Linked from
The 10 pages that link to Sound pressure, each with the reason it gives.
MicrophoneRelated: It is the physical quantity most microphones detect directly.
LoudspeakerRelated: The loudspeaker's radiated sound is measured as pressure variation in air.
SoundRelated: Pressure fluctuations are one way sound travels through air.
DecibelRelated: Sound pressure is the field quantity underlying sound pressure level.
Outer earRelated: The outer ear channels pressure variations toward the eardrum.
ClappingRelated: The transient pressure peak gives a clap its audible sharpness.