Learning objectives
Understanding the physics of sound, causes and effects of the acoustic phenomenon, fundamental quantities, and measurement units.
Knowing the mechanisms of sound propagation in open and closed environments and the physiological and psychological phenomena that regulate its perception.
Knowing the equipment and the calculation techniques for recording, processing, and analyzing common sound and noise phenomena, to assess their extent, any disturbance or damage caused, and compliance with legal limits.
Course unit content
Physical Acoustics: sound propagation mechanism, definition of the fundamental quantities: amplitude, period, frequency, wavelength, speed of the sound wave.
Energy Acoustics: sound pressure, particle velocity, acoustic intensity, energy density, sound power, impedance.
Psychoacoustics: mechanisms of humans’ sound perception. Frequency weighting curves, loudness evaluation techniques, time/frequency masking phenomena.
The logarithmic scale of decibels (dB), elementary operations on quantities expressed in dB.
Sound level meter (SLM), equivalent level, calibration of a SLM.
Different types of audio signals, constant band frequency analysis, percentage band (octaves, etc.) frequency analysis, critical band (barks) frequency analysis.
Sound propagation: spherical source, directivity, linear source, discrete source (streets).
Outdoor propagation: temperature gradient and wind effects, air absorption, designing of noise shields. Environmental noise legislation, night level, day level, differential level, impulse correction, tonal correction, d-e-n level.
Indoor propagation: reflection, absorption and transmission coefficients, sound-absorbing and sound-insulating materials, apparent sound absorption coefficient, reverberant and semi-reverberant field, critical distance, sound tail, reverberation time and Sabine's formula.
Impulse response of an environment and impulse response measurement techniques.
Single Event Level (SEL) and Personal Exposure Level (LEP). Measurement / calculation of SEL and LEP.
Bibliography
Free Italian texts, downloadable in PDF from the Rockwool website (thanks!):
- Patrizio Fausti: Acustica in Edilizia, Rockwool Italia, Milano (2005)
- Arianna Astolfi e Maria Giovannini: Acustica delle aule scolastiche, Rockwool Italia, Milano (2012)
Other texts:
- R. Spagnolo (ed.): ACUSTICA, Fondamenti e applicazioni - Casa Editrice: UTET Università - Anno: 2015 - ISBN: 9788860084460
- Thomas D. Rossing (ed.): Springer Handbook of Acoustics, Springer Science + Business Media, New York (2014) - ISBN: 9781493907540
Teaching methods
Frontal lectures and exercises.
The material presented during the lectures (slides) is made available in advance on the Elly platform.
Assessment methods and criteria
Oral exam with open theory questions and numerical calculus exercises. The use of texts and supporting material is not allowed. You will need: calculator, sheet of paper, pencil.
