I'm no expert, but I can see two ways this might be done:
(1) Record a chunk of tone in a separate WAV file. (You can download a TONE GENERATOR for free (click TOOL -> TONE GENERATOR). Then copy-and-paste chunks of it into your program in place of the "sensitive information."
(2) Highlight the sensitive information, then (with the free Tone Generator running) press the RECORD button, which will record tone for as long as you want. Let it run for about the length of time your original sensitive information. It won't "exactly" replace the select time length -- if you highlight 5 seconds, and leave the record function "on" for 10 seconds, it will open up the original highlight section from 5 seconds to 10 seconds.
There may be other, better ways. I live to learn. In the meantime, I hope this helps.
Jerry