An Explosion Two recording devices are set 2400 feet apart, with the device at point A to the west of the device at point B At a point between the devices 300 feet from point B a small amount of explosive is detonated. The recording devices record the time until the sound reaches each. How far directly north of point B should a second explosion be done so that the measured time difference recorded by the devices is the same as that for the first detonation? | Numerade

Audio Recording: Definition and Process

Push Button Recordable Sound Chips | Record and Play Multiple Files

This Day in History: Thomas Edison files a patent for the first phonograph

'St. Louis tinfoil' | Historic sound recording inducted into Library of Congress registry