This FAQ describes how to connect bell button to the 2N® Indoor Talk. With bell button it is possible to call to the 2N® Indoor Talk directly without using any other devices. Upon pressing the door button 2N® Indoor Talk starts ringing based on the configuration.
Connect 2-wires bell button to the 2N® Indoor Talk.
Please go to web page - Services - User Sounds and set Sound Mapping according to your need, you can upload your own sound as well.
To modify sound volume please go to web page - Hardware - Audio and set Phone Call Volume according to your need.