The History of Acoustics
Acoustics, one of the oldest branches of physics, originated with Pythagoras's
studies of music over 2,500 years ago. Scientific milestones abound in
Galileo Galilei (1564-1642) discovered the general principles of
sympathetic vibrations, or resonance, and the correspondence between
the frequency of vibrations and the length of a pendulum.
Leonhard Euler and Daniel Bernoulli's studies of vibrating cords
in the 18th century eventually led to the development of Fourier analysis,
one of the most important tools of mathematics and mathematical physics.
Sir Isaac Newton and Gottfried Wilhelm Leibniz independently developed
the theory of calculus, which in turn allowed the derivation of the
general wave equation by the French mathematician and scientist Jean
Le Rond d'Alembert in the 1740s.
Hermann von Helmholtz's On the Sensations of Tone As a Physiological
Basis for the Theory of Music (1863) made substantial contributions
to understanding the mechanisms of hearing and to the psychophysics
of sound and music.
John William Strutt's The Theory of Sound (1877/78), a monument of
acoustical literature, was the first treatise to examine questions
of vibrations, the resonance of elastic solids and gases, and acoustical
propagation in material media.
Jean Baptiste-Joseph Fourier, a 19th-century French mathematician,
established his theory about the analysis of a complex periodic wave
into its spectral components.
German physicist Georg Simon Ohm hypothesized that the human ear
is sensitive to these spectral components. His Law of Hearing stated
that the ear is sensitive to the amplitudes, but not the phases, of
the harmonics of a complex tone.
20th-century American physicist Wallace Sabine initiated the science
of modern architectural acoustics by finding ways to correct the acoustics
of noisy rooms.
Hungarian-born American physicist Georg von Békésy
validated Helmholtz's theory of hearing with his Experiments in Hearing
(1960), the classic of the modern theory of the ear.
Current branches of acoustical study consider the auditory
aspects of telephony, radio and sound reproduction (communications acoustics);
the behavior of sound waves in interior environments (architectural acoustics)
and exterior environments (environmental acoustics); and the nature of
speech and hearing (physiological acoustics).