Another name for sound waves (vibrations). Ultrasonic waves and infrasonic waves are inaudible to humans and sub-sonic and supersonic waves travel very slow or fast. Acoustic waves travel at the speed of sound. Sound is measured on a spectrum based on the capacity for human hearing. Other animals capacity for hearing varies on the spectrum for example dogs are known to hear things that we cannot. (source: Smithsonian)

« Back to Glossary Index