10.1 The receiver output should be suitable for
use with a loudspeaker or a telephone handset. The audio output should
be sufficient to be heard in the ambient noise level likely to be
encountered on board ships.
10.2 It should be possible to switch off the loudspeaker
without affecting the audio output of the telephone handset, if provided.
10.3 In the transmit condition during simplex
operation, the output of the receiver should be muted.
10.4 In the transmit condition during duplex operation,
only the telephone handset should be in circuit. Care should be taken
to prevent any electrical or acoustic feedback, which could cause