Acoustics

Acoustics is a branch of physics that studies sound, or more precisely, mechanical waves in gases, liquids, and solids. It is concerned with the production, control, transmission, reception, and effects of sound. A scientist who works in the field of acoustics is called an acoustician. The application of acoustics in technology is called acoustical engineering. There is often much overlap and interaction between the interests of acousticians and acoustical engineers.

Knowledge gained through the field of acoustics has had great significance for applications related to artistic expression. The development of acoustic technology has also been important in the study of geologic, atmospheric, and underwater phenomena. In addition, ultrasound technology has led to important developments in medicine.

Background

The word acoustic is derived from the ancient Greek word ακουστός, meaning able to be heard ^[1]

The study of acoustics has been fundamental to many developments in the performing arts. Many of the principles of acoustics, especially in the area of musical scales and instruments, were explained theoretically by scientists only after long years of experimentation by artists. For example, much of what is now known about architectural acoustics was learned by trial and error over centuries of experience and only recently formalized into a science.

From a scientific viewpoint, sound waves are a form of mechanical vibrations (or mechanical waves). When the ear receives these waves, the signals are transmitted to the brain, which interprets them as sound. The study of sound waves led to the discovery of physical principles that can be applied to the behavior of all mechanical waves. Acoustics, therefore, involves the study of mechanical vibrations in general and the potential applications of the knowledge gained in modern life.

…[A]coustics is characterized by its reliance on combinations of physical principles drawn from other sources; and that the primary task of modern physical acoustics is to effect a fusion of the principles normally adhering to other sciences into a coherent basis for understanding, measuring, controlling, and using the whole gamut of vibrational phenomena in any material.

F. V. Hunt^[2]

Divisions of acoustics

The following are the main fields of acoustics:^[3]

• General Acoustics: the science of sound and waves; includes Engineering Acoustics, Physical Acoustics, and Signal Processing in acoustics
• Animal Bioacoustics: study of how animals make, use and hear sounds; includes Acoustical Oceanography, Animal Bioacoustics, Underwater Acoustics
• Architectural Acoustics: study of how to design buildings and other spaces that have pleasing sound quality and safe sound levels; includes Architectural Acoustics, Engineering Acoustics, Physical Acoustics, Structural Acoustics and Vibration
• Medical Acoustics: use of acoustics to diagnose and treat different types of ailments; includes Biomedical Acoustics, Engineering Acoustics, Speech Communication, Noise
• Musical Acoustics: the science of how music is made, travels and is heard; includes Musical Acoustics, Psychological and Physiological Acoustics, Noise
• Noise and Environmental Acoustics: study of natural and man-made noise; includes Noise, Structural Acoustics and Vibration, Speech Communication
• Speech and Hearing: study of how our ears sense sounds, what types of sounds can damage our ears and how speech is made, travels, and is heard; includes Speech Communication, Physiological and Psychological Acoustics, Noise
• Underwater Acoustics: study of sounds moving through water; includes Underwater Acoustics, Acoustical Oceanography, Animal Bioacoustics, Physical Acoustics

Applications

As noted earlier, the study of acoustics has been of fundamental importance for developments in the arts. Other applications of acoustics technology are in the study of geologic, atmospheric, and underwater phenomena. Psychoacoustics, the study of the physical effects of sound on biological systems, has been of interest since Pythagoras first heard the sounds of vibrating strings and hammers hitting anvils in the sixth century B.C.E. However, the application of modern ultrasonic technology has only recently provided some of the most exciting developments in medicine.

Daniel Statnekov and others have recently been studying the effects of sound on the human brain. Harmonic frequencies in the form of binaural beats can affect the brainwave patterns of a person who plays an ancient Peruvian Whistling Pot to create a "trance state."^[4]

Notes

References

ISBN links support NWE through referral fees

• Beranek, Leo L. Acoustics. New York, NY: American Institute of Physics, 1954. ISBN 088318494X
• Malcolm J. Crocker. Encyclopedia of Acoustics. Hoboken, NJ: Wiley, 1997. ISBN 0471804657
• Hunt, Frederick V. Origins in Acoustics: The Science of Sound from Antiquity to the Age of Newton. New Haven CT: Yale University Press, 1978. ISBN 0300022204
• Kent, Raymond D. Acoustic Analysis of Speech, 2nd Edition. San Diego, CA: Singular Publishing Group, 2001. ISBN 0769301126
• Morfey, Christopher L. Dictionary of Acoustics. San Diego, CA: Academic Press, 2001. ISBN 0125069405
• Morse, Philip M., and K. U. Ingard. Theoretical Acoustics. New York, NY: McGraw-Hill Education, 1968. ISBN 0070433305
• Pickett, J. M. The Acoustics of Speech Communication: Fundamentals, Speech Perception Theory, and Technology. Upper Saddle River, NJ: Allyn & Bacon, 1998. ISBN 0205198872
• Pierce, Allan D. Acoustics: An Introduction to its Physical Principles and Applications. New York, NY: American Institute of Physics, 1989. ISBN 0883186128
• Stevens, Kenneth N. Acoustic Phonetics. Cambridge, MA: The MIT Press, 1999. ISBN 026219404X
• Woodhouse, S. C. English-Greek Dictionary: With a Supplement of Proper Names Including Greek Equivalents for Famous Names in Roman History. (first published in 1910) Abingdon, UK: Routledge, 1972. ISBN 0415151546

External links

All links retrieved April 13, 2021.

• Acoustical Society of America
• Institute of Acoustics in UK
• National Council of Acoustical Consultants
• Institute of Noise Control Engineers