Talk Calls
The Talk feature is very similar to what is also known as a Direct Intercom: it allows the user to speak immediately with another Nomad User without the need for any notification.
The Talk call option is available via the User Contact Key:

It will be automatically established in the Talk Box.

The initiator of the call has the Mic open allowing him to immediately speak, while the recipient has his Mic closed but it can be opened at any time to respond

The Talk Call can be closed after the conversation or kept in the Talk Box (just like an Open Line) for further use.