The most likely culprit here is older firmware. So the first step is to download the latest version from our site:
If this noise remains, please make a video recording with clear audio and send an email to Soma support at [email protected]. Please include firmware version and the algorithm you were using when recording the video.
And if you are using the pitch version, at lowest quality settings some digital artefacts may occur, this is inherent to how the algorithm works at half speed or lower.