughttotheworldbythecompactlaserdisc orCD Thiswasarevolutioninmusic thesoundqualityoftheCDsystemfarexceedsoldersystems suchasrecordsandtapes CDplaybacksystem thesurfaceofacompactlaserdiscthedigitalinformationstoredasaseriesofdarkpitsburnedonthesurfacewithalaserDuringplayback anopticalsensordetectsifthesurfaceisreflectiveornonreflective generatingthecorrespondingbinaryinformation CDplaybacksystem EFMtwo levelReed Solomoncodingmultiratetechnique CDplaybacksystem Figure7 1Thesurfaceofacompactdisc CDplaybacksystem Figure7 2TheblockdiagramofatypicalCDplaybacksystem Stereo Audiosystemswithmoret