TANDBERG 7000 MXP - Manual (Page 147)

Administrator Settings
147
4.4.3 AAC-LD 128kbps (stereo audio)
Specify a call rate for 128kbps AAC-LD. From this call rate and above, "128kbps AAC-LD" is
available. On lower call rates "64kbps AAC-LD" is available.
Stereo audio requires twice the bandwidth as mono CD-quality audio. Therefore we recommend
to enable stereo audio on high call rates only. To enable stereo CD-quality audio you need to
specify a call rate for when stereo automatically should be enabled. On lower call rates, mono
CD-quality audio "64kbps AAC-LD" will be enabled.