Mixed signal mode can only be used if the USB is connected to the audio conferencing computer and not the 3.5mm jacks. With this configuration, you can connect the 3.5mm audio-out jack to a transmitter, which can be used to connect to recording devices (for applications such as lesson capture audio or presentation recording) and hearing aid transmitters. In this mode, both near-end and far-end audio will be recorded or sent to the hearing aid transmitter.

The default signal provided by the HDL300 system’s output jack is microphone pickup that is echo-canceled. The signal is intended for the far-end conference site. However, when a local user connects a hearing aid transmitter or a recording device in the near-end room, the user will want to hear the far-end conversation as well as the near-end. Therefore, when mixed signal mode is activated, the HDL300 system will configure the auxiliary output jack so the user will receive both in-room (near-end) and remote audio (far-end) directly through the connected transmitter.

Mixed signal mode does not affect the auxiliary output levels. Additionally, it does not affect any other operation or function of the HDL300 system, including system volume or the quality of the audio.

When using a hearing aid transmitter with mixed signal mode, the user will receive both in-room and remote audio directly through the hearing aid.  Users must supply their own hearing aid transmitters for use with this feature.

For more information about using mixed mode, see our using the auxiliary ports article.