Acoustical engineering
Acoustical engineering (also known as acoustic engineering) is the branch of engineering dealing with sound and vibration. It includes the application of acoustics, the science of sound and vibration, in technology. Acoustical engineers are typically concerned with the design, analysis and control of sound.
One goal of acoustical engineering can be the reduction of unwanted noise, which is referred to as noise control. Unwanted noise can have significant impacts on animal and human health and well-being, reduce attainment by students in schools, and cause hearing loss.[1] Noise control principles are implemented into technology and design in a variety of ways, including control by redesigning sound sources, the design of noise barriers, sound absorbers, suppressors, and buffer zones, and the use of hearing protection (earmuffs or earplugs).
Besides noise control, acoustical engineering also covers positive uses of sound, such as the use of ultrasound in medicine, programming digital synthesizers, designing concert halls to enhance the sound of orchestras[2] and specifying railway station sound systems so that announcements are intelligible.[3]
Acoustic engineer (professional)
Acoustic engineers usually possess a
In most countries, a degree in
Subdisciplines
The listed subdisciplines are loosely based on the PACS (Physics and Astronomy Classification Scheme) coding used by the Acoustical Society of America.[8]
Aeroacoustics
Aeroacoustics is concerned with how noise is generated by the movement of air, for instance via turbulence, and how sound propagates through the fluid air. Aeroacoustics plays an important role in understanding how noise is generated by aircraft and wind turbines, as well as exploring how wind instruments work.[9]
Audio signal processing
Audio signal processing is the electronic manipulation of audio signals using analog and digital signal processing. It is done for a variety of reasons, including:
- to enhance a sound, e.g. by applying an audio effect such as reverberation;
- to remove unwanted noises from a signal, e.g. echo cancellation in internet voice calls;
- to compress an audio signal to allow efficient transmission, e.g. perceptual coding in MP3 and Opus
- to understand the content of the signal, e.g. identification of music tracks via music information retrieval.[10]
Architectural acoustics
Architectural acoustics (also known as building acoustics) is the science and engineering of achieving a good sound within a building.[11] Architectural acoustics can be about achieving good speech intelligibility in a theatre, restaurant or railway station, enhancing the quality of music in a concert hall or recording studio, or suppressing noise to make offices and homes more productive and pleasant places to work and live.[12] Architectural acoustic design is usually done by acoustic consultants.[13]
Bioacoustics
Bioacoustics concerns the scientific study of sound production and hearing in animals. It can include: acoustic communication and associated animal behavior and evolution of species; how sound is produced by animals; the auditory mechanisms and neurophysiology of animals; the use of sound to monitor animal populations, and the effect of man-made noise on animals.[14]
Electroacoustics
This branch of acoustic engineering deals with the design of headphones, microphones, loudspeakers, sound systems, sound reproduction, and recording.[15] There has been a rapid increase in the use of portable electronic devices which can reproduce sound and rely on electroacoustic engineering, e.g. mobile phones, portable media players, and tablet computers.
The term "electroacoustics" is also used to describe a set of electrokinetic effects that occur in heterogeneous liquids under influence of ultrasound.[16][17]
Environmental noise
Environmental acoustics is concerned with the control of noise and vibrations caused by traffic, aircraft, industrial equipment, recreational activities and anything else that might be considered a nuisance.
Musical acoustics
Musical acoustics is concerned with researching and describing the physics of music and its perception – how
Noise control
Noise control is a set of strategies to reduce
Psychoacoustics
Psychoacoustics tries to explain how humans respond to what they hear, whether that is an annoying noise or beautiful music. In many branches of acoustic engineering, a human listener is a final arbitrator as to whether a design is successful, for instance, whether
Speech
Speech is a major area of study for acoustical engineering, including the production, processing and perception of speech. This can include physics, physiology, psychology, audio signal processing and linguistics. Speech recognition and speech synthesis are two important aspects of the machine processing of speech. Ensuring speech is transmitted intelligibly, efficiently and with high quality; in rooms, through public address systems and through telephone systems are other important areas of study.[22]
Ultrasonics
Underwater acoustics
Underwater acoustics is the scientific study of sound in water. It is concerned with both natural and man-made sound and its generation underwater; how it propagates, and the perception of the sound by animals. Applications include
Vibration and dynamics
Acoustic engineers working on vibration study the motions and interactions of mechanical systems with their environments, including measurement, analysis and control. This might include:
Fundamental science
Although the way in which sound interacts with its surroundings is often extremely complex, there are a few ideal sound wave behaviours that are fundamental to understanding acoustical design. Complex sound wave behaviors include absorption, reverberation, diffraction, and refraction. Absorption is the loss of energy that occurs when a sound wave reflects off of a surface, and refers to both the sound energy transmitted through and dissipated by the surface material.[26] Reverberation is the persistence of sound caused by repeated boundary reflections after the source of the sound stops. This principle is particularly important in enclosed spaces. Diffraction is the bending of sound waves around surfaces in the path of the wave. Refraction is the bending of sound waves caused by changes in the medium through which the wave is passing. For example, temperature gradients can cause sound wave refraction.[27] Acoustical engineers apply these fundamental concepts, along with mathematical analysis, to control sound for a variety of applications.
Associations
- Acoustical Society of America Technical Committee on Engineering Acoustics
- Audio Engineering Society
- Australian Acoustical Society[28]
- Canadian Acoustical Association[29]
- Institute of Acoustics, Chinese Academy of Sciences
- Institute of Acoustics (United Kingdom)
- Danish Sound Cluster (Denmark)
See also
- Audio Engineering
- Category:Acoustical engineers
- Category:Audio engineers
References
- ^ ISBN 978-92-890-0229-5.
- ISBN 978-0419245100.
- ISBN 978-0415238700.
- ^ Education in acoustics. "MSc Engineering Acoustics, DTU". Retrieved 9 February 2018.
- ^ National Careers Service. "Job profiles: Acoustics consultant". Retrieved 13 May 2013.
- ^ University of Salford. "Graduate Jobs in Acoustics". Archived from the original on 6 March 2016. Retrieved 13 May 2013.
- ^ Acoustical Society of America. "Acoustics and You". Archived from the original on 2017-03-08. Retrieved 13 May 2013.
- ^ Acoustical Society of America. "PACS 2010 Regular Edition—Acoustics Appendix". Archived from the original on 2013-05-14. Retrieved 22 May 2013.
- ISBN 978-3639210644.
- ^ ISBN 9780071663472.
- ^ Morfey, Christopher (2001). Dictionary of Acoustics. Academic Press. p. 32.
- ISBN 978-0750605380.
- ^ a b National Careers Service. "Job profiles Acoustics consultant"..
- ^ "Acoustical Society of America Animal Bioacoustics Technical Committee. What is Bioacoustics? accessed 23 November 2017". ASA. Archived from the original on 6 June 2014. Retrieved 22 May 2013.
- ^ Acoustical Society of America. "Acoustics and You (A Career in Acoustics?)". Archived from the original on 2015-09-04. Retrieved 21 May 2013.
- ^ Dukhin, A.S. and Goetz, P.J. "Characterization of liquids, nano- and micro- particulates and porous bodies using Ultrasound", Elsevier, 2017
ISBN 978-0-444-63908-0
- ^ ISO International Standard 13099, Parts 1,2 and 3, "Colloidal systems – Methods for Zeta potential determination", (2012)
- ISBN 978-0415358576.
- ^ Technical Committee on Musical Acoustics (TCMU) of the Acoustical Society of America (ASA). "ASA TCMU Home Page". Archived from the original on 2001-06-13. Retrieved 22 May 2013.
- ISBN 978-0415487078.
- ^ University of Salford. "Making products sound better". Archived from the original on 2013-07-24. Retrieved 2013-05-21.
- ^ Speech Communication Technical Committee. "Speech Communication". Acoustical Society of America. Archived from the original on 4 June 2013. Retrieved 22 May 2013.
- ^ Ensminger, Dale (2012). Ultrasonics: Fundamentals, Technologies, and Applications. CRC Press. pp. 1–2.
- ^ ASA Underwater Acoustics Technical Committee. "Underwater Acoustics". Archived from the original on 30 July 2013. Retrieved 22 May 2013.
- ^ Structural Acoustics & Vibration Technical Committee. "Structural Acoustics & Vibration Technical Committee". Archived from the original on 3 November 2013. Retrieved 22 May 2013.
- ^ Barron, 2002, ch. 7.1.
- ^ Hemond, 1983, pp. 24–44.
- ^ "Australian Acoustical Society ABN 28 000 712 658 A.C.N. 000 712 658". www.acoustics.asn.au.
- ^ "Canadian Acoustics - Acoustique Canadienne". caa-aca.ca.
- Barron, R. (2003). Industrial noise control and acoustics. New York: Marcel Dekker Inc. Retrieved from CRCnetBase
- Hemond, C. (1983). In Ingerman S. ( Ed.), Engineering acoustics and noise control. New Jersey: Prentice-Hall.
- Highway traffic noise barriers at a glance. Retrieved February 1, 2010, from http://www.fhwa.dot.gov/environment/keepdown.htm Archived 2011-06-15 at the Wayback Machine
- Kinsler, L., Frey, A., Coppens, A., & Sanders, J. (Eds.). (2000). Fundamentals of acoustics (4th ed.). New York: John Wiley and Sons.
- Kleppe, J. (1989). Engineering applications of acoustics. Sparks, Nevada: Artech House.
- Moser, M. (2009). Engineering acoustics (S. Zimmerman, R. Ellis Trans.). (2nd ed.). Berlin: Springer-Verlag.