Therearemanydifferentfeaturesofpsychoacoustics,whichishowthebrainreceives,perceives,andinterpretssound.Iwillbegoingintodepthinthephysicsofsound,theprinciplesofmusicalinstruments,themechanismsofhumanhearing,andtheacousticcharacteristicsofspaces.

Soundisomnidirectional,meaningthesoundenergyisequallydispersedacrossamediumandsounddoesn’tcomefromonedirection.Althoughitisomnidirectional,weareabletotellwherethescenarioiscomingfrom,duetothecompressionandrarefactionofthewaveforms,andhelpfromthereflectionsintheroom.Forexample,whensomeoneclaps,theyessentiallyincreasetheamountofairmolecules,whichgivestheinitialsound.However,becausetherewasanincreaseinairmolecules,thenextareainthemediumdoesn’thaveasmanyairmolecules.Below,wecanseethisinavisualrepresentation.Wheretherearemoreairmoleculesitiscalledcompression,andthefewermoleculesiscalledrarefaction.Inmusicalterms,thisisrepresentedinwaveforms.Therearemanydifferent

characteristicstowaveformsthatchangetheoverallsound.Forexample,theamplitudeistheintensityofthecompression.Thiswillresultinanincreaseinvolume,ordecibels.Additionally,thewidthofeachwavelengthwill

resultinanincreaseinvolume,ordecibels.Additionally,thewidthofeachwavelengthwillchangethefrequency.Firstly,awavelengthisthedistancebetweenaspecificpointofonecompressionandrarefaction,tothesamepointofthenextcompressionandrarefaction.Thefrequencyistheamountofcompletedcyclesinasecond.Toadd,frequencyismeasuredinHertz.SosayweplayedastandardAnote,withafrequencyof440Hz.Thiswouldmeantherewas440completedcyclesofcompressionsandrarefactionsinasecond.Ifthewavelengthsareclosertogether,thepitchwouldincreaseinadditiontothefrequency.880Hz,wouldbetheoctavehigherto440Hz.Thiswouldmeanthewavelengthsareclosertogetherthantheywerebefore.Andthesameregardstoloweringthepitch.Iftherewasalowerfrequency,forexample220Hz,thenthewavelengthswouldbefurtherapartfromeachother,andthepitchwouldbeanoctavelower.Aswellaseachsoundhavingawaveformwithacorrespondingfrequency,buteachsoundhasanenvelopeinwhichyoucananalyse,andinsomecaseschange.

Eachenvelophasfourparts:ASDR(Attack,Sustain,Decay,andRelease)envelope.Thischangesthestart,core,andendofthesound,yetcanbechangedtogetnumerousdesiredeffects.Forexample,ashortattackwithashortdecay,sustainandrelease,wouldgiveyouapluck.Ontheotherhand,ifyouhadalongattackandsustain,youwouldhaveasweepeffectthatlastsforawhile,similartostrings,pads,orsweeps.Youcanalsochangethewavetableshapetoeditthesoundaswell.Youcanalsosetthesynthtobeahigherorloweroctave,byanyamountyoulike,overanyofthedifferentoscillators.AllofthesefeaturescanbefoundintheES2synthinLogicProX,forexample,however,IusedNativeInstrumentsMassiveforthisdemonstration.Inadditiontohowyouwantyourtracktosound,youhavetokeepinmindifanyofyourtracksendupphasinginthemix,whetherintentionalorbyaccident.

SometimeswhenIDJ,andbeatmatchthenextsongwiththelastsong,thekicksoccasionallycancelout.Thisisbecausetheyarethesamefrequencywiththesameamplitude,butatcompletelydifferentpositions,meaningtheyarecompletelyoutofphase.

Othertimes,thereisnoaudioeffectofthewaveforms.Thisiswherethewaveformsdon’texactlylineup.Sometimesifthekickhasbeenlayered,youcanhavesomecancellationinpartsofthekickwheredifferentfrequencieshavebeenused.Butforthemostpart,withoutofphase,youwillhavenochangeinvolume,oraslightdipinvolumewherethewaveformsdon’texactlylineup.

Youcanalsohaveascenariowherethefrequenciesarethesame,andalsohavethesameamplitude.Thisiswheretheyareinphase.Itwillresultinadoublinginvolume.

Thisisveryimportantwhenproducingormixing.Itispivotalthatthemixisascleanaspossible,andwecan’thavepartsofthemixingcancellingoutpartsofthemix,ordoublingtheminvolume,becauseitwillthroweverythingoff.InLogicProX,ifyoubouncetheMIDIregiontoanaudiofile,youwillthenhavethewaveformtoworkwith.Here,youwillbeabletocomparethatwaveformtotherestofthewaveformsofyouproject,andnotonlyhearifanythinggetsphased,butyouwillbeabletovisuallyseeaswell.Withregardstothis,youneedtokeepinmindtheHarmonics.Thiskeepstheprojectinkeyinphase.Byplayinginkey,youwillbeusingnotesthathavethesamefrequency,andifplayedatthesamevelocity,youwillhavesimilarwaveforms.Thiswillmeanthecompressionsandrarefactionswillbeinthesamearea,givingasmoothandcleanmix.Ifyouaren’tplayinginkey,youwillnumerousdifferentfrequencies,whichcouldpossiblyresultinoutofphaseorcompletelyoutofphrase,whichwon’tsoundniceasaninphaseandinkeyprojectwill.

Therearemanydifferenttypesofmusicalinstruments,suchas:strings,wind,brass,drums,andpercussion.Eachtypeofinstrumenthasdifferentcharacteristics,whichidentifieswhichgrouptheybelongin.Somecharacteristicsincludetheirfrequencyrange,structure,andcomponents.Aswecansee

eachtypeofinstrumenthasadifferentfrequencyrange.Thepianohasthewidestfrequencyrange,asitcanplaynotesaslowas28Hz,andnotesashighas3951Hz.Althoughotherstringinstrumentsdon’thaveaswidearangeasthepianodoes,itisclearthatmanyofthestringinstrumentshaveawiderfrequencyrangethanothertypesofinstruments.

Withoutvibrationsinair,wewouldhavenosound.Butforwindinstruments,itisn’taseasyashittingadrumskinorpluckingastring.Windinstrumentsgeneratetheirsoundandvibrationsinacoupleofdifferentways.Onewayisbyvibratingthereedsinthemouthpiece;andtheother,isbymovingthemusicianslipsinadifferentwaystogeneratedifferentvibrationsintheair.Eitherway,theairthencirculatesinthecylinderoftheinstrument,whichexitsandproducesthesound.Youalwaysseewindinstrumentsbeingseparatedandcleaned;asitisimperativetheystayclean.Notjustfromahygienepointofview,butiftheinstrumentisdirty,thewaveformproducedwontbeasneat,producingaharshersound.Butwithacleaninstrument,acleanwaveformwillbeproduced,andbeeasierontheear.Someexamplesofwindinstrumentsare:theflute,clarinet,oboe,piccolo,andbassoon.

Thisisthemouthpieceofawindinstrument.Here,wecanseethatthetuningwirewillbemoved,whichinturnmakesthereedmove.Thisthengivesthewaveformfortheinstrumenttoproduce.

apparentinothertypesofinstruments,forthesamereasons,tocarrythevibrationsintheairuntiltheyexittheinstrument.However,thisall

Originally,windinstrumentswouldbemadeofwood,hencetheiroldname,woodwinds.Nowadays,theyaremadeofmetal,wood,plasticoracombinationofthethree.Thesevibrationsinairwillbecarrieddownacleancylinder,asforementioned,andexit,producedtheharmonisednotesthatarebeingplayed.Lateron,wewillseethatcylindersare

happensveryfast,asthespeedofsoundis344m/swhenairisthemedium.Inothermediumshowever,itisslowerastheyaredenserthanair.Additionally,acrossallinstruments,aruleofthumbis:thebiggertheinstrumentorcylinder,thelowerthepitch;andtheshortertheinstrumentorcylinder,thehigherthepitch.Forexample,aguitarvs.aukulele.

Brassinstrumentsarestilloperatedthroughamouthpiece,butitdoesn’thaveareed.Themusicianvibratestheirlipstopushairintotheinstrument.Duetothevibrationofthelips,thewaveformsproducedarehigherfrequenciesbecausetherearemorevibrations.Duetothis,thepitchishigher.However,thislimitsthenotesthatcanbeproduced,hencetheintroductionofbuttonsandtubing.Weallknowthetrumpethasastandardhighpitch,butwhenbuttonsarepressed,moreairisletintothetube,givingmoreairtobeeffectedbythevibrations,loweringthefrequency,andinturn,loweringthepitch.Trombonesarewellknownfortheslider.Whenthesliderispulledtowardsthemouthpiece,itshortensthelengthofthetube,reducingtheamountoftheairinthetube,increasingthefrequencyandthepitch.Andwhenpushedawayfromthemouthpiece,moreairisletintothetube,whichdecreasesthefrequencyandthepitch.Anothernotedbrassinstrumentisthetuba.Thisiswellknownforitsmassivesize.Andbecauseofthesize,thereisalotofairintheinstrument,givingaverylowfrequencyandpitch.

Stringinstrumentscanbemissleadingduetotheirwoodenbody,however,thewoodenbodyhasapurpose.Thewoodishollow,whichallowsmaximumvibrationtooccuroncethestringshavebeendrawnwiththebow.Thebowhasawoodenhandle,withthehairfromhorses’tailsforthebow!Thestringsareusuallymadeofnylonorsteel,asthishasagoodtimbre.(Timbreissimplythesoundofthe

instrument).Sometimes,toachieveadifferentsound,themusiciancouldusetheirfingerstopluckthestrings,orthewoodensideofthebow.ToTheright,wecanseesomeexamplesofthewooden,stringedinstruments.Asmentionedpreviously,thesmallerinstrumentshaveahigherpitch,duetothetightervibrationsandlessair.Thismeansthatwithregardstothestrings,theviolinhasthehighestpitch,andthedoublebasshasthelowestpitch,asitisthebiggestinstrumentinthecategory.Wecanseethattheharphastwodifferentsizesoneachside.Thisgivesagoodfrequencyrange,duetothetallerlefthandside,whichwillhavealongerstringtoproducealowerfrequency,andashorterrighthandsidetoproducehigherpitchednotes.Whenusedthemusicianplayswithabow,itwillhaveadifferentenvelopeshapecomparedtowhenpluck.Imentionedpreviouslythatpluckshaveashortattack,decay,sustain,andrelease.Thisisthesameforapiano.Whenakeyispressed,ahammerstrikesthestring,givingitashortnote,unlessasustainpeddleisused.However,whenstringsareusedwithabow,theattackwillbeslower,withalongerdecay,sustain,andrelease.Thisisbecausethestringisbeingpulledtovibrateratherthanpluckingitwithfingers.Withregardstonon-orchestralstrings,thesameapplies.However,bass’aren’tusuallymuchbiggerthanguitars,althoughtheycanbebiggersometimes.Theirlowfrequencynotesareproducedwiththickerstringsandplayingstyle.Bothguitarandbasscanbepluckedwithapluck,orfingers.

Percussioninstrumentsareanyinstrumentsthatmakeasoundwhenhitorshaken.Thisimpliesthattheirenvelopewillconsistofashortattack,decay,sustain,andrelease.Achallengewhenplayingpercussioninstrumentsishittingitintime,withtherightvelocity,intherightarea,andhavingittunedinkeywiththerestofthesong.Somepercussiveinstrumentscanbetuned,othersontheotherhand,cannot.Thismeansthattheirfrequencyrangeislimited.Theirmainroleistoaddrhythmandexcitementtothesong,byhavinglayersunderthemainpiece.Percussioniststendtoplaymorethanoneinstrument;theyrarelyarerestrictedtoonetypeofpercussioninstrument,unlikemusiciansfromotherfamilies.AlthoughImentionedpianointhestringfamily,itcouldalsobeclassedasapercussioninstrumentbecauseitproducessoundsbyahammerhittingstrings.Someotherexamplesofpercussioninstrumentsaredrums,cymbals,tambourine,shakers,triangle,glockenspielandxylophone.

interpretedascompressionsandrarefactionsintheair.Onlywhenitreachestheeardrum,iswhenitisinterpretedasvibrations.Themiddleearisanair-filledcavitycontainingtheeardrum,andagroupthreesmallbonescalledtheOssicles,whichhelptoamplifythesound.ThesebonesarereferredtoastheMalleus,Incus,andStapes,orthehammer,anvil,andstirrup,asthatiswhattheylooklike.Theeardrumisadurable,permeablemembranethatvibratesinthepatternofthecompressionsandrarefactionsofthesound.Thecompressionpushesthemembraneoftheeardruminwards,whereasararefactionpullsitoutward.Thisreplicatesthefrequencyofthewaveenteringtheear.Theeardrumconnectstothehammer,anvil,andstirrup,soasthemembraneoftheeardrummoves,theOssiclesmoveinthesamepatternatthesametime.Thestirrupthenconnectstotheinnerear,whichtransmitsthepatternofthevibrationsintothefluidintheear,whichalsocarriesoutthesamewaveformrepresentation.Thestirruphasnearlyfifteentimesmorevibrationcapability,whichinturnincreasestheintensityofthevibration.Thisresultsinanincreaseinamplitude,whichmeansthevolumehasbeenamplifiedandbecomeslouder.Thisishowwecanhearthesmallestofsounds.Finally,theinnerearconsistsofthecochleaandsemi-circularcanals.Thefluidandnervecellsoftheinthesemi-circularcanalshavenoroleinhearing.Theyarepurelytohelpyoukeepyourbalance.Itmayseemstrangehavingyourbalancelocatedinyourears,buttheliquidiswhataccountsforwhetheryoufeeldizzyornot.Aswecansee,thecochleaisshapedsimilarlytoasnail.Thisalsocontainsliquid,butinadditiontothat,ithasover20,000minisculehair-likecellsthatarepivotalforyourhearing.Asthesoundwaveenterstheear,andworksitswaytothecochlea,thecompressionofthewavepushestheliquidoverthehair-likecells,andgivesthemthe“greenlight”tostartworking.Eachindividualcellhasincrediblesensitivitytofrequenciesbetween20Hzand20KHz.Onceafrequencyofasoundmatchesthefrequencyofthecell,thatcelltriggersthesamewave,howeverwithalargeramplitude.Thisintenseamplitudethentriggersanelectricalcurrentthatpassesalongtheauditorynerve,towardsthebrain.Nervesmeetthatcurrent,andtheinformationisinterpretedsoweunderstandwhatwehaveheard.Ifwedon’tcomprehendwhatwehaveheard,thebrainisabletotakethesurroundingfrequenciesandusecontextcluesastowhatwehaveheard.Impressively,thisallhappensinfractionsofasecond.

Withoutadoubt,theearisthemostimportantpartofmusic.Withouttheear,wewouldobviouslynotbeabletohearanything,orappreciatethebeautyofmusic.Asmusicians,itisimperativeweunderstandtheroleeachpartoftheearhas,andhowwecanlookafterourearssotheycanserveustofullpotentialforthelongestamountoftimepossible.Iwillbegoingintodepthforeachpartoftheear,howitinterpretssound,andhowitcanbeprotected.

Therearethreecorepartstotheear,theinnerear,middleear,andouterear.Workingfromtheoutsidein,wewillbegintodiscusstheouterear.Thiswillmostlikelybemorecommontomost,incomparisontotherestoftheear.Theouterearconsistsoftheearflaporthepinna.ThisprovidesprotectionforthemiddleeartoavoiddamagetotheTympanicMembrane,ortheeardrum.Theouterearisspecificallyshapedtocatchthesoundwaves,andchannelthemintothemiddleear.DuetothelengthoftheExternalAuditoryMeatus,ortheearcanal,itiscapableofamplifyingsoundswithfrequenciesashighas3,000Hz.Untilthesoundreachestheeardrum,itisstill

Somefactorsofhearing,however,andtodowiththebrainratherthanthephysicalearitselfandthesciencebehindit.Psychoacousticsistheperceptionofsoundwithpsychologicaleffect.Forexample,thecocktailpartyeffect;noticehowwhenyou’retalkingtosomeone,youcanonlypayattentiontoyourconversation–everyoneelse’sconversationdrownsoutandbecomesbackgroundnoise.Thisisbecauseofthecocktailpartyeffect.Yourbrainautomaticallytunesintothefrequenciesofsomethingyouarepayingattentionto.Itisthesamewhensomepeopledisappearinto“phoneland”.Theyaresoengrossedintheirphonethatpeoplewhotrytotalktothemhavetorepeatthemselvesafewtimesovertobreakthecocktailpartyeffect.AnotherexampleofpsychoacousticsistheDopplereffect.Thisistheappearanceinfrequencychangeoveraperiodoftimefromapointofview.Forexample,whenyouarestandingbyabusyroad,andacarwhizzespastyou,theirenginesoundsasifitisintwopitches.Ahigherpitch,andthensweepsdowntoalowerpitch.Buttothepeopleinthecar,theengineisatoneconstanttone.Sohowcanthisbe?Imentionedearlierthatsoundisomnidirectional.Thismeansthattheengineisemittingsoundallaroundthecar.However,thedirectionthatthecaristravellingin,thosesoundwavesgetsquashedbythecar,andbecomeclosertogether.Becausethecompressionsandrarefactionsareclosertogether,thismeansthefrequencyishigher,havingahigherpitch.Equally,the

CocktailPartyEffect

DopplerEffect

soundwavesoftheenginebehindthecararenowdraggingbehindthecar,increasingthedistancebetweeneachcycleofcompressionandrarefaction.Thismeansthefrequencyislower,whichinturnresultsinalowerpitch.AnotherexampleofpsychoacousticsistheHaas

HaasEffectEffect.Thisissimplytheabilityofourearsbeingabletolocalisethedirectionofsoundfromthereflectionsintheroom.We’veallheardaloudbanginaroombefore,andseeneveryone’sheadrapidlyturninthedirectionofthesource.Thisisbecausethesoundwavesareprojectedineverydirection.However,somesoundwavesaremoredirectthanothers.Thisishowwecantellthedirectionbecausetheinformationarrivestoourearsfaster.Notonlythis,buteveryothersoundwavewillbecomingatusfromanangleduetoitbouncingoffofsurfaces,soourbraincaninterprettheanglewereceivethewavesat,andworkoutthegeneraldirectionofthesound.Sometimes,producershavesoundsinarecordingthattheydon’twant,however,theycan’tnecessarilydeleteitallthetime.Whenthishappens,theycanmaskthesoundwithanothersound,makingtheundesiredsoundnotstickoutasmuchorexistatall.Itisimportanttorememberphase,whentalkingaboutthenexttopicofpsychoacoustics–beats.Essentially,thisiswhenyouhavenotesatasimilarfrequencyallplayingatthesametimeatthesameamplitude.Initially,theywillallbeinphaseasthefrequenciesaresoclosetoeachother.However,astimegoesonandtheloopcontinues,thedifferentwaveformsbecomeoutofphase,producingawavingwobble,andthenlateron,completelyoutofphase,untilthetwowaveshavecaughtuptowheretheywerepositionedatthebeginning.

Aswellasprotectingyourears,itisalsoimportantthatyouprotectyourworkstation.Asamusician,yourearsarethemostimportantpartofyourcareer.Inordertokeepyourearsfromlosingtheirabilitytohear,youneedtolookafterthem,byavoidinglisteningtounnecessarilyloudmusic.However,insomescenariosthatisimpossibletoavoid,sotopreventdamagetoyourears,youcanwearearplugstolessentheintensityofthesoundwavesbeingletintoyourears.Whenmixinginthestudio,itisimportantthatweachieveacleanmixwithoutclippingordistortionhappening,becausenotonlydoesthisnotsoundgood,butitisn’thealthyforyourearseither.Clippinganddistortionoccurswhenyoureachtheredzoneinthemixer,aswe

canseeinthescreenshottotheleft.Thiscouldresultinanunevenmix,andcouldpossiblymaskoverother,moresubtlepartsofthemix.Itisagoodgeneralideatoputcompressorsonyoursoftwareinstruments.Thisiswhereyoucansetthethresholdforyoursound.Thistendstolowerthevolume.Butnottoworry,asthiscanbeeditedinthecompressoraswell,becauseyoucanadjustthemakeupoutput,bringingthevolumebackuptowheretheartistwishes.Clippinganddistortionisn’thealthyforyouspeakersaswellasyourears.Thiswillcausethespeakerstoworkharderthantheyneedtobeorshouldbe.Anotherhealthandsafetyforyourspeakersisyoushouldalwayslowerthevolumeonthem,thenturnthemoff,andthendisconnectthem.Whenpeoplejustpullouttheconnectiontothespeakersbeforetakingprecautions,youhearapoppingnoise,andthiscouldblowthespeakers.Thesamegoesforconnectingtothespeakers–alwaysmakesuretheyareturnedoffwiththevolumedownbeforeconnecting.Anotherhealthandsafety,fortheconsiderationofothers,ishygiene.Thereisnothingworsethanworkinginaconfinedspacewithotherpeople,andoneofyousmell.Itsoundssilly,butthiscouldbeoffputtingforsomepeopleandblocktheir

ideas.Continuingfromthis,musicequipmentisveryexpensive,soitisimportantyoulookafteritwell.Limittheamountofpeopleinastudiotoaslittleaspossible,andavoideatinganddrinkingwhileworking.Thiswillkeeptheworkspaceinasgoodaconditionaspossible.Alsoconsideringcleaningyourequipmentatleastweeklyaswelltoensurethateverythingrunsasmoothasitpossiblycan.Obviouslymostequipmentwillrequiretheuseofelectricity,whichcancausemanyhazardsitself.Firstly,makesureyoudon’toverloadonesocket.Thiscouldresultinblowingthefuse.Makesureyouhavenumerousplugsaroundthestudiotoavoidoverload.Also,havingalotofplugswilllimitthechanceoftriphazards.Makesurethatallwiresareasneataspossible,whetherthismeanstapingthemtothefloor,orbuyingextensioncablessothebulkofthewirecanbehiddenawayneatly.Workingwithelectricitycanalsobringfirehazards.Soifyoudon’thaveafireextinguisherinthestudio,makesureyouhaveoneincloseproximity.Butitiscommonknowledgeelectricityandfiredon’tmixwell,soifpossibletrytousefoamextinguishers.

Therearemanydifferentareasinwhichmusiccanbeplayed.Locationscanrangefromarecordingstudio,toafestivaloutside,oraconcertinside.However,nomatterwherethemusicisbeingplayed,youalwayshavetokeepinmindsomekeyfeatures.Forexample,RT60,whichisessentiallytheamountoftimethereverbtakestodecreasebysixtydecibels.Iwenttothemusicvenueatcollegetoshowanexampleofhowthiscanbeworkedout.Inordertoworkthisout,Ihadtotakethemeasurementsofthe

ceiling,floor,andwalls.Thiswouldallowmetoworkoutthevolumeandsurfaceareaoftheroom.Ithenhadtotakeintoconsiderationofthetypesofmaterialeachpartoftheroomwasmadeof.Eachtypeofmaterialhasadifferentabsorptioncoefficient.Thisishowmuchofthewaveformgetsabsorbedbythematerial.0isnoabsorptionatall,whereas1isthewholesoundwavegetsabsorbed.Anotherfeatureyouhavetokeepinmindiswhethertheroomwillhavestandingwavesornot.Thisiswhenthevibrationalpatterninamediumisreflectedoverandover,causinganincreaseinvolume.Thisisbecausethewavelengthistoolongtobeabsorbed.Thiscanbeavoidedbyhavingasoundproofstudio.Thiscanbeachievedbyusingmaterialsthathaveahighabsorptioncoefficient,suchasupholstery,oracoustictile,forexample.

Consideringmybedroomwouldbetransformedtoarecodingstudio,Iwouldhavetoconsidertheshapeandmaterialsusedforthiscouldeffecttheoverallrecording.Iwoulddesignthestudiotohavematerialswithahighabsorptioncoefficient.Thisway,thewavesproducedfrominstrumentsorpeopleinthestudiowouldbeabsorbedandnotreflected,preventingstandingwaves,andanincreaseinvolume.Additionally,I’davoidfeedbackthiswayaswell.Transitioningtothehardwareandsoftware,IwouldhavebothAbletonLive9andLogicProX.WhydoIneedtwoDAW’s?Tobeginwith,I’duseaNovationLaunchkey49formyMIDIkeyboard,andthisdoesn’tmapwellwithLogicProX,however,itdoesworkwellwithAbleton.Additionally,AbletonhasmoreeditingfeaturesandliveperformancecapabilitiesratherthanLogic.However,IdopreferLogicformyoverallworking.I’dalsohaveaNativeInstrumentsMaschineMK2.Thisisanadvanceddrummachinethathasnumerousdifferentpagesandsampleoptionsforrecordingandediting.I’dalsoneedaninterfacetolinkupmycompressormicrophone,whichwillmeanIwillproducewaveformsintoLogicorAbleton.