Note 1 to entry: The duration of transmission is short compared to a specified duration of interest. In many cases, the relevant duration of interest is the maximum duration of flight from transmission to reception.

Note 2 to entry: Note that the use in underwater acoustics of the words "transmit", "transmitter" and "transmission" to describe the process of sound radiation by a source is commonplace, but this deviates from the usage prescribed in IEV 702-02-05 where the words "emit", "emitter" and "emission" are preferred.