Audio is over-modulated resulting in noticeable distortion that negatively impacts the viewing experience.
Check your source. If this sounds ok, then it's possible that the audio levels were adjusted at some point, possibly during ingestion of the tape master (tape deck was misconfigured), during an edit (audio mixer of the non-linear editor was incorrectly adjusted), or during transcoding (a gain filter was applied).
Return to the point in your workflow where you are able to verify the audio was ok and start re-processing from that point. If you have to take it into an NLE to perform an edit ensure the NLE is configured correctly and when retranscoding ensure no gain filters have inadvertently been applied to the profile being used.
If the issue exists on your source then seek an alternate master, or alternate audio stems which you can use to replace the affected audio.
If you are unable to provide a better audio source please contact your Netflix representative via Backlot.