Course detail

Measurements for Audio and Acoustics

FEKT-MPC-AMAAcad. year: 2021/2022

The subject is focused on measurements of audio equipment, acoustic and electroacoustic measurement according to international recommendations in these fields. Laboratory practices are focused on the realization of projects in LabView and Matlab for the automated measurement of audio equipment, electroacoustic devices and noise in various industrial measuring systems and bulk processing of measured data, especially using VBA programming language. In laboratory exercises, the Brüel & Kjaer, Audio Precision and NTi Audio measuring systems are used.

Language of instruction

Czech

Number of ECTS credits

6

Mode of study

Not applicable.

Learning outcomes of the course unit

- use the correct method for automated measurement of a given quantity,
On completion of the course, students are able to:
- create an automated measurement project for typical applications in acoustics, electroacoustics and audio engineering,
- perform bulk processing of measured data using a spreadsheet editor,
- create and edit macros in the VBA for bulk processing of measured data,
- create functions in VBA for remote control of automated measurement systems.

Prerequisites

Knowledge of principles and control of instruments for measuring voltage, current and frequency, knowledge of the operation of digital generators, oscilloscopes and spectral analyzers, knowledge of principles of measurement of current, voltage, frequency, impedance and total harmonic distortion, knowledge of C language and work with spreadsheet editor are required.

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 40 points can be obtained for elaboration of all individual work and laboratory exercises and in order to be awarded a credit, it is necessary to obtain at least 1 point from each individual work and laboratory task. 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 60 points are given for the final examination, and it is necessary to get at least 30 points for its successful completion.
In the case of distance learning, laboratory excercises are replaced by homework evaluated with the same number of points. The exam will take place in person, in justified cases remotely.

Course curriculum

1. Analysis of sound signals: Fourier analysis, order analysis, constant percentage bandwidth analysis, frequency weighting filters, weight filters for noise measurement. Statistical analysis of measurements, steady state measurements, averaging of values and smoothing of waveforms.
2. Methods of sound systems analysis: closed and open loop measurements, narrowband and wideband measurement signals, MLS, TDS methods and two-channel spectral analysis, spectrum analysis using bandpass filters and DFT, analysis of nonlinear systems. Equalization and compensation of measuring chain delay.
3. Measurement of audio devices: terminology and calculation methods according to IEC 60268-1, measurement of amplifiers according to IEC 60268-3, measurement of digital audio devices according to AES17, measurement of multichannel devices.
4. Measurement of acoustic quantities: measurement environment, anechoic, semi-anechoic and reverberation chamber, measurement of emission levels of sound pressure, measurement of noise and noise exposure, measurement of sound intensity, measurement of acoustic power by measuring intensity and by integration of sound pressure, noise sources identification
5. Sound level meter: microphone, preamplifier, quality classes of sound level meters; calibration of the measuring chain - acoustic, electroacoustic, reciprocal calibration, calibration in free and diffusion field.
6. Measurement uncertainties, basics of metrology – measurement devices, standards, calibration and verification.
7. Measurement of microphones: impedance, sensitivity, frequency and directional characteristics, nonlinearity, dynamic range, measurement of microphone parameters according to IEC 60268-4.
8. Loudspeaker measurement: near and far field measurement, loudspeaker installation, test signals, impedance, sensitivity, frequency and directional characteristics, harmonic, differential, modulation and rub & buzz distortion, loudspeaker parameter measurement according to IEC 60268-5, TS parameter measurement.
9. Measurement of headphones: construction of headphones, acoustic impedance of the ear and its simulation, types of ear simulators and their properties, measurement of headphone parameters according to IEC 60268-7.
10. Subjective methods of quality and comprehensibility evaluation: C-V-C tests, RT and DRT tests, MOS, ABX, ABS, MUSHRA methods; practical implementation of tests. Objective methods of assessment of quality and intelligibility: articulation index, evaluation of speech intelligibility by speech transmission index according to IEC 60268-16, perceptual approach to sound and speech quality assessment.
11. - 13. Professional lecture - case studies of measurements in acoustics, electroacoustics and measurement of audio equipment.

Work placements

Not applicable.

Aims

The aim of the course is to introduce students to modern methods and devices for measurements in acoustics, electroacoustics and audio technology.

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

BRIXEN, E., B. Audio Metering - Measurements, Standards and Practice, 2nd edition. Focal Press, 2011. ISBN: 978-0-240-81467-4 (EN)
AES17-2015, AES standard method for digital audio engineering - Measurement of digital audio equipment. Audio Engineering Society, Inc., 2015. (EN)
BALLOU, Glen. A sound engineer´s guide to audio test and measurement. Amsterdam: Elsevier, Focal Press, 2009, vi, 179 s. ISBN 978-0-240-81265-6. (EN)

Recommended reading

Not applicable.

eLearning

Classification of course in study plans

  • Programme MPC-AUD Master's

    specialization AUDM-TECH , 2. year of study, winter semester, compulsory-optional
    specialization AUDM-ZVUK , 2. year of study, winter semester, compulsory-optional

Type of course unit

 

Lecture

26 hours, optionally

Teacher / Lecturer

Laboratory exercise

39 hours, compulsory

Teacher / Lecturer

eLearning