Course detail

Electroacoustics

FEKT-BELAAcad. year: 2017/2018

Acoustic environment, sound propagation, basic quantities and relations, energy transmitted by sound. Physiological acoustics, sound masking and its utilization in compression algorithms, directional and spatial hearing. Noise and its measurement. Room acoustics, room impulse response. Electromechanical and electro-acoustic analogy, acoustic materials and structures. Types and operation principles of electro-acoustic transducers. Microphones, practical design and measurement of characteristics. Loudspeakers, acoustic impedance and distortion, mechanical design, horn-loaded loudspeakers, headphones. Loudspeaker systems, types of loudspeaker enclosures, design and construction of loudspeaker systems and crossovers. Multichannel audio systems, basics of sound reinforcement. Stereo and multichannel techniques of sound pickup.

Language of instruction

Czech

Number of ECTS credits

5

Mode of study

Not applicable.

Learning outcomes of the course unit

On completion of the course, students are able to:
- enumerate the basic acoustic quantities and their units,
- explain the physiology of hearing, including binaural auditory perception,
- employ sound level meters and use them for noise and electro-acoustic measurements,
- describe room acoustic properties, demonstrate the measurement of room impulse response and reverberation time, enumerate materials and structures used for modifying the room acoustics
- categorize electro-acoustic transducers and state their principles, properties and use,
- categorize microphones, state their properties and designs, and demonstrate the measurement of their characteristics,
- describe the properties of designs used for unloaded and loaded loudspeakers, measure and calculate their parameters,
- design loudspeaker systems and measure their characteristics,
- enumerate the types of surround sound systems and describe their principle,
- enumerate the methods of multichannel sound pickup and explain their principles.

Prerequisites

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. Students who enrol on the course should be able to use instruments for the measurement of electrical voltage, current, and resonant frequency, waveform generators, and oscilloscopes.

Co-requisites

Not applicable.

Planned learning activities and teaching methods

Teaching methods depend on the type of course unit as specified in article 7 of the BUT Rules for Studies and Examinations.
- Lectures provide explanations of the basic principles, subject methodology, examples of problems and their solutions.
- Laboratory exercises support practical mastering of the themes presented in lectures. Active participation of students is required.
Participation in lectures is recommended. Participation in other ways of instruction is checked.
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 tests in theoretical knowledge in the laboratory exercises. Up to 20 points can be obtained for correct results and elaboration of all laboratory exercises. The minimal scope of the elaboration of a particular laboratory exercise and the complementary questions are specified by a regulation issued by the guarantor of the course and updated for every academic year. Up to 40 points are given for the final written examination, and it is necessary to get at least 15 points for its successful completion. Up to 20 points are given for the final oral examination and it must be done on the same day as the written examination. The exam consists of 10 groups of questions in the field of acoustics and electro-acoustics according to the course syllabus.

Course curriculum

1. Acoustic environment, basic quantities and relations, wave equation of sound propagation, energy transmitted by sound, sound spectrum. Types of acoustic fields.
2. Physiological acoustics, subjective and objective properties of sound, sound masking and its utilization in audio compression algorithms.
3. Directional and spatial hearing, 3D room simulation using headphones and loudspeakers.
4. Noise and its measurement, noise clases, loudness measurement according to Steven's and Zwicker's models.
5. Sound level meters, analyzers for electroacoustic measurements, calibration of measurement chain. Measurement of acoustic power and sound intensity.
6. Basics of room acoustics,geometric, wave and statistic models, room impulse response, measurement of reverberation time, objective parameters of listening rooms.
7. Electromechanical and electro-acoustic analogy, acoustic materials and structures.
8. Electro-acoustic transducer as the system, types and operation principles of transducers.
9. Gradient microphones, wave and combined microphones, design and measurement of characteristics.
10. Loudspeakers, acoustic impedance and distortion, mechanical design, horn-loaded loudspeakers. Types and design of headphones, measurement of characteristics.
11. Loudspeaker systems, types of loudspeaker enclosures, design and construction of loudspeaker enclosures and crossovers. Acoustic lenses.
12. Multichannel sound reproduction, basics of sound reinforcement.
13. Stereo and multichannel techniques of sound pickup.

Work placements

Not applicable.

Aims

The aim of the course is to make students familiar with the chain of processing acoustic signals from their origination through their transformation into electric signals and back to acoustic signals up to the listener's final perception.

Specification of controlled education, way of implementation and compensation for absences

It is obligatory to undergo all laboratory exercises in regular or alternative terms 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.

Recommended optional programme components

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

SCHIMMEL, J. Elektroakustika. Elektroakustika. Brno, Vysoké učení technické v Brně. 2013. p. 1 - 167. ISBN 978-80-214-4716-5.
Smetana, C. a kol. Hluk a vibrace, měření a hodnocení. Sdělovací technika, Praha 1998. ISBN 80-90-1936-2-5 (CS)
Škvor, Z., Akustika a elektroakusitka. Academia, Praha, 2001. ISBN 80-200-0461-0 (CS)

Recommended reading

Colloms, M., High Performance Loudspeakers, 6th ed. John Wiley & Sons, Ltd, 2005. ISBN 978-0-470094-30-3 (EN)
Eargle, J. The Microphone Book. 2004. ISBN 0-240-51961-2 (CS)
Sýkora, B. Stavíme reproduktorové soustavy, 1. – 48. díl. A Radio 10/97 - 9/2001 (CS)
Toman, K. Reproduktory a reprosoustavy, 1. díl. Dexon, 2003. (CS)

Classification of course in study plans

  • Programme EECC Bc. Bachelor's

    branch B-TLI , 2 year of study, summer semester, elective specialised
    branch B-EST , 2 year of study, summer semester, elective interdisciplinary

  • Programme AUDIO-J Bachelor's

    branch J-AUD , 2 year of study, summer semester, compulsory

  • Programme EEKR-CZV lifelong learning

    branch EE-FLE , 1 year of study, summer semester, compulsory

Type of course unit

 

Lecture

26 hod., optionally

Teacher / Lecturer

Syllabus

Acoustic environment, basic quantities and relations, wave equation of sound propagation, energy transmitted by sound, sound spectrum, acoustic impedance.
Physiological acoustics, sound masking and its utilization in audio compression algorithms.
Directional and spatial hearing, 3D room simulation using headphones and loudspeakers.
Noise and its measurement, basic measuring instruments for electroacoustic measurement and their application.
Measurement of acoustic power and sound intensity.
Room acoustics, acoustic wave trajectory, room impulse response, acoustic materials.
Electromechanical and electroacoustic analogy.
Types and operation principles of electroacoustic transducers.
Microphones, practical design and measurement of characteristics.
Loudspeakers, acoustic impedance and distortion, mechanical design, horn-loaded loudspeakers.
Loudspeaker systems, types of loudspeaker enclosures, design and construction of loudspeaker enclosures and crossovers.
Surround sound systems principles and formats.
Stereo and multichannel techniques of sound pickup.

Laboratory exercise

26 hod., compulsory

Teacher / Lecturer

Syllabus

Getting familiar with the laboratory and the safety regulations, getting familiar with operating laboratory equipment.
Sound signal spectrum
Measurement of ear's own characteristics
Measurement of binaural hearing characteristics
Noise measurement
Room acoustics measurement
Test
Calibration of the electrostatic microphone by pistonphone
Measuring the impedance characteristic of loudspeakers
Measuring the frequency response of microphones
Design and simulation of loudspeaker system
Measuring the frequency and directional response of loudspeaker system
Test