* Introduction to Acoustics:
Explore the nature of sound, sound waves, their properties such as frequency and amplitude, and how they interact with our ears to create perception.
Each musical instrument produces a characteristic vibration. The vibrations spread through the air forming sound waves that, when they reach the ear, allow us to identify the instrument, even if we cannot see it. The four examples shown represent typical waveforms of some common instruments.
A tuning fork generates a pure sound, and vibrates regularly with a rounded waveform. A violin generates a clear sound and a jagged waveform. The flute generates a soft sound and a relatively rounded waveform. The tuning fork, violin, and flute play the same note, so the distance between the wave maxima is the same in all waveforms. A gong does not vibrate regularly like the first three instruments. Its waveform is jagged and random, and you usually cannot recognize the note.
Sound is defined as the physical phenomenon that stimulates the sense of hearing. In humans, this occurs whenever a vibration with a frequency between about 15 and 20,000 hertz reaches the inner ear. The hertz (Hz) is a unit of frequency that corresponds to one cycle per second. These vibrations reach the inner ear transmitted through the air, and sometimes the term “sound” is restricted to transmission in this medium.
However, in modern physics the term is usually extended to similar vibrations in liquid or solid media. Sounds with frequencies higher than about 20,000 Hz are called ultrasounds.
This chapter deals with this field of physics in general terms. For matters relating to the architectural science of the design of rooms and buildings with adequate sound propagation and reception properties. Regarding the nature of the physiological process of hearing sounds and the anatomy of the hearing mechanism in people and animals.