Downloaded from orbit.dtu.dk on: Oct 09, 2021 High-intensity, focused ultrasonic fields Jensen, Leif Bjørnø Published in: Acoustical Society of America. Journal Link to article, DOI: 10.1121/1.2025494 Publication date: 1988 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Jensen, L. B. (1988). High-intensity, focused ultrasonic fields. Acoustical Society of America. Journal, 83(S1), S71-S71. https://doi.org/10.1121/1.2025494 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. PROGRAM OF The 115thMeeting of the AcousticalSociety of America SeattleSheraton Hotel andTowers ß Seattle,Washington ß 16-20 May 1988 MONDAY EVENING, 16 MAY 1988 WEST BALLROOM, 7:00 TO 9:00 P.M. Tutorial Lecture Acousticintensity technique. Jiri Tichy(Pennsylvania State University, Graduate Program in Acoustics, AppliedResearch Laboratory, University Park, PA 16802) Radiationand propagation ofsound energy represents fundamental knowledge in all subfields ofacoustics andvibration. The intensity technique was initially developed for sound power measurements butit canbe used asa generaltool for sound field investigations. This is possible by recent developments ofsignal processing and precisioninstrumentation technology which permit identification of detailed behavior of vibratingsurfaces, mappingof soundfields in termsof soundpressure, particle velocity, complex acoustic intensity and energy densities,construction ofwave fronts, and determination of phaseand group velocities. The tutorial will cover thefundamentals of all aspectsof theintensity technique. Basic theoretical relationships of sound energy generationand propagation will be discussed. The basics of the measurement technique, using two-microphone probesor pressure-velocityprobes, and the appropriate dedicated instrumentation or more general computer use,will be discussed. The tutorial will briefly handle the precision ofthe measurements. A great deal of time willbe devoted to examplesof applicationson radiation from simple and complex sources and their nearfields. Themaps of energy propagation, sound pressure and particle velocity, as well as the formation of vortices,will beshown. Specific applications in manyareas of acousticswill besummarized. Afterthe lecture, various companies will demonstratethe latest commercial equipment available to make acousticintensity measurements. TUESDAY MORNING, 17 MAY 1988 GRAND BALLROOM C, 8:15 TO 11:42 A.M. SessionA. SpeechCommunication I: Analysis, Coding, and Synthesis Peter Benson, Chairman I TTDefence Communication Division, 10060 Carroll Canyon Road, San Diego, California 92131 Chairman's Introduction--8:15 ContributedPapers 8:17 8:32 A1. An optimal classof generalizedtime-frequency representations for A2. Formant estimation from noisy voiced speech. A. nonstationarysignal analysis. Yunxin Zhao, Les E. Atlas, and Robert K. Krishnamurthy,J. Li, and R. L. Moses(Department of Electrical J. Marks, II (Department of ElectricalEngineering, FT-10, University Engineering,The Ohio StateUniversity, 205 DreeseLaboratories, 2015 of Wnahington,Seattle, WA 98195) Neil Avenue, Columbus, OH 43210) In this paper,a classof generalizedtime-frequency representations This paperconsiders the estimation for formantfrequencies and band- (GTFR) that haveboth good time and good frequency characteristics for widthsfrom voicedspeech signals that aredegraded with additivewhite nonstationarysignal analysis is presented.The basisof the approachused noise.Each period of thespeech signal is dividedinto theopen and closed isthat a time-frequencyrepresentation can, in somecases, be improved by glottalphases using the electroglottograph signal. The speech signal in the allowingnegative value of thespectrum. The representation(and its asso- closedphase is modeled as the sum of dampedsinusoids, with eachsinus- ciatedkernel) can then be optimizedto enhancethe peaksin frequency oldcorresponding to oneformant. The analysisprocedure thus leads to an whilestill maintainingfinite time support. The finitetime support proper- estimateof the frequency,bandwidth, and energyof eachformant. The ty hasthe significance of preservingonset times of signalsand also provid- resultsindicate that typicallyjust threeformants account for mostof the ing clear representationsof fast-changingspectral peaks. Experiments energyin the closedphase. The noise-robustnessproperties of the algo- wereperformed on simulateddata and real speechfor comparisonof the rithm are increasedby usinga total least-squaresapproach in obtaining GTFR with the spectrogramand the pseudo-Wignerdistribution. The the parametersand by using data from multiple consecutiveclosed resultsshow distinctadvantages of the GTFR. For example, onsetsof phases.This work verifiesand extendsthe resultsof S. Parthasarathyand transitionsare clearerand, in the caseof speech,close formant peaks are D. Tufts [IEEE Trans.Acoust. Speech Signal Process. ASSP-35, 1241- easierto distinguish.[Research supported by NSF and Boeing.] 1249(1987) ]. [Work supportedby theOSU Seedgrant program. ] $1 d. Acoust.Soc. Am. Suppl. 1, Vol. 83, Spring 1988 115th Meeting:Acoustical Society of America $1 8:47 9:17 A3. Voiced speechmodel includingsource-tract interaction. A. K. AS. A real-time frequency-shift decoder for the last transmissionof Krishnamurthyand J. Li (Departmentof ElectricalEngineering, The Korean Airlines flight 007. John D. Schlatter and Les E. Atlas Ohio State University, 205 Dreese Laboratories,2015 Nell Avenue, (Department of Electrical Engineering, FT-10, University of Columbus, OH 43210) Washington,Seattle, WA 98195) This paperconsiders the problemof estimatingthe parametersof a On 1 September1983, Korean Airlinesflight 007 wasintercepted and voicedspeech model that includesthe effectsof source-tractinteraction. destroyedby a Sovietjet fighterafter strayinginto Sovietairspace. Al- Basedon work by Ananthapadmanabhaand Fant [ SpeechCommun. 1, though the flight recorderfrom KAL 007 was not recovered,its final 167-184 (1982) ], the voicedspeech signal is modeledas the outputof a transmissionswere recordedat a Tokyo air traffic control center. The time-varyingvocal tract filter excitedby a parametrizedglottal source intelligibilityof the KAL 007 tansmissionsis compromisedby at least waveform.The glottalsource waveform [ Fant et al., STL/QPSR (1984) ] three types of distortion:broadband background noise, narrow-band modelsthe main pulse shapeof the glottal volume velocity and is de- noisetone, and frequency-shiftdistortion. This paper describesa DSP scribedby four parameters.The effectof source-tractinteraction is mod- systemthat hasbeen developed to counteractthe frequency-shiftdistor- eledby varyingthe frequency and bandwidth of thefirst formant in synch- tion. The systememploys Hilbcrt transform-basedtechniques to intro- rony with the glottal source waveform. An analysis-by-synthesis ducea linearcompensating frequency shift, the extentof whichmay be approachis usedto estimatethe parametersof the model.Algorithms for controlledmanually by theuser or automaticallyby a separatecomputer. estimatingthe parametersof the glottal sourcewaveform and the vocal Testsperformed to date with the systemon the KAL 007 transmissions tractfilter are described. Comparisons of thespectrum of theoriginal and haveshown it to bea usefultool. Intelligibility improvements have led to synthesizedspeech waveforms are presented.[Work supportedby the independentlyverified advances in understandingseveral of KAL 007's OSU Seedgrant program. ] final transmissions. 9:32 9:02 A6. Large-band integrated vowel representations.Marlos Mantakas, A4. Distribution of spectral errors with quantization of frequenciesand Jean-Luc Schwartz, and Pierre Escudier (Laboratoire de la bandwidths of LPC poles. Bishnu S. Atal (Acoustics Research Communication Par16e, I.C.P.-Unit6 associ6e au C.N.R.S., Department,AT&T Bell Laboratories,Murray Hill, NJ 07974) E.N.S.E.R.G.-I.N.P.G., 46 avenue F61ix-Viallet, 38031 Grenoble, France) In low bit ratespeech coding systems, the LPC spectralinformation is oftencoded in termsof quantizedpartial correlations or line-spectral "Gross"vowel spectrum parameters for vowelclassification are of pairs.The distributionof spectralerrors with suchquantization has been interestto manyresearchers. In thepresent study, the "effectiveformant" studiedin the past.However, not muchis knownabout the distribution of F'2, estimatedby thelarge-band spectral integration (LBI) model[ Escu- spectralerrors when the frequenciesand bandwidthsof LPC polesare diet et aL, Acts of the French-SwedishSeminar, Grenoble, France quantized.The quantizationof frequenciesand bandwidthshas impor- (1985) ], in the classificationof natural Frenchfront vowels/i/vs/y/ tant advantagesbecause the perceptual sensitivity to quantizationof these and/e/vs/•/(rounding