University of Toronto, Erindale Campus, Mississauga, Ontario L5L 1 C6,. Canada), and Sandra K. Marshall (Environmental Studies, York. University, Downsview ...
jectsagreedthat the equaltemperedversionwasmostconsonant but the orderingof the other tuningsdependedon musicaltrainingand on previousexposureto thesenontraditionalsounds.
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004. Music and meaning. Annabel J. Cohen, Sandra E. Trehub, Lena Guerriero (Centre for Research in Human Development,
Universityof Toronto,ErindaleCampus,Mississauga, OntarioL5L 1C6, Canada), and Sandra K. Marshall (Environmental Studies, York University,Downsview,OntarioM3J 1P3,Canada) Collegestudentsand preschoolchildrenrated dichotomoustone sequencesvaryingin intensityand rangeon the bipolaradjectivescaleof sadness/happiness. Both groupsassigned the modalresponse of happyto the high/fast stimulusand the modal responseof sadto the low/slow stimulus.In anotherstudy,differences in the meaningof two contrasting selections by Prokofieffwereindicatedby ratingsof collegestudentson 12 bipolar adjectivescales.The selections,when usedas soundtracksfor a short animation,led to differentbipolar adjectiveratingsof elementsin the film. In a final study, original contrastingsoundtracksdiffering in meaning,as indicatedby studentratings,alsoled to a significantdifferencein the meaningassigned to the film. Overalltheseresultsimply that musicalrelationsgive rise to meaningin systematicwaysand that such meaningmay be acquiredasearlyasthe preschoolage.Sincemusiccan influencethe interpretationofnonmusicalevents,it is suggested that musicalmeaningispresentedin a generalsemanticsystemwheredisjunctive entitiesat variouslevelsof abstractionfrom differentmodalitiesmay conjoin to form new concepts.
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005. Pressurewavereflectionsin a barredorganwindchest.T. L. Finch
{St. LawrenceUniversity,Canton,NY 13617}and A. W. Nolle {The Universityof Texasat Austin, Austin,TX 78712} The effectsof windchestdesignon the pressureriseand henceon the startingtransientof organpipe speechhavebeeninvestigated by Caddy andPollard[Acustica7, 277(1957}]andbyLottermoser [Z. Angew.Phys. 20, 424 {1966}].Their resultsweredescribed by equivalentcircuitswith
lumpedconstants. We showmeasurements of windchest pressure, pipe soundoutput, and wind velocityinto the pipe foot as functionsof time, usinga 1.5-m-longnotechannelof a barredwindchestwith a hand-operatedpalletvalve.The resultsindicatethat a longchannelmustbeconsideredasan acoustictransmission line.For a rapidopeningof thepallet,the pressure signaladvancing alongthechannelconsists of (a)a negativepulse due to the palletdisplacement, followedby (b)a risingpressurestepof heightPs, the supplypressure. Whenthe pulseis reflectedfrom the rigid far endof the channel,a pressurepedestalof heightapproaching 2ps,and duration2(length}?c is observed there.At otherpositions, theinitialpressureriseis followedby a delayedfurtherrisedueto the returningreflection. [TLF is visitingScholar,The Universityof Texasat Austin, 19841985.]
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006. Piano stringsand low-masshammers.Donald E. Hall {Physics Department,California StateUniversity,Sacramento,CA 95819} Considera stringof lengthœand massM struckat a distanceb from one end by a hammer of massm. In the limit where rn•M, the hammer reboundsfrom the stringjust after the arrival of the firstreflectedwaveat
t -- 2b/c. It regains 1/e2= 13.5%ofitsoriginalenergy. Theenvelope of thestringspectrum isgivennotbysin2 nb/L butby(1 + l/e)2sin2 nb/L(4/e)sin4 nb/L, and the strongest harmonics are thosewith sin2nb/ L --0.64 rather than 1.0. In a better approximation,the two impulses &livered to the stringare not instantaneous but havedurationsof order mL/2Mc, sothat the spectrumdropsoff rapidlyabovef= Mc/mL. The rangeof parametersb/L andm/M for whicha completesolutionmay be calculatedwith a singlereflectionwill be discussed.
S90
d. Acoust.Soc.Am. Suppl.1, Vol. 77, Spring1985
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007.
Resonant frequencies of a musical wind instrument. J.
Duane Dudley and William J. Strong (Departmentof Physicsand Astronomy,BrighamYoungUniversity,Provo,UT 84602) We considerfour possiblewaysof definingand calculatingresonant frequencies of a closed-open air columnin a musicalwindinstrument: (1) maximaof an input impedanceversusfrequencycurve,(2) maximaof a powerinputcurve,(3)frequencies at whichinputreactance vanishes (i.e., zerophaseangle,whereinputimpedance is purelyresistive), and(4)frequenciesat whicha pressureantinodeoccursat the inlet. For manybore shapes (cylinder,trombonebell,etc.)theseyieldnearlythesamefrequencies.Howeverthereare otherssuchasa simpletruncatedconefor which thesemethodsgiveresultsthat differbyseveralpercent.A furthercomplicationthat occurswith the truncatedconeis that the input reactance doesn'tvanishafterthe firstfew modes,nor doesa standingwaveoccur with a pressureantinodeat the inlet for more than the first few modes. Sinceexperimentalresonance curvesare usuallyobtainedby measuring the inlet pressureamplitudewith a constant-flow source,it is concluded that the maximuminputimpedancecriterionisprobablythemostmeaningful for our purposes.
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008.
An acoustic pulse generator for wind instrument bores. R.
Dean Ayers,LowellJ. Eliason,andM. Mongi BenSalem{Department of Physics-Astronomy,California State University, Long Beach, CA 90840) An inexpensive piezoelectrictransducerdescribedearlier[M. I. Ibisi andA. H. Benade,J. Acoust.Soc.Am. Suppl.1 72, S6311982•] is driven by an arbitraryIdigital•waveformgenerator.The width andshapeof the volumevelocitypulsegeneratedare controlledby WienerIleast-meansquares• filtering[A. C. Holly, J. Acoust.Soc.Am. 75, 973-976 11984•]. Using a Hanning pulse,or one cycleof a raisedsinusold,we haveexamined the reflectedand transmittedwavesthat ariseat simplediscontinuitiesin bores.One particularlyunusualresultis an exponentially growing wakein thepressureresponse to a volumevelocitypulsegenerafed at the closedlargeendof a cone.Thiswakeisrequiredto satisfytheconservation of massin a closedsystem,asis alsothe casefor the exponentiallydecaying wakethat arisesat the closedsmallendof a cone[R. D. Ayers,L. J. Eliason, and D. Mahgerefteh,J. Acoust. Soc. Am. Suppl. 1 74, S29 (1983).]
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009. Multiple reflectionsin simpleboreshapes.R. Dean Ayers,Lowell J. Eliason, and Anthony S. Lee (Department of Physics-Astronomy, CaliforniaStateUniversity,LongBeach,CA 90840}
The acousticpulsegeneratordescribed in the previouspaperhasbeen usedto examineextendedimpulseresponses in boresof simplegeometry with relativelyfew,distinctdiscontinuities. Thesearepressure waveforms at theinputendthatresultfromtheapplicationof a singlevolumevelocity pulsethere. The complexinput impedancecurve of a boreis just the Fourier transformof its extendedimpulseresponse, sothat curvecanbe displayedlive on an FFT spectrumanalyzer[A. H. Benade,J. Acoust. Soc.Am. Suppl.1 70, S22{1981}].Theoreticalimpulseresponses for individualreflectionsand transmissions havebeenconvolvedrepeatedlyfor comparisonwith the multiple reflectionsobservedexperimentally.This time-domainapproachis easyto graspintuitively,andit shedsa different lightontheregimesof oscillationthatarisewhena boreprovides feedback to a nonlinear driver.
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OO10. Simulating musical instruments using their impulse responses.
Daniel D. Sleator{AT&T Bell Laboratories, Murray Hill, NJ 07974} A functionof the woodenbox of a stringedmusicalinstrumentis to
109thMeeting:AcousticalSocietyof America
S90
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