Where it borns
If the vibrations of a source is emitted and propagated in air then it is called airborne sound. Conversation, singing, shouting, sounds emitted by animals, sounds of wind instruments and strings (instruments) that do not touch floor, the sound of thunder are the examples to airborne sounds.
- Machinery noise; due to lifts, plumbing, heating, ventilating and ariconditioning (HVAC) systems
- Impact noise; objects dropping on the floor, footsteps etc.
- Vibrations due to heavy vehicles
Mixture of airborne and structureborne sounds
Most of the sources cause both airborne and structure borne sounds.
It is important to know where the sound is borne because noise control techniques for airborne and structureborne sounds are completely different.