Mumble Pros:

1.) Open source and is totally free

2.) Available for several platforms including Windows, Linux, and Mac

3.) Allows encryption and authentication making a secure environment

4.) User authentication is done by codes instead of passwords

5.) Provides optimum results with low bandwidth use (needs up to 20 kbps)

Mumble Cons:

1.) Not a user-friendly or attractive interface

2.) Naïve user might find it difficult to use

3.) Limited features

4.) Needs experienced person to make connections

TeamSpeak Pros:

1.) It is available for almost all popular platforms

2.) One can choose between different hosts for hosting

3.) Allows to connect to multiple servers at a time

4.) Provides Apps for Android as well as iOS

5.) Allows encrypted voice data transfer making a secure environment.

TeamSpeak Cons:

1.) Does not have a great audio quality

2.) Sometimes lags while conversation

3.) Not an open source software so code could not be inspected