Introduction to Psychoacoustics and Psychoacoustic Tests Assoc

Total Page:16

File Type:pdf, Size:1020Kb

Introduction to Psychoacoustics and Psychoacoustic Tests Assoc DENORMS TRAINING SCHOOL 3 “Experimental techniques for acoustic porous materials and metamaterials” 4 – 6 December 2017, Le Mans Introduction to psychoacoustics and psychoacoustic tests Assoc. Prof. Kristian Jambrošić, PhD [email protected] University of Zagreb, Croatia Faculty of Electrical Engineering and Computing Motivation Physics is just something we measure. Reality is what we perceive. Jens Blauert 2 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Contents . Overview of the hearing process . Sound reproduction systems . Acoustic comfort . Psychoacoustics and psychoacoustic parameters . Listening tests . Examples (case studies) 3 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests . Overview of the hearing process . Sound reproduction systems . Acoustic comfort . Psychoacoustics and psychoacoustic parameters . Listening tests . Examples (case studies) 4 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Anatomy of the ear . Our sense of hearing = ear + auditory center in the brain . Parts of the ear: . outer ear . middle ear . inner ear hearing process 5 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Hearing process . Basics of the hearing process: . Sound waves enter the ear through the pinna and the ear canal which causes the eardrum to move. The eardrum vibrates with sound, very similar to a membrane of a microphone. Sound vibrations move through the ossicles to the cochlea like a system of leavers. Sound vibrations cause the fluid in the cochlea to move forth and back (movements equalized by the round window). Fluid movement causes the hair cells to bend. Hair cells create neural signals which are picked up by the auditory nerve. Hair cells at one end of the cochlea send low pitch sound information and hair cells at the other end send high pitch sound information. The auditory nerve sends signals to the brain where they are interpreted as sounds. 6 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Middle ear . Middle ear is responsible for sound conduction, but also for the acoustic reflex (protective mechanism) 7 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Inner ear 8 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Organ of Corti 9 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Frequency selectivity of the Cochlea © Fastl, Zwicker: “Psychoacoustics” 10 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Neural response of the auditory nerve . The amplitude (intensity) of the perceived sound wave is coded in auditory nerve firing impulses . Higher amplitude is coded with higher firing rate! 11 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests © Gelfand: “Hearing” Hearing threshold . Average hearing threshold of human 12 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Hearing threshold . What is the lowest sound pressure we COULD hear? . Brown noise – movement of the air molecules , constant noise at about -20 to -30 dB at mid freuqencies! 13 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Hearing threshold . Hearing threshold for other marine and land mammals: 14 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Hearing threshold . Highest audible frequency versus interaural distance: © http://acousticstoday.org/wp-content/uploads/2016/01/The- 15 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Evolution-of-Mammalian-Sound-Localization.pdf Hearing threshold . Hearing vs. vision for some mammals © http://acousticstoday.org/wp-content/uploads/2016/01/The- 16 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Evolution-of-Mammalian-Sound-Localization.pdf Auditory masking . The masking effect by a masking tone and the new masking threshold: 17 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Auditory masking . New hearing threshold because of masking tone: . Temporal masking: © Fastl, Zwicker: “Psychoacoustics” © Fastl, Zwicker: “Psychoacoustics” 18 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Binaural hearing (using 2 ears) enables directional hearing – localization of sound sources in a 3D space with a certain precision © Blauert: “Communication Acoustics” 19 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Sound localization requires some mechanisms: . interaural time difference (ITD) – mechanism that functions up to 2000 Hz . interaural level difference (ILD) – mechanism that functions from 500 Hz . dynamic localization by head movement – improves the precision of sound source localization . head related transfer functions (HRTF) – mechanism that enables sound localization in the median plane . auditory scene analysis – includes higher brain functions for sound source recognition and analysis 20 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Interaural time and level difference overview 21 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . ITD can go up to 0,6 ms for the average person . ILD depend on the difference level (because of the JND – Just Noticeable Difference) © Psychology course; http://www.appstate.edu/~steelekm/classes/psy3203/topics_F05.htm 22 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Localization precision as function of sound source azimuth and its frequency 23 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Cone of confusion – places with same ITD and ILD . Solution – dynamic localization by head movement (functions for signals longer then 1 s) © http://gyronymo.free.fr/audio3D/the_experimenter_corner.html 24 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Since the head is not round, and the torso also reflects sound . The sound signal recorded at the left and right ear will be significantly different even on the cone of confusion (HRTF!) . This effect is highly frequency dependent 25 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests © http://gyronymo.free.fr/audio3D/the_experimenter_corner.html Binaural hearing . HRTF – the reason why we are able to localize sounds in the median plane 26 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Measurements of individual HRTF’s 27 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . HRTF differences for 2 persons, same direction 28 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . HRTF difference for same person (3 measurements), different directions . Localization is better for broadband sound . This is especially true above 6 kHz where HRTF’s have greatest differences 29 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . HRTF’s and learned (from own listening experience) . If a narrowband noise signal is played anywhere from the medial plane, the sound direction seems to change with the change of the source frequency . Several seconds of learning process 30 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Auditory scene analysis 31 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . auditory scene analysis 32 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Auditory system computer models - signal driven process (bottom-up) © J. Blauert, Communication Acoustics 33 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Binaural hearing . Experiment for 2 simultaneous speech source in a real room 34 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Hearing and space © http://gyronymo.free.fr/audio3D/the_experimenter_corner.html 35 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Precedence effect . Primary effect for understanding the creation of phantom sources; the other is amplitude panning sine signal L 50ms L 5ms L 1ms C R 1ms R 5ms R 50ms 36 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Amplitude panning . The phantom image is moved by different intensities emitted by 2 or more coherent sound sources sin g g i 1 2 sin0 g1 g2 37 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Amplitude panning . Why the perceived source is called “phantom source”? 38 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Trade-off (Haas effect) . Interaction between interaural time & intensity differences 39 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Spaciousness . The influence of only one direct + one reflected sound wave 40 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Franssen effect . But… 41 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests . Overview of the hearing process . Sound reproduction systems . Acoustic comfort . Psychoacoustics and psychoacoustic parameters . Listening tests . Examples (case studies) 42 DENORMS TRAINING SCHOOL - Psychoacoustics and psychoacoustic tests Principles of psychoacoustics . Psychoacoustics - science of sound perception . It investigates statistical relationships between acoustic stimuli and hearing sensations . Psychoacoustic models mimic the hearing mechanism . A good understanding of the sensory response of the human auditory system (HAS)
Recommended publications
  • Acoustical Engineering
    National Aeronautics and Space Administration Engineering is Out of This World! Acoustical Engineering NASA is developing a new rocket called the Space Launch System, or SLS. The SLS will be able to carry astronauts and materials, known as payloads. Acoustical engineers are helping to build the SLS. Sound is a vibration. A vibration is a rapid motion of an object back and forth. Hold a piece of paper up right in front of your lips. Talk or sing into the paper. What do you feel? What do you think is causing the vibration? If too much noise, or acoustical loading, is ! caused by air passing over the SLS rocket, the vehicle could be damaged by the vibration! NAME: (Continued from front) Typical Sound Levels in Decibels (dB) Experiment with the paper. 130 — Jet takeoff Does talking louder or softer change the vibration? 120 — Pain threshold 110 — Car horn 100 — Motorcycle Is the vibration affected by the pitch of your voice? (Hint: Pitch is how deep or 90 — Power lawn mower ! high the sound is.) 80 — Vacuum cleaner 70 — Street traffic —Working area on ISS (65 db) Change the angle of the paper. What 60 — Normal conversation happens? 50 — Rain 40 — Library noise Why do you think NASA hires acoustical 30 — Purring cat engineers? (Hint: Think about how loud 20 — Rustling leaves rockets are!) 10 — Breathing 0 — Hearing Threshold How do you think the noise on an airplane compares to the noise on a rocket? Hearing protection is recommended at ! 85 decibels. NASA is currently researching ways to reduce the noise made by airplanes.
    [Show full text]
  • NOISE-CON 2004 the Impact of A-Weighting Sound Pressure Level
    Baltimore, Maryland NOISE-CON 2004 2004 July 12-14 The Impact of A-weighting Sound Pressure Level Measurements during the Evaluation of Noise Exposure Richard L. St. Pierre, Jr. RSP Acoustics Westminster, CO 80021 Daniel J. Maguire Cooper Standard Automotive Auburn, IN 46701 ABSTRACT Over the past 50 years, the A-weighted sound pressure level (dBA) has become the predominant measurement used in noise analysis. This is in spite of the fact that many studies have shown that the use of the A-weighting curve underestimates the role low frequency noise plays in loudness, annoyance, and speech intelligibility. The intentional de-emphasizing of low frequency noise content by A-weighting in studies can also lead to a misjudgment of the exposure risk of some physical and psychological effects that have been associated with low frequency noise. As a result of this reliance on dBA measurements, there is a lack of importance placed on minimizing low frequency noise. A review of the history of weighting curves as well as research into the problems associated with dBA measurements will be presented. Also, research relating to the effects of low frequency noise, including increased fatigue, reduced memory efficiency and increased risk of high blood pressure and heart ailments, will be analyzed. The result will show a need to develop and utilize other measures of sound that more accurately represent the potential risk to humans. 1. INTRODUCTION Since the 1930’s, there have been large advances in the ability to measure sound and understand its effects on humans. Despite this, a vast majority of acoustical measurements done today still use the methods originally developed 70 years ago.
    [Show full text]
  • Standing Waves and Sound
    Standing Waves and Sound Waves are vibrations (jiggles) that move through a material Frequency: how often a piece of material in the wave moves back and forth. Waves can be longitudinal (back-and- forth motion) or transverse (up-and- down motion). When a wave is caught in between walls, it will bounce back and forth to create a standing wave, but only if its frequency is just right! Sound is a longitudinal wave that moves through air and other materials. In a sound wave the molecules jiggle back and forth, getting closer together and further apart. Work with a partner! Take turns being the “wall” (hold end steady) and the slinky mover. Making Waves with a Slinky 1. Each of you should hold one end of the slinky. Stand far enough apart that the slinky is stretched. 2. Try making a transverse wave pulse by having one partner move a slinky end up and down while the other holds their end fixed. What happens to the wave pulse when it reaches the fixed end of the slinky? Does it return upside down or the same way up? Try moving the end up and down faster: Does the wave pulse get narrower or wider? Does the wave pulse reach the other partner noticeably faster? 3. Without moving further apart, pull the slinky tighter, so it is more stretched (scrunch up some of the slinky in your hand). Make a transverse wave pulse again. Does the wave pulse reach the end faster or slower if the slinky is more stretched? 4. Try making a longitudinal wave pulse by folding some of the slinky into your hand and then letting go.
    [Show full text]
  • Nuclear Acoustic Resonance Investigations of the Longitudinal and Transverse Electron-Lattice Interaction in Transition Metals and Alloys V
    NUCLEAR ACOUSTIC RESONANCE INVESTIGATIONS OF THE LONGITUDINAL AND TRANSVERSE ELECTRON-LATTICE INTERACTION IN TRANSITION METALS AND ALLOYS V. Müller, G. Schanz, E.-J. Unterhorst, D. Maurer To cite this version: V. Müller, G. Schanz, E.-J. Unterhorst, D. Maurer. NUCLEAR ACOUSTIC RESONANCE INVES- TIGATIONS OF THE LONGITUDINAL AND TRANSVERSE ELECTRON-LATTICE INTERAC- TION IN TRANSITION METALS AND ALLOYS. Journal de Physique Colloques, 1981, 42 (C6), pp.C6-389-C6-391. 10.1051/jphyscol:19816113. jpa-00221175 HAL Id: jpa-00221175 https://hal.archives-ouvertes.fr/jpa-00221175 Submitted on 1 Jan 1981 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. JOURNAL DE PHYSIQUE CoZZoque C6, suppZe'ment au no 22, Tome 42, de'cembre 1981 page C6-389 NUCLEAR ACOUSTIC RESONANCE INVESTIGATIONS OF THE LONGITUDINAL AND TRANSVERSE ELECTRON-LATTICE INTERACTION IN TRANSITION METALS AND ALLOYS V. Miiller, G. Schanz, E.-J. Unterhorst and D. Maurer &eie Universit8G Berlin, Fachbereich Physik, Kiinigin-Luise-Str.28-30, 0-1000 Berlin 33, Gemany Abstract.- In metals the conduction electrons contribute significantly to the acoustic-wave-induced electric-field-gradient-tensor (DEFG) at the nuclear positions. Since nuclear electric quadrupole coupling to the DEFG is sensi- tive to acoustic shear modes only, nuclear acoustic resonance (NAR) is a par- ticularly useful tool in studying the coup1 ing of electrons to shear modes without being affected by volume dilatations.
    [Show full text]
  • Sprachrohr Heft 58
    Sprachrohr Heft 58 ‐ Juni 2012 Vorschau AIA‐DAGA 2013 3 DEGA aktuell 6. DEGA‐Symposium 11 Mitgliederversammlung 11 Tag gegen Lärm 19 Ehrungen Helmholtz‐Medaille 24 Lothar‐Cremer‐Preis 28 DEGA‐Studienpreis 30 Helmholtz‐Medaille für Weitere Ehrungen 31 Prof. Wolfgang Fasold Fachausschüsse / Fachgruppen Lothar‐Cremer‐Preis für Arbeitsring Lärm der DEGA 34 Dr. Franz Zotter Bau‐ und Raumakustik 35 Elektroakustik 35 Fahrzeugakustik 37 Hörakustik 39 Lärm: Wirkungen und Schutz 42 Musikalische Akustik 42 Physikalische Akustik 44 Strömungsakustik 44 Ultraschall 45 DEGA‐Akademie 47 Aktuelles in Kürze 49 Publikationen 54 Geschichte der Akustik: Mitglieder / Fördermitglieder 57 Impressum / Kontakte 61 Heft 4 erschienen herausgegeben von der Deutschen Gesellschaft für Akustik e.V. AIA‐DAGA 2013 Vorschau AIA‐DAGA 2013 Die AIA‐DAGA 2013 ist Teil der Kon‐ ferenzreihe „Euroregio” der European Acoustics Association (EAA) und umfasst die 39. Deutsche und .die 40 Italienische Jahrestagung für Akustik und wird unterstützt von der Österrei‐ chischen (AAA) und der Schweize‐ rischen Gesellschaft für Akustik (SGA‐ SSA) sowie der Landesagentur für Umwelt / Autonome Provinz Bozen Südtirol. Nach vier Tagungen in Österreich 1990, in der Schweiz 1998, in Frank‐ reich 2004 und in den Niederlanden AIA‐DAGA 2013 2009 setzt die DEGA damit die erfolg‐ reiche Reihe von Gemeinschaftstagun‐ Gemeinschaftstagung für Akustik gen mit benachbarten akustischen EAA Euroregio, 18.‐21. März 2013 Gesellschaften fort. Auch bei der AIA‐ DAGA 2013 werden die Organisatoren einschließlich: mit allen Kräften für eine attraktive • 40. Italienische Jahrestagung für und ereignisreiche Tagung sorgen. Akustik (AIA) So werden u. a. in sechs Plenarvorträ‐ • 39. Deutsche Jahrestagung für gen aktuelle Trends und künftige Ent‐ Akustik (DAGA) wicklungen zu zentralen Fragen der Akustik aufgezeigt.
    [Show full text]
  • Acoustics & Ultrasonics
    Dr.R.Vasuki Associate professor & Head Department of Physics Thiagarajar College of Engineering Madurai-625015 Science of sound that deals with origin, propagation and auditory sensation of sound. Sound production Propagation by human beings/machines Reception Classification of Sound waves Infrasonic audible ultrasonic Inaudible Inaudible < 20 Hz 20 Hz to 20,000 Hz ˃20,000 Hz Music – The sound which produces rhythmic sensation on the ears Noise-The sound which produces jarring & unpleasant effect To differentiate sound & noise Regularity of vibration Degree of damping Ability of ear to recognize the components Sound is a form of energy Sound is produced by the vibration of the body Sound requires a material medium for its propagation. When sound is conveyed from one medium to another medium there is no bodily motion of the medium Sound can be transmitted through solids, liquids and gases. Velocity of sound is higher in solids and lower in gases. Sound travels with velocity less than the velocity 8 of light. c= 3x 10 V0 =330 m/s at 0° degree Lightning comes first than thunder VT= V0+0.6 T Sound may be reflected, refracted or scattered. It undergoes diffraction and interference. Pitch or frequency Quality or timbre Intensity or Loudness Pitch is defined as the no of vibrations/sec. Frequency is a physical quantity but pitch is a physiological quantity. Mosquito- high pitch Lion- low pitch Quality or timbre is the one which helps to distinguish between the musical notes emitted by the different instruments or voices even though they have the same pitch. Intensity or loudness It is the average rate of flow of acoustic energy (Q) per unit area(A) situated normally to the direction of propagation of sound waves.
    [Show full text]
  • Psychoacoustics Perception of Normal and Impaired Hearing with Audiology Applications Editor-In-Chief for Audiology Brad A
    PSYCHOACOUSTICS Perception of Normal and Impaired Hearing with Audiology Applications Editor-in-Chief for Audiology Brad A. Stach, PhD PSYCHOACOUSTICS Perception of Normal and Impaired Hearing with Audiology Applications Jennifer J. Lentz, PhD 5521 Ruffin Road San Diego, CA 92123 e-mail: [email protected] Website: http://www.pluralpublishing.com Copyright © 2020 by Plural Publishing, Inc. Typeset in 11/13 Adobe Garamond by Flanagan’s Publishing Services, Inc. Printed in the United States of America by McNaughton & Gunn, Inc. All rights, including that of translation, reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise, including photocopying, recording, taping, Web distribution, or information storage and retrieval systems without the prior written consent of the publisher. For permission to use material from this text, contact us by Telephone: (866) 758-7251 Fax: (888) 758-7255 e-mail: [email protected] Every attempt has been made to contact the copyright holders for material originally printed in another source. If any have been inadvertently overlooked, the publishers will gladly make the necessary arrangements at the first opportunity. Library of Congress Cataloging-in-Publication Data Names: Lentz, Jennifer J., author. Title: Psychoacoustics : perception of normal and impaired hearing with audiology applications / Jennifer J. Lentz. Description: San Diego, CA : Plural Publishing,
    [Show full text]
  • Investigation of the Time Dependent Nature of Infrasound Measured Near a Wind Farm Branko ZAJAMŠEK1; Kristy HANSEN1; Colin HANSEN1
    Investigation of the time dependent nature of infrasound measured near a wind farm Branko ZAJAMŠEK1; Kristy HANSEN1; Colin HANSEN1 1 University of Adelaide, Australia ABSTRACT It is well-known that wind farm noise is dominated by low-frequency energy at large distances from the wind farm, where the high frequency noise has been more attenuated than low-frequency noise. It has also been found that wind farm noise is highly variable with time due to the influence of atmospheric factors such as atmospheric turbulence, wake turbulence from upstream turbines and wind shear, as well as effects that can be attributed to blade rotation. Nevertheless, many standards that are used to determine wind farm compliance are based on overall A-weighted levels which have been averaged over a period of time. Therefore the aim of the work described in this paper is to investigate the time dependent nature of unweighted wind farm noise and its perceptibility, with a focus on infrasound. Measurements were carried out during shutdown and operational conditions and results show that wind farm infrasound could be detectable by the human ear although not perceived as sound. Keywords: wind farm noise, on and off wind farm, infrasound, OHC threshold, crest factor I-INCE Classification of Subjects Number(s): 14.5.4 1. INTRODUCTION Wind turbine noise is influenced by atmospheric effects, which cause significant variations in the sound pressure level magnitude over time. In particular, factors causing amplitude variations include wind shear (1), directivity (2) and variations in the wind speed and direction. Wind shear, wind speed variations and yaw error (deviation of the turbine blade angle from optimum with respect to wind direction) cause changes in the blade loading and in the worst case, can lead to dynamic stall (3).
    [Show full text]
  • A Layer Model of Sound Quality
    3rd International Workshop on Perceptual Quality of Systems (PQS 2010) 6-8 September 2010, Bautzen, Germany A Layer Model of Sound Quality Jens Blauert 1, Ute Jekosch 2 1 Institute of Communication Acoustics, Ruhr-University Bochum, Germany 2 Chair for Communication Acoustics, Technical University Dresden, Germany [email protected] Abstract There is indeed a wide agreement that − in congruence with Sound-quality is a complex and multi-layered phenomenon the classical trialism of soul, body and mind − there are three [1]. When analysing or modelling the formation process of basic kinds of percepts that our perceptual world is essentially sound-quality judgements, a variety of quality elements and composed of. Following [7], they may be denoted feelings, quality features [2] have to be taken into account, whereby the things and concepts. actual relevance and salience of each of them is situation dependent. In this paper, we present some ideas with the aim • Feelings (e.g., hunger, fear, pain, sadness, joy) are of structuring the quality-formation process into different lay- linked to processes inside the human body (incl. ers according to the degree of abstraction involved. Depending subcutane ones) and they usually are also perceptu- ally localized just there. on this degree, different sets of references and evaluation and assessment methods have to be employed. • Things (sensations) are percepts which are related to Index Terms: sound-quality assessment, abstraction level the sensory organs. In audition we usually call them auditory
    [Show full text]
  • Ebm-Papst Mulfingen Gmbh & Co. KG Postfach 1161 D-74671 Mulfingen
    ebm-papst Mulfingen GmbH & Co. KG Postfach 1161 D-74671 Mulfingen Internet: www.ebmpapst.com E-mail: [email protected] Editorial contact: Katrin Lindner, e-mail: [email protected] Phone: +49 7938 81-7006, Fax: +49 7938 81-665 Focus on psychoacoustics How is a fan supposed to sound? Our sense of hearing works constantly and without respite, so our ears receive noises 24 hours a day. About 15,000 hair cells in the inner ear catch the waves from every sound, convert them to signals and relay the signals to the brain, where they are processed. This is the realm of psychoacoustics, a branch of psychophysics. It is concerned with describing personal sound perception in relation to measurable noise levels, i.e. it aims to define why we perceive noises as pleasant or unpleasant. Responsible manufacturers take the results of relevant research into account when developing fans. When we feel negatively affected by a sound, for example when it disturbs us, we call it noise pollution. Whether this is the case depends on many factors (Fig. 1). Among other things, our current situation plays a role, as do the volume and kind of sound. The same is true of fans, which need to fulfill different requirements depending on where they are used. For example, if they are used on a heat exchanger in a cold storage facility where people spend little time, low volume or pleasant sound is not an issue. But ventilation and air conditioning units in living and working areas have to meet much different expectations.
    [Show full text]
  • Decibels, Phons, and Sones
    Decibels, Phons, and Sones The rate at which sound energy reaches a Table 1: deciBel Ratings of Several Sounds given cross-sectional area is known as the Sound Source Intensity deciBel sound intensity. There is an abnormally Weakest Sound Heard 1 x 10-12 W/m2 0.0 large range of intensities over which Rustling Leaves 1 x 10-11 W/m2 10.0 humans can hear. Given the large range, it Quiet Library 1 x 10-9 W/m2 30.0 is common to express the sound intensity Average Home 1 x 10-7 W/m2 50.0 using a logarithmic scale known as the Normal Conversation 1 x 10-6 W/m2 60.0 decibel scale. By measuring the intensity -4 2 level of a given sound with a meter, the Phone Dial Tone 1 x 10 W/m 80.0 -3 2 deciBel rating can be determined. Truck Traffic 1 x 10 W/m 90.0 Intensity values and decibel ratings for Chainsaw, 1 m away 1 x 10-1 W/m2 110.0 several sound sources listed in Table 1. The decibel scale and the intensity values it is based on is an objective measure of a sound. While intensities and deciBels (dB) are measurable, the loudness of a sound is subjective. Sound loudness varies from person to person. Furthermore, sounds with equal intensities but different frequencies are perceived by the same person to have unequal loudness. For instance, a 60 dB sound with a frequency of 1000 Hz sounds louder than a 60 dB sound with a frequency of 500 Hz.
    [Show full text]
  • Web-Based Psychoacoustics: Hearing Screening, Infrastructure, And
    bioRxiv preprint doi: https://doi.org/10.1101/2021.05.10.443520; this version posted May 11, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Web-based Psychoacoustics: Hearing Screening, Infrastructure, and Validation Brittany A. Moka, Vibha Viswanathanb, Agudemu Borjiginb, Ravinderjit Singhb, Homeira Kafib, and ∗Hari M. Bharadwaja,b aDepartment of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, IN, United States bWeldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States Abstract Anonymous web-based experiments are increasingly and successfully used in many domains of behavioral research. However, online studies of auditory perception, especially of psychoacoustic phe- nomena pertaining to low-level sensory processing, are challenging because of limited available control of the acoustics, and the unknown hearing status of participants. Here, we outline our approach to mitigate these challenges and validate our procedures by comparing web-based measurements to lab- based data on a range of classic psychoacoustic tasks. Individual tasks were created using jsPsych, an open-source javascript front-end library. Dynamic sequences of psychoacoustic tasks were imple- mented using Django, an open-source library for web applications, and combined with consent pages, questionnaires, and debriefing pages. Subjects were recruited via Prolific, a web-based human-subject marketplace. Guided by a meta-analysis of normative data, we developed and validated a screening pro- cedure to select participants for (putative) normal-hearing status; this procedure combined thresholding of scores in a suprathreshold cocktail-party task with filtering based on survey responses.
    [Show full text]