The app will then take the median frequencies of your voice to give you your general range. Depending on the app, you may be able to record anywhere from 30 seconds to 3 minutes, generally singing the song of your choice. If you use an app to find your vocal range, you will be directed to record your voice using your phone's microphone.You can also find your vocal range by recording and listening to yourself as you sing. There are a number of apps and websites with rangefinder tools that can help you determine your natural range in a matter of minutes. To give yourself the best shot possible when evaluating your singing voice, you first need to find your vocal range.