| A | B |
|---|
| larynx | two folds of tissue that make up the human voice box (p.41) |
| elasticity | the ability of a material to bounce back after being disturbed (p.43) |
| density | ratio of the mass of a substance to its volume (p.43) |
| intensity | the amount of energy per second carried through a unit area by a wave (p.46) |
| loudness | perception of the intensity of a sound (p.47) |
| decibel | unit of measurement of loudness (p.47) |
| ultrasound | sound wave with frequency above 20,000 Hz (p.48) |
| infrasound | sound wave with frequency below 20 Hz (p.48) |
| pitch | perception of the frequency of a sound (p.48) |
| Doppler effect | the apparent change in frequency of a sound as the source moves in relation to the listener (p.50) |
| timbre | the overall quality of a sound (p.53) |
| music | a set of tones and overtones combined in ways that are pleasing to the ear (p.54) |
| noise | a mixture of sound waves with no pleasing timbre and no identifiable pitch (p.55) |
| dissonance | the sound produced when notes that have no musical relationship are played together (p.55) |
| acoustics | the study of how well sounds can be heard in a particular room or hall ( p.58) |
| beats | the regular changes in loudness of a sound when two sounds of different frequencies are played together (p.59) |
| ear canal | a narrow region leading from the outside of the human ear to the eardrum (p.62) |
| eardrum | a small, tightly stretched, drum-like membrane in the ear (p.63) |
| middle ear | the space behind the eardrum (p.63) |
| cochlea | a fluid-filled cavity behind the inner ear (p.63) |
| sonar | a system of detecting reflected sound waves (p.67) |
| echolocation | the use of reflection of sound waves to navigate and to locate prey (p.68) |
| sonogram | an image formed by an ultrasound machine (p.69) |
