How to remove steady 2K Tone from speech recording

Dear Engineers:
Can you tell me how I can 1)isolate and 2) remove the high-pitched tone (in the attached audio clip). Seems to be about 2000hz but low volume.

I would also like to get rid of the room reverberation but that is a separate question in another topic.

Dear Engineers:
Attached is a snippet of a recording of a speech that was taped in a very live room. Way too much reverberation.
How can I get rid of this reverberation?

Thanks in advance!

We can suppress the whine and some of the background noise, but I think you’re stuck with the echo/reverb.

Somebody else may post. Echo/reverb is one of the reliable ways to kill a show.


This is Noise Reduction 12, 6, 6 using the quiet snippet at 5.5 seconds as the profile. If I go higher than that, the voices will fall apart.

There is no echo/reverb filter that I know of.


De-reverb plugins can only dry-up slight reverb, and they add digital artefacts …

Echoes or reverb is the performer’s voice bouncing from the walls, ceiling and floor and arriving at the microphone late—after the original voice. And not just once. Several different delays depending on the size and dimensions of the room. So you are asking the software to remove the performer from himself, many thousand times.

That’s why we didn’t come racing to your rescue when you asked that question. And that’s why reverb/echo is one of the four horsemen of audio recording.

The Four Horsemen of Audio Recording (reliable, time-tested ways to kill your show)
– 1. Echoes and room reverberation (Don’t record the show in your mum’s kitchen.)
– 2. Overload and Clipping (Sound that’s recorded too loud is permanently trashed.)
– 3. Compression Damage (Never do production in MP3.)
– 4. Background Sound (Don’t leave the TV on in the next room.)

There is a Hollywood way to rescue a performance with that kind of damage. Write down the words and either have the original performers say them again in a quiet room, or hire actors to do it in a quiet room. This looping and overdubbing happens in more movies than you think.

You should go through this once to rescue the show and cure you of ever shooting sound that way again.


The tone has multiple harmonics that are at multiples of 485 Hz, as can be seen by the horizontal lines in the track Spectrogram view

The frequencies may be seen using “Plot Spectrum

This code in the Nyquist Prompt will remove those tones:

;version  4

(do ((hz 485 (+ hz 485)))
    ((>= hz 20000) *track*)
  (setf *track* (notch2 *track* hz 80)))