SMC Networks SMC3056EM - Manual (Page 13)

13
3.6 Connecting Microphone And Speaker
You could either use a handset connected to the EZ Modem,
or connect a microphone and a speaker for voice recording
and playback.
NOTE:
Any commercially available microphone is usable.
For the speaker, any 8 ohm speaker rated around 1Watt
can be driven directly by the audio output. An amplifier
is required if you need a higher output volume.
1. Connect the microphone to the mini-phone jack marked
MIC.
2. Connect the speaker to the mini-phone jack marked
SPK.