A proposed general definition is that the sound emitted by such PCs should not exceed 30 The Sound of Music | sound recording and reproduction | Puget Sound | Long Island Sound | sound film | sound | McMurdo Sound | Ministry of Sound | The Sound of Music (film) | King George Sound | Sound recording and reproduction | pressure | Owen Sound | Sound film | sound design | Sound | National Film and Sound Archive | Prince William Sound | Academy Award for Best Sound | sound barrier | Negative pressure ventilator | The Sound and the Fury | Sneaky Sound System | The Sound | Muscle Shoals Sound Studio | University of Puget Sound | The Sound of Silence | Standard conditions for temperature and pressure | Speed of sound | Sound of Fire | Similar
In acoustics, the sound pressure of a spherical wavefront radiating from a point source decreases by 50% as the distance r is doubled; measured in dB, the decrease is still 6.02 dB, since dB represents an intensity ratio.
In a medium of density ρ for a plane or spherical free wave having a velocity of propagation v, the sound energy flux through the area A corresponding to an effective sound pressure p is
Following this flight, Crossfield and NACA pilots Joseph A. Walker and John B. McKay flew the aircraft for such purposes as to gather data on pressure distribution, structural loads, and structural heating, with the last flight in the program occurring on 20 December 1956, when McKay obtained dynamic stability data and sound-pressure levels at transonic speeds and above.
Except in extremely low pressure loads, the exiting propellant gasses generate much higher sound pressure levels (dBa) than any other aspect of the weapon firing.
According to Rayleigh II the sound pressure is determined in each point of a half-space, if the sound pressure in each point of its dividing plane is known.