Taming the Sharp Edges: How to Fix Plosives (‘P-Pops’) and Harsh Sibilance (‘S’ Sounds) for Free

You just finished the perfect take. Your delivery was passionate, your timing was on point, and you know the content is gold. You press play, lean back, and… BAM! A thunderous ‘P’ sound rattles your headphones. A piercing ‘S’ sound makes you wince. Your great recording is suddenly unlistenable. As of August 12, 2025, this frustration ends. Forget expensive plugins and complex tools. We are going to permanently fix these issues using nothing but clever technique and the free tools you already have. This is how you reclaim your audio and make every word sound clean, crisp, and professional.

Welcome to the Soundbooth. I’m your engineer, and today we’re tackling two of the biggest enemies of clear voice recordings: Plosives and Sibilance. These aren’t just minor annoyances; they are auditory signposts that scream ‘amateur recording’ to your listeners. But here’s the secret: every single professional, from NPR hosts to audiobook narrators, deals with them. The difference is that they have a system to eliminate them both at the source and in post-production. Today, you get that system.

Part 1: The 90% Solution — Prevention at the Microphone

Before we ever open a piece of software, let’s fix the problem where it starts: at your mouth. Nearly all severe plosives and a good portion of sibilance issues come down to microphone technique. Get this right, and you’ll barely need the rest of this guide.

The Plosive-Proof Mic Position

A plosive—that jarring ‘thump’ on ‘P’, ‘B’, and ‘T’ sounds—is literally a blast of air hitting your microphone’s sensitive diaphragm head-on. The microphone interprets this burst of wind as a massive, low-frequency sound wave. The solution is simple: get out of the direct line of fire.

Speak Across the Mic, Not Into It: Position the microphone at a 45-degree angle to your mouth, slightly to the side. Aim your voice just past the microphone, not directly into its capsule. The sound of your voice will still be captured perfectly, but the blast of air from your plosives will shoot harmlessly past it.
The Pop Filter is Non-Negotiable: A pop filter is a screen (mesh or foam) that sits between you and the microphone. It acts as a shield, dissipating the air from plosives before it can hit the diaphragm. They are inexpensive and arguably the single most important accessory for any vocal microphone.

Engineer’s Note (Air, Not Sound): It’s crucial to understand that a plosive isn’t a sound in the traditional sense; it’s wind. Your microphone is so sensitive it ‘hears’ that wind as a huge bass thump. By using a pop filter and speaking at an angle, you’re not changing the sound of your voice, you’re just redirecting the wind. It’s like dodging a punch while still being heard clearly across the room.

Your Gear & Acoustics FAQ

“Can I just use the foam ball that came with my mic?”

You can, but it’s not ideal. Those foam windscreens are primarily designed for outdoor use to block actual wind. They are less effective at stopping the targeted, high-velocity air blast of a plosive. More importantly, the thick foam can slightly muffle the high frequencies of your voice, making it sound less crisp. A nylon or metal mesh pop filter on a gooseneck is always the superior choice for studio recording.

“I don’t have money for a pop filter right now. Is there a DIY fix?”

Yes, and it works surprisingly well! Take an embroidery hoop (or bend a wire coat hanger into a circle) and stretch a pair of clean nylon stockings over it. One or two layers is perfect. Mount this contraption to your mic stand with some tape or a clamp, and you’ve got a functional DIY pop filter. It’s not pretty, but it absolutely works.

“Why are my ‘S’ sounds so harsh and piercing?”

This is called sibilance. It can be caused by a few things: 1) Your natural vocal timbre (some people just have more sibilant voices). 2) Mic proximity—the closer you are, the more pronounced it can be. 3) The microphone itself. Many affordable condenser mics have a slight ‘presence boost’ in the high frequencies to sound more ‘detailed’, but this can exaggerate ‘S’ and ‘Sh’ sounds. Our processing chain will fix this.

Part 2: The Soundbooth Session — Surgical Repair in Audacity

Even with perfect technique, a rogue plosive or a harsh ‘s’ can sneak through. Now we move into post-production. Open up your Digital Audio Workstation (DAW). We’ll be using Audacity because it’s free, powerful, and universal, but the principles apply to any software (Logic Pro, Reaper, Adobe Audition, etc.).

Your Audio Detective Assignment

First, we need to train your ears. Record yourself clearly saying these two sentences:

“Peter Piper picked a peck of powerful purple peppers.”

“Sally’s sister swiftly sells silver seashells.”

Now, listen back on headphones. On the first sentence, can you hear the low-end thump when you say “Peter,” “Piper,” and “powerful”? It will sound like someone bumping the mic stand. On the second sentence, listen for the ‘S’ sounds. Do they have a sharp, hissing quality that is louder and more piercing than the other words? That’s what we’re about to fix.

The Precision Vocal Repair Chain (in Audacity)

This is not a blanket effect you apply everywhere. This is a surgical process. We will target the problems and leave the good parts of your audio untouched. The order is important!

Step 1 (Fix Plosives): We use a High-Pass Filter to surgically remove the offensive low-frequency thump.
Step 2 (Fix Sibilance): We use a De-Esser to intelligently turn down the volume of *only* the harsh ‘S’ frequencies, and only when they get too loud.

Step 1: Performing Surgery on Plosives

Zoom in on your waveform where you said “Peter.” You will see the normal, symmetrical wave of your voice, and then a huge, lopsided spike that corresponds to the ‘P’ sound. That’s our target.

Using your cursor, select only the plosive spike. Zoom in as much as you need to be precise. You only want to select the single, ugly, lopsided part of the wave.
Go to the menu and select Effect > Graphic EQ. (In newer versions, this might be `Filter Curve EQ` which is even better, but Graphic EQ is universal).
We need to apply a High-Pass Filter. This filter lets all high frequencies ‘pass’ through untouched, but cuts out low frequencies. In Graphic EQ, you achieve this by pulling down all the sliders on the left side (the bass frequencies). Start by pulling down everything below 150 Hz all the way to the bottom.

Click ‘Preview’ to hear the change on just that selection. The ‘thump’ should be gone, but the ‘P’ sound should still be intelligible. If you cut too high (e.g., 300Hz), you’ll start to thin out the voice itself. For most male and female voices, a cut-off around 120-150Hz is the sweet spot. Once it sounds right, click ‘Apply’. Repeat this for every major plosive in your recording.

Engineer’s Note (The Scalpel vs. The Axe): Why are we doing this manually? Because a plosive is an isolated event. If you applied a high-pass filter to your entire vocal track, you’d remove the pleasant, low-end warmth from your *entire* performance just to fix a few half-second errors. By targeting just the plosive, we are using a scalpel to remove a mole, not an axe to chop off a limb. This is the difference between editing and engineering.

Step 2: Taming Harsh Sibilance with a De-Esser

Sibilance is different. It can occur on every ‘S’, ‘Sh’, ‘Z’, and ‘T’ sound, so fixing it manually would be a nightmare. For this, we use an automated tool called a De-Esser. It’s a specialized compressor that only listens to a specific band of high frequencies and turns them down when they cross a certain volume threshold.

Thankfully, Audacity has a built-in De-Esser. If you don’t see it under the ‘Effect’ menu, you may need to enable it from the `Plugin Manager` or download a free VST version like ‘LISP by Sleepy-Time Records’. For this tutorial, we’ll use the stock effect.

Select your entire vocal track this time.
Go to Effect > De-Esser.
You’ll likely see two main controls: Threshold (dB) and Frequency (Hz).
The Frequency is the ‘hiss’ region we are targeting. A great starting point for sibilance is around 6000 Hz (or 6 kHz). Some voices might sit a bit lower (4kHz) or higher (8kHz).
The Threshold tells the plugin when to act. Start with it high (e.g., -10 dB). Now, hit ‘Preview’. It’s probably doing nothing. Slowly lower the threshold to -15dB, -20dB, -25dB. You will reach a point where you can hear the harshest ‘S’ sounds becoming softer and less piercing.
Listen carefully! The goal is to tame the sibilance, not eliminate it. If you set the threshold too low, the person will sound like they have a lisp. Find the spot where the harshness disappears but the ‘S’ is still a clear and natural consonant. That’s your setting.

Click ‘Apply’. Now listen to your entire recording of “Sally’s sister swiftly sells silver seashells.” The difference should be night and day. It will sound controlled, professional, and easy on the ears.

Your Soundcheck Plan This Week

Knowledge is useless without practice. Turn this into a habit, and you’ll be fixing these issues in seconds.

Monday (Technique): Record the “Peter Piper” sentence five times. Each time, adjust your microphone’s angle and distance until you get a take with the least amount of plosives in the raw recording. This is your new default mic position.
Wednesday (Surgery): Take your worst “Peter Piper” recording from Monday. Go into Audacity and manually apply the high-pass filter fix to every single plosive. Time yourself. The first time might take 5 minutes. Your goal is to get it down to 60 seconds.
Friday (Sibilance): Record the “Sally sells” sentence. Apply the De-Esser. But this time, experiment with the frequency. Set it to 4000Hz and listen. Then set it to 8000Hz and listen. Train your ear to hear what part of the ‘S’ sound is being affected. Settle on the setting that sounds most natural for your voice.
Sunday (A/B Test): Listen to your final, fully processed recording from this week’s exercises. Compare it to the raw, unprocessed version you started with. That massive improvement is your proof. You are no longer just a creator; you are an engineer. You now have the skill to ensure your voice is always heard clearly, without the distracting, amateur artifacts that hold so many others back.