Help removing high pitched ringing sound from voice recording

Hi, I am wondering if anyone can please help me remove this high pitched ringing sound from my audio recording.

I am running Windows 7 Home Premium 64 bit with Service Pack 1. I am running Audacity 2.2.2.

Here is a brief sample of the sound.

(Apologies for the political nature of the voice recording, this sample just happens to be a very good example of the problem.)

This recording is from an archive I am working with and was recorded about 4 years ago. I do not know what equipment was used. My best assumption is that the equipment was one of those electronic lectern setups like in universities but if so then I don’t think it was a very good lectern because the general audio quality is so disappointing. I don’t have high hopes for improving the clarity of the recording, I would just like to remove aspects that interfere most in the immersiveness of the recording, mainly this ringing sound.

Compression and noise removal have removed a lot of this ringing sound from across the recording, but as you can hear, this sound still remains on parts of the recording. I have tried using the high pass filter and the equaliser to remove it but I have been fiddling with this on my own for a couple of weeks and am struggling to get anywhere.

This is part of a one-off career project that will improve my quality of life a great deal and I would like to get the project as polished as I can, so any suggestions about how to get rid of this annoying sound would be much appreciated. Thank you very much for reading my question.

I couldn’t do it either. I was hoping to be able to find one or two feedback tones to suppress, but the room echoes just killed me. Once you build auditorium echoes and reverb into a performance it becomes a “record it again” problem.

And Hollywood does do that. If we get a terrible live field performance, we’ve been known to record the words again in a quiet studio and substitute the clean version in the show.


Try these notch filters in Audacity’s Nyquist prompt

(setf *track* (notch2 *track* 1957 50))
(setf *track* (notch2 *track* 2200 50))
(setf *track* (notch2 *track* 2737 50))
(setf *track* (notch2 *track* 3457 50))
(setf *track* (notch2 *track* 4260 50))
(highpass8 *track*  20)

notch filter code pasted into Nyquist prompt.png

They reduce the ringing, but don’t address the other problems.

Thank you for the replies, I am very grateful. I won’t get a chance to try the settings until the weekend but I just wanted to thank you.

That notch filter code is specific to the example you posted.
If the position of the mic is changed during the lecture, (e.g. if it is hand-held and the lecturer moves about),
the pitch of the ringing will change and those notch-filters won’t match.

This week I delivered my project to an enthusiastic reception. I’m so grateful to this product and community. Without Trebor’s solution the audio would not have been possible for an audience to listen to, so my project would not have had any chance of success. What this means for me is that I have achieved a competitive portfolio in the job market, because I have conceived, proposed, lead, developed, and delivered a project that is complete with a pilot. Sorry I have not posted properly about it yet but my circumstances cause me to have a lot of hectic priorities. Not sure what the thread closing policy is here but hope this thread will remain open for me to post 1 more piece of information about how the audio turned out. Thank you

what the thread closing policy is here

The thread will be closed (or even removed) if the poster is seen to be trying to sell us anything or use the forum itself as a business opportunity.

Sometimes the thread will be closed or frozen if the questions are only remotely having to do with Audacity. Recommendations for headphones or microphones sometimes fall in this category.

Sometimes a thread will be closed when the poster needs help with law enforcement, surveillance or conflict resolution. Conflict can extend to presentations from people advocating governmental change or political revolt, for example.


Threads are sometimes closed (as [SOLVED]) if there is a good answer to a question that others may have (so as to avoid the answer being buried under other posts).

Threads may be closed if they are, or are likely to attract a lot of spam responses (particularly questions like “what is the best …”)

Mostly topics are left open.