NEC SL1000 Features And Specifications Manual page 236

SL1000
To talk Handsfree after initiating Group Listen:
1. Hang up the handset.
To cancel Group Listen (without hanging up your call):
1. Do not hang up.
2. Press the flashing Speaker.
You can talk to the caller over the handset. Your co-workers can no longer hear the caller's voice.
G
1-228
ISSUE 1.0
Group Listen