Course detail

Measurements for Audio and Acoustics

FEKT-MPC-AMAAcad. year: 2024/2025

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.

Guarantor

doc. Ing. Jiří Schimmel, Ph.D.

Department

Department of Telecommunications (UTKO)

Entry knowledge

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.

Rules for evaluation and completion of the course

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 45 points can be obtained for elaboration of all individual work and laboratory exercises. To be awarded credit, it is necessary to complete all laboratory exercises, complete all independent tasks and complete all laboratory tasks to a minimum extent. 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 55 points are given for the final examination, and it is necessary to get at least 25 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.

Aims

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

Study aids

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

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)
BRIXEN, E., B. Audio Metering - Measurements, Standards and Practice, 2nd edition. Focal Press, 2011. ISBN: 978-0-240-81467-4 (EN)

Recommended reading

Not applicable.

Elearning

eLearning: currently opened course

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 hod., optionally

Teacher / Lecturer

doc. Ing. Jiří Schimmel, Ph.D.

Syllabus

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. Sound pressure measurement, sound pressure emission levels, noise exposure, vibration measurement, loudness measurement, noise curves, health protection against adverse effects of noise.

4. Measurement environment, anechoic, semi-anechoic and reverberant chamber. Sound intensity measurement, acoustic power measurement using intensity measurement and integration of sound pressure, identification of noise sources.

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 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.

8. Measurement of microphones: impedance, sensitivity, frequency and directional characteristics, nonlinearity, dynamic range, measurement of microphone parameters according to IEC 60268-4.

9. 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.

10. 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.

11. 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.

12.-13. Professional lecture - case studies of measurements in acoustics, electroacoustics and measurement of audio equipment.

 

Laboratory exercise

39 hod., compulsory

Teacher / Lecturer

doc. Ing. Jiří Schimmel, Ph.D.

Syllabus

  • Getting familiar with the laboratory, introduction to VBA
  • Common laboratory exercises:
    • Data processing of sound level meter measurement using VBA
    • Audio device analysis and sequence measurement with the Audio Precision APx analyzer
    • Introduction to LabView
    • Controlling the Audio Precision APx Analyzer with LabView
    • Controlling the Audio Precision APx analyzer using Matlab
  • Individual projects: Acoustic power measurement
    • Measurement of TS parameters of loudspeaker
    • Measuring the characteristics of audio equipment
    • Open-loop measurement of communication devices
    • Measurement of compressor characteristics
  • Alternate term for laboratory exercises

Elearning

eLearning: currently opened course