Acoustics

science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound

Acoustics is a science. It studies the mechanical waves in gases, liquids, and solids. These waves can make echo, vibration, sound, ultrasound and infrasound.

A scientist who works in the field of acoustics is an acoustician. Someone who works with acoustics technology may be called an acoustical engineer.