Sökning: "Acoustical measurements"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden Acoustical measurements.

  1. 1. Acoustical properties of earplugs

    Detta är en avhandling från Engineering Acoustics, LTH, Lund University

    Författare :Per Hiselius; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; vibration and acoustic engineering; vacuum technology; hydraulics; Mechanical engineering; acoustic modelling; objective measurement; insertion loss; earplugs; HPE; HPD; hearing protectors; Two-Port; Four-Pole; attenuation; electro acoustics; acoustics;

    Sammanfattning : In this study an experimental setup for measurements of high impedance objects in ducts, yielding the acoustical Two-Port properties of the object, is applied to earplugs. A frequently used experimental setup for measuring objective acoustical properties of earplugs is that of artificial ears. Great effort is spent on duplicating the human ear. LÄS MER

  2. 2. Acoustical Measurements of Material Nonlinearity and Nonequilibrium Recovery

    Detta är en avhandling från Karlskrona : Blekinge Institute of Technology

    Författare :Kristian Haller; ; [2008]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear acoustics; nondestructive testing; activation density; slow dynamics; nonequilibrium recovery; resonance frequency; nonlinear wave modulation spectroscopy; harmonic generation; trapped modes; open resonator; sweep rate; constant strain sweep;

    Sammanfattning : A damaged material or a material with non perfect atomic geometry, dislocations or cracks, exhibits two types of characteristic responses to acoustic excitations. First is the fast nonlinear dynamics response that is present as long as the material is excited. As soon as the excitation stops the response disappear. LÄS MER

  3. 3. En perceptuell och akustisk studie av svenskans koronaler i ett dialektperspektiv

    Detta är en avhandling från Karlskrona : Blekinge Institute of Technology

    Författare :Peder Livijn; Anders Eriksson; Olle Engstrand; Frank Kügler; []
    Nyckelord :HUMANIORA; HUMANITIES; Swedish; Dialect; Typology; Perceptual discrimination; Acoustical measurements; HUMANITIES and RELIGION Languages and linguistics Linguistic subjects Phonetics; HUMANIORA och RELIGIONSVETENSKAP Språkvetenskap Lingvistikämnen Fonetik; Phonetics; fonetik;

    Sammanfattning : The purpose of this dissertation is to contribute to a typology of the Swedish language as it was spoken in the entire Swedish speaking area around the year 2000. Specifically, the plan is to base this typology solely on different pronunciations of the four coronal consonants /t, d, n/ and /l/. LÄS MER

  4. 4. Acoustical Characteristics of Aircraft Panels

    Detta är en avhandling från Stockholm : KTH

    Författare :Bilong Liu; Leping Feng; Jie Pan; [2006]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; sound transmission loss; stiffener; stiffening; aircraft panel; cylindrical shell; turbulent boundary layer; TBL; noise; sound radiation; TECHNOLOGY Engineering physics Acoustics; TEKNIKVETENSKAP Teknisk fysik Akustik;

    Sammanfattning : A deterministic approach based on a modal expansion and modal receptance method has been developed to evaluate the airborne sound insulation of aircraft panels with stringer and ring frame attachments. Furthermore, this method was extended to predict the noise radiation of stiffening panel subjected to TBL excitation. LÄS MER

  5. 5. Effective vibro-acoustical modelling of rubber isolators

    Detta är en avhandling från Stockholm : KTH

    Författare :Michael Coja; Leif Kari; Wolfgang Kropp; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Applied mechanics; Rubber isolator; Bush mounting; Dynamic stiffness; Waveguide; Fractional derivatives; Mode-matching; Pre-compressed; Prestrain; Preload; Predeformation; Viscoelasticity; Dispersion; Teknisk mekanik; TECHNOLOGY Engineering mechanics; TEKNIKVETENSKAP Teknisk mekanik;

    Sammanfattning : This thesis, gathering four papers, concerns the enhancement in understanding and modelling of the audible dynamic stiffness of vibration rubber isolators including experimental measurements.Paper A studies the performances of three different types of vibration isolator using an indirect measurement technique to estimate the blocked dynamic transfer stiffness of each specimen. LÄS MER