Ocean Matrix OMX-01HMBT0013 Operation Manual page 9

Audio Embedding and De-embedding:
The Transmitter supports audio embedding and de-embedding. The L/R IN/OUT port
can be used for audio embedding or de-embedding through the L/R IN/OUT switch.
TX Audio Embedding:
When the L/R IN/OUT switch is switched to left, the audio from external audio devices
will be embedded to the L/R IN/OUT port.
TX Audio De-embedding:
When the L/R IN/OUT switch is switched to right, The L/R IN/OUT port will output the
audio de-embedded from the HDMI IN port.