Acoustics and Audio Systems
FEKT-PAZSAcad. year: 2017/2018
The course Acoustics and Audio Systems is focused to deepen the theoretical knowledge in the field of acoustics and electro-acoustics and teaching of analysis and synthesis of 2D and 3D sound fields using physical and perceptual principles and compression and transmission of multi-channel audio signals. The course also covers the basics of experimental psycho-acoustics, room acoustics and sound reinforcement issues.
Learning outcomes of the course unit
On completion of the course, students are able to:
- describe the frequency and directional characteristics of ideal sound sources,
- explain the principles of spatial and directional hearing,
- employ devices for multi-channel capture and reproduction of sound,
- describe methods of propagation of sound in an enclosed space and describe methods of simulation of the propagation,
- enumerate and explain the principles of sound field analysis methods based on perceptual and physical principles,
- explain the principle of sound field synthesis using WFS, ambisonic and VBAP,
- design a listening test for assessing the quality of audio devices and algorithms for processing and compression of audio signals
- explain the principles of lossy compression of audio signals including compression of spatial sound formats,
- explain the principles of line sources and principle of phasing sound systems and design sound reinforcement for specific rooms.
The knowledge of basic physical laws is required as well as the knowledge of laws and quantities in electrical circuits, characteristics of electric circuit elements, circuit behaviour with inertia elements, periodical and non-periodical signal spectra, random variables and basic terms from the area of statistics, acoustics and electro-acoustics. Students who enrol on the course should be able to use instruments for the measurement of electrical quantities, sound recording and reproduction technology and sound level meters and have basic knowledge of Matlab.
Recommended optional programme components
Recommended or required reading
Bosi, Marina: Introduction to Digital Audio Coding and Standards. 2003. ISBN 1-4020-7357-7
Spanias, Andreas: Audio Signal Processing and Coding. 2007. ISBN 978-0-471-79147-8
Gardner, William G.: 3-D Audio Using Loudspeakers. 1998. ISBN 0-7923-8156-4
Williams, Earl G.: Fourier Acoustics : Sound Radiation and Nearfield Acoustical Holography . 1999. ISBN 0-12-753960-3
Zölzer, Udo.: DAFX: Digital Audio Effects. 2011. ISBN 978-0-470-66599-2
Planned learning activities and teaching methods
Techning methods include lectures and computer laboratories. Course is taking advantage of e-learning (Moodle) system.
Assesment methods and criteria linked to learning outcomes
Evaluation of study results follow the BUT Rules for Studies and Examinations and Dean's Regulation complementing the BUT Rules for Studies and Examinations. Up to 20 points are awarded for the test in the computer exercises. Up to 20 points can be obtained for programming and defense of the individual project. Up to 60 points are given for the final written examination, and it is necessary to get at least 20 points for its successful completion. The exam consists of 10 groups of questions in the field of acoustics and electro-acoustics according to the course syllabus, with one question selected from each group.
Language of instruction
1. Sound propagation, wave equation.
2. Characteristics of ideal sound sources.
3. Analysis and synthesis of 2D and 3D sound fields - physical principles 1: beamforming, NAH.
4. Analysis and synthesis of 2D and 3D sound field - physical principles 2: wavefield synthesis.
5. Metatheory spatial hearing, spherical harmonic decomposition, formats for tranfer of spatial information (A-format, B-format, UHJ).
6. Analysis and synthesis of 2D and 3D sound fields - perceptual principles 1: ambisonic.
7. Analysis and synthesis of 2D and 3D sound fields - perceptual principles 2:, SIRR, Dirac.
8. Basics of experimental acoustics, standards, evaluation methods.
9. Lossy compression of audio signals 1: principles MPEG Layer 1,2,3 standards.
10. Lossy compression of audio signals 2: SBR, spatial information coding, MPEG 2 BC, AAC, AC3, ATRAC, MPEG Surround standards.
11. Room acoustics, method of mirror sources, raytraycing.
12. Acoustic materials, designing sound studios in terms of acoustics, standards.
13. Sound reinforcement, line sources, phasing of sound systems.
The aim of the course is to introduce students with modern advanced methods of capturing, processing, compression, transmission and spatial representation of audio signals and methods of assessing the auditory perception of the listener.
Specification of controlled education, way of implementation and compensation for absences
It is obligatory to prepare and defend individual project in Matlab to complete the course. Other forms of checked instruction are specified by a regulation issued by the guarantor of the course and updated for every academic year.