HPR4618: Simple Podcasting - Episode 2 - Basic Filtering

Hosted by Whiskeyjack on 2026-04-15 01:00:00

---

HPR Comments

---

Antoine says: Applying filters - exp. with declicking - Compression?

RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack
00:37:16 Listen in ogg, opus, or mp3 format.
Worthy content! (for use and "for the fun of it"). Actually, as an Audacity user, may not use the command-line editing, but the underlying concepts are the same.
About de-esser, maybe it's better to apply it to the excerpts one need (or want) to improve. With my first uses of click removal, I liked it so much that applied to the entire recording. The result : almost no audible clicking, but a lot of lost missing "t"s in some phonemas. (Best is to don't click the tongue, but, if not, there is declicking — for specific regions.)
I don't remember using de-esser you presented, but the idea may be the same, to check the result where applied.
Aaand, I shall wait for the entire series, but one tool that I would like to listen to is compression. Let's see whether it is going to be adressed on the shows or not, anyway, thanks for sharing.

---

Vance says: Click removal

RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack
00:37:16 Listen in ogg, opus, or mp3 format.
Antoine, thanks for mentioning the click removal capability in Audacity! While I already knew about its noise removal filter, I wasn't aware it also had click removal.

It might have helped me for HPR4637, where some sort of electromagnetic signal was picked up by my microphone/recorder, a Zoom H2 (the tapping sound was *not* present in the room where I recorded).

While click removal does seem to distort speech when applied to it (though to my ears, it doesn't sound as weird as when noise removal is done with speech), I could have applied the filter only to the pauses, where the "tapping" is most noticeable. I will consider doing this in the event that I'm not able to eliminate the source of interference in the future, which would be the best way to go.

---

Vance says: To Whiskeyjack - Click Removal

RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack
00:37:16 Listen in ogg, opus, or mp3 format.
Thanks for your ideas! Looking at the Ogg/Opus/MP3 files on HPR, I see that they have some additional noise during pauses that makes the click removal filter in Audacity less effective. On the original WAV file, I *was* able to remove most of the tapping noise by applying that filter to pauses with a Threshold value of 50 and a Max Spike Width of 30. Trying the same values on pauses in the MP3 file was less effective, but did improve things a little bit.

I agree that applying the click filter to the sections where I'm speaking produces undesirable distortion. It would be possible to manually highlight just the pauses and remove clicks from each one, but that would be tedious. I considered blanking out those areas, but it would be just as tedious and I thought it might sound weird for there to be total silence.

However, your suggestion of using ffmpeg's agate filter would eliminate the problem of having to manually highlight the pauses. I see that it doesn't totally zero out the waveform, just reduces it, so it shouldn't sound weird.

I would be happy to send you a WAV or FLAC file to play around with, and you are welcome to use as much of this episode as you like in your own work. E-mail me at the address on my host page.

Initial testing seems to indicate that it was likely my mobile phone that caused the problem to begin with. If that is the case, it's easy enough to get rid of the problem at its source by moving it away from the microphone (it was in my shirt pocket) or just turning it off.

---

Whiskeyjack says: Reply to Vance in HPR4618 - Click Removal

RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack
00:37:16 Listen in ogg, opus, or mp3 format.
I had a look at your HPR 4637 episode to see what the "clicks" were like. I did some experiments to try to find a technique which could remove the clicks.

The "click removal" effect in Audacity does nothing useful to deal with this. The same was true for most of a number of other common filter techniques that I tried. The ones which did have an effect on the clicks introduced noticeable distortion in the voice which was more of a problem than the clicks.

What does work is the "noise gate" effect (which is agate in ffmpeg). You set a threshold in dB and any part of the signal which falls below that level is suppressed to zero. In other words, quiet parts of the audio are made quieter. I set a threshold of -20dB and all of the clicks were completely removed without introducing distortion in the voice signal.

In a few spots, short initial syllables on a few sentences were also cut out, but I didn't spend any time adjusting parameters to get it perfect. I suspect that another solution to this would be to not apply the effect on those few parts of the audio where this happens.

Would it be alright with you if I used a short (5 second) clip of your podcast as a noise sample in my own upcoming episode on audio filtering? This is not a noise problem that I can easily recreate and it would make for an interesting problem and solution to address.

The more I look at things the more I am convinced that there is no one size fits all solution to audio problems, only collections of tools that we can keep in our toolboxes.

---

Whiskeyjack says: Reply to Vance on Click Removal in HPR4618

RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack
00:37:16 Listen in ogg, opus, or mp3 format.
I already have the 5 second audio sample that I need from your HPR 4637 episode from the MP3 release, but I thought it would be polite to ask you first before using it as we were already corresponding in these comments.

I have most of the script written for a new HPR episode and will begin recording the dialogue and making the audio samples used to illustrate each point. I will describe in detail what I did to the sample from your podcast in that episode and show a before and after example.

This new episode is entirely inspired by comments from listeners, and your comment describing a click problem provided a very interesting subject for discussion in it. Thank you for your feedback on this.

---

Whiskeyjack says: Response to Antoine on de-essing in HPR 4618

RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack
00:37:16 Listen in ogg, opus, or mp3 format.
I knew absolutely nothing about audio before making my first two HPR episodes.

I learned a little bit about filtering in order to try to fix audio noise problems I noticed in those ones before making the 8 part series which followed.

Most of what I know now has come about from having to address the subject more systematically while making this 4 part series.

There is still a lot I don't know, including how to use audio compression properly.

I had never even heard about de-essing until I started making this series. I found out about it while researching filters.

I am currently making a follow up episode which concentrates on filtering methods and what sorts of noise situations each method may be useful in when making a podcast. So far it looks like there are pros and cons to different methods depending on the situation rather than there being a panacea which fixes all audio problems.

So far as clicks go, the recording method that I use of making many small segments and then stitching them together rather than speaking fluidly and continuously seems to inherently need de-essing more because the clicks seem to be most common when you start speaking from a resting state. Given this situation, I have some ideas that I may try which address this specifically rather than using de-essing.

I will add compression to the list of experiments that I will do. We'll have to see if I come up with any useful results.

I am currently about to go buy a new microphone to create a new category of recording set up to collect test samples.

Thank you for your feedback. I got the idea for this project from a comment by an HPR listener on a previous episode.

Mastodon Comments