Wave Pitch Crest Loudness Intensity Frequency Amplitude Trough Ultrasonic Wavelength Infrasonic Compression Mechanical Wave Rarefaction Hertz or Hz 1. A periodic disturbance that moves away from a source and carries energy with it. 2. The highest point of a wave. 3. The distance between adjacent crest or troughs. 4. A process in which the air molecules moved closer to each other. 5. It is the height of a wave. 6. It is the lowest point of a wave. 7. Sounds with frequencies beyond 20 000 Hz are described as 8. Sounds refer to those with frequencies of lower than 20 Hz. 9. As the air molecules moved apart, it creates bending movement. 10. A wave that requires a medium to propagate. 11. It refers to the amount of energy of a sound wave. 12. The quality of the sound. 13. It is the highness or lowness of sound. 14. SI units and symbol for decibel. 15. It is the number of waves passing a given point.​