Google Hangouts has been improving their noise detection algorithm for voice and video calls. Users can now type while the noise detection algorithm will just filter out the noise instead of muting and will keep users on the line.
Normally, the voice and video calls on Google Hangouts would mute users altogether if typing was detected and users have to hop back into the Hangout in order to unmute themselves. This is really inconvenient for users if they are taking notes or working on the side. Hence, this new upgrade will definitely will be for the better. Nevertheless, users have to keep in mind that this update is only for Google Hangouts on the web.
Source: Android Central