Pure tone: single-frequency sound rarely occurs in nature.Ĭomplex sound: sound comprising more than one frequency. Human ear capable of hearing from approximately 20 to 20,000 Hz. Hertz (Hz): in acoustics, unit to express frequency (formerly cycles per second or cps). Time for completion of one cycle is the period. One-tenth of a Bel (named for Alexander Graham Bell).įrequency: number of cycles (complete oscillations) of a vibrating medium per unit of time psychoacoustic correlate is pitch. Sound pressure: sound force (related to acceleration) over a surface per unit time.ĭecibel (dB): unit to express intensity of sound more specifically the logarithm of the ratio of two sound intensities. Intensity of sound: amount of sound energy through an area per time refers to sound strength or magnitude. In psycho acoustics, sounds with higher amplitudes are perceived as louder than sounds with lower amplitude. Sound: energy waves of particle displacement, both compression (more dense) and rarefaction (less dense) within an elastic medium triggers sensation of hearing by vibrating the tympanic membrane.Īmplitude of sound: extent of vibratory movement from rest to farthest point from rest in compression and rarefaction phases of energy waves.