Acoustic and Instrumentation I

Knowledge at the level of 12th grade Math curriculum. Operations with complex numbers.

The curricular unit comprises:

– 1 theoretical class of 2 hours per week, where the teacher of the theoretical matrix briefly exposes the programmatic contents of the discipline;

– 1 theoretical-practical class of 1 hour per week, where the teacher applies the physical concepts presented in the theoretical class to the understanding of practical examples belonging to the universe of the Environmental Health professional, and introduces the student to the application of these concepts in problem solving;

– 1 theoretical-practical class of 1 hour per week, where students proceed to the resolution accompanied by practical application exercises formulated within the universe of the Environmental Health professional in order to clarify and relate the subjects addressed in the theoretical component, as well as to confer effective competencies in the analysis and resolution of real problems.

The curricular unit of Acoustics and Instrumentation I aims to provide the students a solid basis with regard to concepts of electroacoustics and signal analysis, necessary to achieve the learning outcomes proposed in the training plan of the Audiology course of ESTES Coimbra. A special emphasis will be given to the physical concepts applied to the electrical and electronic operation of electroacoustic systems, spectral decomposition of electrical and sound signals, and major signal processing operations.

The Curricular Unit of Acoustics and Instrumentation I will allow students to:

Assimilate the general concepts of electronics and electroacoustics applicable to the area of audiology;

Classify, distinguish and characterize the different types of transducers;

Assimilate the basic principles of analog signal processing;

Characterize and identify the main components of the equipment that is used in audiology;

1. Electricity and electronics fundamentals (37 hours)

Electric current – electric current intensity; electrical resistance and Ohm’s law; direct current circuits: voltage and current sources, association of passive components, Kirchhoff laws.

Alternating current (ac) – fasorial representation of alternating current and sinusoidal voltage; RC, RL and RLC circuits; Resonance in series and parallel RLC circuits; concepts of impedance and electrical admittance;

Generalised impedance/admittance: parallelism between acoustic, mechanical and electrical systems. Practical case: Clinical evaluation of acoustic admittance.

Passive filters: frequency response.

Operational amplifiers.

Amplifiers: harmonic and intermodal distortion, simplified amplification system, limitation – feedback, maximum acoustic gain.

2. Signal and System Processing Fundamentals (23 hours)

Digital Signals vs. Analog Signals:

   – Process of converting an analog signal into digital

   – Various types of digital signals

   – Digital signal processing systems

Fundamental Concepts of Signal Processing: Sampling, Aliaising, Normalization, Segmentation, Windowing.

Convolution. Fourier Theorem. Fourier transforms.

Description of a non-harmonic signal: time and frequency spectra, quantification by effective values (RMS);

Modulation; Noise;

Properties of linear and nonlinear systems;

NAO

Main bibliography:

HAUGHTON, Acoustics for Audiologists

Publisher: Academic Press

Edition: 2002

SPEAKS, Introduction to Sound (3rd edition)

Publisher: Singular Publishing Group

Edition: 1999

Secondary bibliography:

ROSEN e HOWELL, Signals and Systems for Speech and Hearing

Publisher: Academic Press

Edition: 2001