Double Degree in Electronic Systems Engineering in Communications and Management of ICTS La Salle Campus Barcelona

Double Degree in Electronic Systems Engineering in Communications + in Engineering in the Management of ICTs

La Salle Campus Barcelona offers 5 double degrees in the ICT Engineering field. With the double degrees, you can finish the university studies in 5 academic years with two official degree qualifications.

Fundamentals of Acoustics and Audio

Description
The course aims at introducing the students to the fundamentals of audio and vibroacoustics. The first semester begins with some basic concepts such as the decibel scale and the characterization of harmonic waves. It introduces as well some topics on physiological acoustics and psychoacoustics. The basic theory of transducers is also presented, and both sensors (microphones and accelerometers) and actuators (loudspeakers) are considered. The second semester contains more physic and mathematic aspects. It includes acoustic and lineal vibrations fundamentals. Then the continuous system is analyzed, posing the wave equation for strings and membranes. After that, the wave equation in fluids is posed and the sound propagation in conducts and the radiation in free field are studied. Finally the sound generation and its radiation due to the surfaces radiation are tackled.
Type Subject
Optativa
Semester
Annual
Credits
6.00

Titular Professors

Previous Knowledge

Some calculus and algebra basic knowledge is required such as trigonometry, integration theory and derivatives, differential equations, problem matrix formulation, determinants and inverse matrices computation.

It is highly recommended to attend to this course at the same time that Physics, Statistics and Mathematical Analysis and Signal and Transmission Systems courses.

Objectives

The course aims to the acquisition of the foundations of sound and acoustics, and a basic knowledge of receiving and emitting the sound transducers. Also intends to acquire the basics of acoustic propagation, reflection and transmission between different media.

All this is intended to prepare students with the knowledge needed to deal with more specific areas related to acoustics: acoustic enclosures, Acoustic measurements, electroacoustics, environmental noise, acoustic engineering.

Contents

SEMESTER 1: INTRODUCTION TO AUDIO

1. Introduction: basic concepts of acoustic and sound
1.1. Period, frequency, wavelength
1.2. RMS/peak, intensity/power, dBs
1.3. Propagation of plane and spherical waves
1.4. Octave bands
1.5. Frequency analysis
1.6. Reflection, absorption, diffraction
1.7. Doppler efect

2. Physiological acoustics and psychoacoustics
2.1. Sound types and their characterization. Introduction to human hearing
2.2. The human ear: outer, middle and inner ear
2.3. Critical bands, isophonic curves and masking
2.4. Sound pressure level and weighting curves
2.5. Formants. Speech. Timbre

3. Receiving acoustic transducers
3.1. Electromechanical analogies and mecanico-acusticas
3.2. Theory of signal transduction
3.3. Classification of microphones
3.4. Characteristics of microphones
3.5. Types of microphones
3.6. Calibration of microphones
3.7. Design of accelerometers
3.8. Characteristics of accelerometers

4. Acoustic transducers emitting
4.1. Dynamic loudspeakers
4.2. Loudspeaker cabinets
4.3. Bass - réflex
4.4. Active - passive
4.5. Electroestatic speakers
4.6. Other types of speakers
4.7. Headset
4.8. Horns

SEMESTRE 2: INTRODUCTION TO VIBROACOUSTIC vibro-acoustic

5. Uniparametric continuous systems:
5.1. Ideal string in free regime
5.2. Ideal string in forced regime
5.3. Bar vibration
5.4. Vibration of rectangular membranes
5.5. Vibration of circular membranes

6. Sound waves in fluids
6.1. The wave equation
6.2. Propagation of plane waves in a tube
6.3. Transmission and reflection of plane waves
6.4. Introduction to acoustic filters
6.5. Propagation outdoors

7. Spherical waves in an open field
7.1. The wave equation
7.2. Specific impedance
7.3. The pressure and speed with distance attenuation
7.4. Acoustic intensity and acoustic energy density
7.5. Directivity

8. The sound radiation
8.1. The pulsating sphere
8.2. Dual source
8.3. Linear formation of point sources in phase
8.4. The dipole
8.5. Speaker performance
8.6. Horn radiation
8.7. Free field and reverberant field
8.8. Absorption from the air

Methodology

Theoretical explanation of the issues in dialogue with the students.
Discussion and exercises in groups during class time
Proposal of new exercises for personal study
Realization of experiences of laboratory in groups of two or three students

Evaluation

Continuous assessment from all the exercises in class, the realization of laboratory practices and two checkpoints in the middle of each semester.
Regular assessment by personal examination at the end of every six months the results of continuous assessment.
Extraordinary assessment during the month of July for those who have not reached the appropriate level of the regular valuation.

Evaluation Criteria

Continuous assessment shall be weighted at 40% each semester. This note is calculated from the three elements: exercises in class, practices of laboratory and point of control in equal parts.
The end of semester exam will be weighted at 60%. In this exam is required to achieve at least a 3.5 out of 10 to approve the regular valuation.
The final grade is calculated by averaging the two semesters provided that they had approved separately.
If one or two semesters have not been approved, a special test is performed during the month of July.

Basic Bibliography

Chapters 1 and 2:
- Handbook for sound engineers, 3rd Edition. Glen M. Ballou. Focal Press.
- The Art of Digital Audio, 3rd Edition. John Watkinson. Focal Press

Chapters 3 and 4:
- Fundamentals of Acoustics, 4th Edition. Lawrance E. Kinsler. Wiley & Sons.
- Loudspeaker and Headphone Handbook, 3rd Edition. John Borwick. Focal Press.
- Technical Documentation: Microphone Handbook. Vol. 1.: Theory. Bruel &Kjaer 1996
- Piezoelectric Accelerometers and Vibration Preamplifiers. Theory and Application Handbook. Bruel &Kjaer 1987.
- Introducción a Electroacústica. Federico Miyara PDF.

Chapters 5 to 8:
- Fundamentals of Acoustics, 4th Edition. Lawrance E. Kinsler. Wiley & Sons
- Sound and Structural Vibration (Radiation, Transmission and Response). Frank Fahy, Academic Press.
- Sound, structures and their interaction. Miguel C. Junger and David Feit. The MIT Press.

Additional Material

The students have all presentations in classes, the solved exercises proposed and practices scripts.