Reflector does not currently have the ability to record your voice with your device. Reflector will only record audio that is transmitted from the device. If you would like to add extra audio, you will need to use video post-processing software. Follow this issue more closely here.
Recording with Mac
Recording on OS X requires at least OS X 10.7 Lion. Recording on OS X 10.6 is not available.
Recording on Mac can be started/stopped from the device menu or by pressing ⌘+R.
Alternatively, you can select Start Recording from the Reflector device menu.
To stop the recording, press ⌘+R again or select Stop Recording from the device menu.
When you stop the recording, you'll be prompted to save the movie file. This window also gives you the option to include frames with the recording.
Recording with Windows
Recording for Windows requires at least Windows 7. Windows version 1.3.4 added recording for Windows 8.
Windows recording can be started/stopped by pressing ALT+R.
Alternatively, you can select Start Recording by right clicking on the mirrored device.
To stop recording, press ALT+R again or select Stop Recording from the right-click menu.
When you stop the recording, you'll be prompted to save the movie file. Unlike the Mac version, it is not currently possible to save frames with recordings.
Recording with Android
Reflector for Android is designed as a light-weight version of Reflector for Windows and Reflector for Mac. At this time, it does not support recording.