How do you change the voice to make it unrecognizable? Let’s assume that for security reasons you need to protect somebody’s identity, they have recorded a piece of audio and your job is to make them sound different and more importantly ensure that the voice can’t be changed back. Here are some ideas for you!
Varied Pitch Shifting
Instead of a straight -6 semitone pitch shift use automation lines in the multitrack of Adobe Audition to vary the pitch shift up and down over time. This could still be undone if someone really knew what they were doing. Perhaps add some chorus with heavy modulation to make things harder. Can you tell this is Mike?
Varied Pitch Shift Sample
by Mike Russell
Here’s a screenshot of what we did in Adobe Audition:
Let’s try pitching this sample back up 6 semitones…
Pitch Shifting Un-Done
by Mike Russell
Oh no! I guess it’s on to method 2 for higher security 
Vocoding
A vocoder plugin is really hard to undo. The plugin I really like for vocoding a voice is called OVox 1. Here’s my voice with the Fat Boy preset added. Can you tell it’s me? This process can’t be easily reversed and you can experiment with various settings here too. So definitely a better option than above for security.
Vocoding Sample
by Mike Russell
Text to Speech
A final snip if you can’t use a voice actor just use an online text to speech tool such as Google Translate or Amazon Polly. The latter has better audio quality, allows you to download audio files and is almost free.
Best Voice Coding Method?
Over to you! Did you work with audio in the past that needed to be anonymized? What methods did you use? Share with us in the comments below!
