In this area, you have the option to start a meeting by clicking on the Start instant meeting button (see section 3.2.1, page 10). TeamViewer 9 Manual – Meeting of 63 Host Meeting The Host Meetings area. If you're using a different OS, and the client software has the ability, then again, it's going to be in the preference options.
If you are using a third party app, if it can bring the audio, there's going to be an preference option for it.