Yealink SIP-T2 SERIES Administrator's Manual page 807

Parameters
Custom.
Web User Interface:
Settings->Tones->Message
Phone User Interface:
None
voice.tone.autoanswer
Description:
Customizes the warning tone for auto answer.
The value format is Freq/Duration. For more information on the value format, refer to
the parameter ―voice.tone.dial‖.
Note: It works only if the value of the parameter ―voice.tone.country‖ is set to
Custom.
Web User Interface:
Settings->Tones->Auto Answer
Phone User Interface:
None
To configure tones via web user interface:
1. Click on Settings->Tones.
2. Select the desired value from the pull-down list of Select Country.
If you select Custom, you can customize a tone for each condition of the IP phone.
3. Click Confirm to accept the change.
Configuring Audio Features
Permitted Values
String
Default
Blank
785