Speech Science V Akustische Grundlagen WS 2007/8.

Slides:



Advertisements
Similar presentations
Introduction to Alternating Current and Voltage
Advertisements

Physics 1025F Vibrations & Waves
Energy of the Simple Harmonic Oscillator
Simple Harmonic Motion
Physics 1251 The Science and Technology of Musical Sound Unit 1 Session 8 Harmonic Series Unit 1 Session 8 Harmonic Series.
Properties of Sound Neil Freebern. Sound Sound is produced when something vibrates. Vibrations disturb the air, creating variations in air pressure. Variation.
ISAT 241 ANALYTICAL METHODS III Fall 2004 D. J. Lawrence
Physics of Sounds Overview Properties of vibrating systems Free and forced vibrations Resonance and frequency response Sound waves in air Frequency, wavelength,
Sound waves and Perception of sound Lecture 8 Pre-reading : §16.3.
Ch. 17 – Mechanical Waves & Sound
ACOUSTICAL THEORY OF SPEECH PRODUCTION
Speech Science Speech production II – Phonation Version WS 2007/8.
SPPA 6010 Advanced Speech Science 1 The Source-Filter Theory: The Sound Source.
Speech Science Speech production I – Breathing. Topics Energy for speech The physical structures Controlling breathing in speech Homework: a) Kent, Chap.
Chapter Eleven Wave Motion. Light can be considered wavelike by experimental analogies to the behavior of water waves. Experiments with fundamental particles,
Oscillations about Equilibrium
Phy 202: General Physics II Ch 16: Waves & Sound Lecture Notes.
Chapter 13 VibrationsandWaves. Hooke’s Law F s = - k x F s = - k x F s is the spring force F s is the spring force k is the spring constant k is the spring.
Harmonics and Overtones Waveforms / Wave Interaction Phase Concepts / Comb Filtering Beat Frequencies / Noise AUD202 Audio and Acoustics Theory.
Chapter 3: Sound Wave Intensity of Periodic Sound Waves
Basic Concepts: Physics 1/25/00. Sound Sound= physical energy transmitted through the air Acoustics: Study of the physics of sound Psychoacoustics: Psychological.
Foundations of Physics
When an object moves back and forth, it is called a vibration
CHAPTER 8 TOPICS Parts of the Atom Rutherford vs. Bohr Periodic Table Metals/ Metalloids/Non-Metals Isotopes Ions and Charges Forming Compounds.
Waves and Sound Ch
Waves - I Chapter 16 Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
MUSIC 318 MINI-COURSE ON SPEECH AND SINGING
Chapter 11 Waves. MFMcGrawCh-11b-Waves - Revised Chapter 11 Topics Energy Transport by Waves Longitudinal and Transverse Waves Transverse Waves.
Wireless and Mobile Computing Transmission Fundamentals Lecture 2.
Harmonics November 1, 2010 What’s next? We’re halfway through grading the mid-terms. For the next two weeks: more acoustics It’s going to get worse before.
Experimental Phonetics Session 1- Sound Waves Golnaz Modarresi Ghavami.
1© Manhattan Press (H.K.) Ltd. Pulse Continuous waves Continuous waves 8.1 Characteristics of waves Wave motion Wave motion Graphical representation of.
Speech Science Oct 7, 2009.
Copyright © 2010 Pearson Education, Inc. Lecture Outline Chapter 14 Physics, 4 th Edition James S. Walker.
Chapter 17 Sound Waves: part two HW 2 (problems): 17.22, 17.35, 17.48, 17.58, 17.64, 34.4, 34.7, Due Friday, Sept. 11.
David Meredith Aalborg University
Chapter 11 Vibrations and Waves. Units of Chapter 11 Simple Harmonic Motion Energy in the Simple Harmonic Oscillator The Period and Sinusoidal Nature.
Structure of Spoken Language
Copyright © 2009 Pearson Education, Inc. Lecture 1 – Waves & Sound b) Wave Motion & Properties.
Speech Science VI Resonances WS Resonances Reading: Borden, Harris & Raphael, p Kentp Pompino-Marschallp Reetzp
Voice Quality + Korean Stops October 16, 2014 Don’t Forget! The mid-term is on Tuesday! So I have a review sheet for you. For the mid-term, we will just.
Vowel Acoustics March 10, 2014 Some Announcements Today and Wednesday: more resonance + the acoustics of vowels On Friday: identifying vowels from spectrograms.
Physics 1251 The Science and Technology of Musical Sound Unit 1 Session 7 Good Vibrations Unit 1 Session 7 Good Vibrations.
Hearing: Physiology and Psychoacoustics 9. The Function of Hearing The basics Nature of sound Anatomy and physiology of the auditory system How we perceive.
Chapter 15 Oscillations. Periodic motion Periodic (harmonic) motion – self-repeating motion Oscillation – periodic motion in certain direction Period.
Chapter 16 Lecture One: Wave-I HW1 (problems): 16.12, 16.24, 16.27, 16.33, 16.52, 16.59, 17.6, Due.
Chapter 13 VibrationsandWaves. Chapter 13 Objectives Hooke’s Law Hooke’s Law Simple Harmonic Motion Simple Harmonic Motion Elastic Potential Energy Elastic.
Waves - I Chapter 16 Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
CHAPTER 4 COMPLEX STIMULI. Types of Sounds So far we’ve talked a lot about sine waves =periodic =energy at one frequency But, not all sounds are like.
Chapter 16 Waves-I Types of Waves 1.Mechanical waves. These waves have two central features: They are governed by Newton’s laws, and they can exist.
صدا و ارتعاش در صنعت جلسه دوم محمد رضا منظم
Voicing + Basic Acoustics October 14, 2015 Agenda Production Exercise #2 is due on Friday! No transcription exercise this Friday! Today, we’ll begin.
Chapter 11 Vibrations and Waves.
Simple Harmonic Motion Pg Restoring Force & Periodic Motion  When a spring is extended or compressed, the restoring force either pulls or.
The Speech Chain (Denes & Pinson, 1993)
P105 Lecture #27 visuals 20 March 2013.
Chapter 15: Wave Motion 15-2 Types of Waves: Transverse and Longitudinal 15-3 Energy Transported by Waves 15-4 Mathematical Representation of a Traveling.
Basic Acoustics. Sound – your ears’ response to vibrations in the air. Sound waves are three dimensional traveling in all directions. Think of dropping.
VibrationsandWaves. Ch. 14 examines wave motion and the oscillating, vibrating motion that creates them. This oscillating motion is known as periodic.
1 Waves and Vibrations. 2 Waves are everywhere in nature Sound waves, visible light waves, radio waves, microwaves, water waves, sine waves, telephone.
Wave Motion Types of mechanical waves  Mechanical waves are disturbances that travel through some material or substance called medium for the waves. travel.
HOW WE TRANSMIT SOUNDS? Media and communication 김경은 김다솜 고우.
Physics 1 What is a wave? A wave is: an energy-transferring disturbance moves through a material medium or a vacuum.
Basic Acoustics + Digital Signal Processing January 11, 2013.
Harmonics October 28, Where Were We? Mid-terms: our goal is to get them back to you by Friday. Production Exercise #2 results should be sent to.
Breathy Voice Note that you can hear both a buzzy (periodic) component and a hissy (aperiodic) component.
Harmonic Motion Mr. Villa Physics.
© 2014 John Wiley & Sons, Inc. All rights reserved.
For a periodic complex sound
Sound & Sound Waves.
Presentation transcript:

Speech Science V Akustische Grundlagen WS 2007/8

Recapitulation Airstream production (pulmonic, glottal or velaric airstreams serve as a basis for speech sound production) The kinetic airstream energy can be transformed into acoustic energy at various points along the vocal tract. The first point at which the transformation can occur is at the glottis (the space between the vocal folds) The acoustic energy is periodic if the vocal folds vibrate, aperiodic if they are constricted but do not vibrate

Topics What are sounds physically? Periodic signals - sinusoids Damping - phonation Complex waveforms Reading: a) Kent, Ch. 2, b) Borden, Harris & Raphael, Ch. 3, 24-44/31-53 Deutsch: c) Pompino-Marschall, Teil II, Ch. 2, d) Reetz, Ch. 2, 3-32

Air-particle movement Acoustic energy = fluctuating pressure uniform pressure state (all particles equidistant local disturbance moves P1 close to P2 (local pressure increase) P2 moves away from P1, thus moving closer to P3

Condensation & rarifaction Pressure changes travel (at the speed of sound!) The pressure change in one area is transmitted to the next …. so the sound moves from its origin and is heard elsewhere This process is called “sound propagation“

Periodic signals A disturbed air particle oscillates through its resting point and back (just like any other vibrating system):

The sinewave The oscillations follow a strict pattern which can be described with a sinusoid function

D = A sin Ωt where Ω = 2 π/T Calculating the amplitude The momentary amplitude D is determined by the position on the circumference (which is equivalent to the angle  of the radius line to that point): D = sin  or: D = A sin 2 π t/T or: = position on the circumference of the circle. (which changes with time)

Loss of energy (damping) Any “real-world“ vibration will die out because of energy loss (friction)! The more energy loss, the more quickly the signal dies out (the more strongly damped it is) Logarithmically and linearly damped signals

What has this to do with speech? The acoustic energy from the vocal-fold vibrations is strongly damped Each glottal closure adds energy to the system, which quickly weakens. Negative pressure is created by the abrupt closure of the vocal folds. The oscillation is visible during the closed phase, but the damping is greater in the open phase

Damped glottal cycles Idealized, different degrees of damping would effect the speech signal as the following figure shows In both signals the glottal impulse renews the energy after 5 oscillations, but in the left signal damping is weak and the oscillations have continued strongly; in the right signal damping is strong and the oscillations have almost died out.

Complex signals What aspect of the glottal signal oscillates (and is therefore damped)? The glottal signal is NOT a single sinusoid (i.e. not energy at one single frequency) When the vocal folds vibrate and come together (each glottal cycle), they produce an impulse with harmonic energy These “harmonics“ are vibrations at every multiple of the fundamental glottal frequency F0 = 100 Hz; Harmonics = 100, 200, 300, 400, 500, 600 ……. Hz

At any point in time, the overall amplitude (energy) is the sum of the component amplitudes What do complex signals look like? E-synth demo

How complex is the glottal signal? The glottal flow signal is like a rounded sawtooth wave This gives a frequency distribution (spectrum) with all harmonics of the fundamental (F0) present with decreasing power (-12dB per octave)

Is the glottal signal like a sawtooth? A square wave has the odd-numbered harmonics The sawtooth wave has every harmonic

Summary Local fluctuations of air pressure (air-particle proximity) = acoustic energy These are propagated at the speed of sound Repeated patterns of pressure change are „periodic signals“ The simplest waveform is the sinusoidal wave, which can be described with a simple mathematical function Complex waves can be described as a sum of simple waves The glottal wave is the sum of all the harmonics of the fundamental frequency The glottal wave is very heavily damped; each glottal closure brings fresh energy into the system.