These are representations of the HHT display:

Operator 1 has entered Bus Action Mode, and has selected Intercom Bus 6 for "Talk & Listen" mode, represented by the "T" in the Activity/Bus Mode row. This image also shows that Operator 1 is in PTT talk mode, with the volume and sidetone set to levels of "5" each.

This shows that Operator 1 has chosen Intercom Bus 8 for quick "Talk & Listen" using a Hot Key (Hot Key Talk & Listen is represented on the display by the "#" sign). To quickly access a single intercom bus, the operator simply presses that number on the keypad.

See the links in the right-hand sidebar for additional operator interface options.