What sibilance is
Sibilance is the harsh, hissy edge on S, T and CH sounds. It happens because those consonants carry a burst of high-frequency energy, and a sensitive microphone placed directly in the path of your mouth picks up that burst louder than it actually sounds in the room.
What plosives are
Plosives are the low thump on P and B sounds: a sudden puff of air hitting the microphone's diaphragm directly, rather than the sound of the letter itself. It reads as a dull thud rather than speech, and it's one of the fastest ways to make an otherwise clean recording sound amateur.
Your microphone choice plays a part
Condenser mics are great in that they pick up more detail, but they're also more prone to harsher sounds precisely because of all that extra detail. Dynamic microphones round the sound out a bit more and give you more leeway with harshness, and for modern podcasts they're what we'd recommend. The Shure SM7B is the industry standard premium option; anything more expensive than that is selling you a pipedream.
Fixing both at the source
- Angle the mic slightly off-axis, a little to the side of directly in front of your mouth, so plosive air bursts miss the capsule instead of hitting it square on.
- Use a pop filter or foam windscreen. Pop filters are cheap and worth every penny, stopping most plosive thump before it ever reaches the diaphragm.
- Back off slightly on distance if sibilance persists, since a few extra centimetres reduces both problems together.
Fixing them after the fact
A de-esser targets the specific frequency band sibilance lives in and pulls it down only when it spikes, leaving the rest of the voice untouched. We recommend the Waves De-esser; while many Waves plugins are a bit style over substance, their de-esser is surprisingly effective, and if you want a real premium option, the FabFilter one is excellent too. Plosives are usually fixed by hand, cutting or fading the thump on the waveform, since they're too short and too variable for an automated tool to catch reliably. Both are easy to overdo: push a de-esser too hard and every S sound goes soft and lispy; the fix should be inaudible on its own.
Prevention beats correction
Neither problem is hard to avoid at the recording stage, and both are harder to fully undo afterwards than most people expect. A few minutes adjusting mic angle and adding a pop filter saves considerably more time than chasing plosives out in an editor later.
Optivox handles the de-essing automatically
If you'd rather not buy a plugin at all, Optivox's processing pass takes care of sibilance for you, along with noise cleanup and mastering, so a recording that got away from you still comes back clean. The mic-technique fixes above are still the most reliable way to stop these problems happening in the first place.
If you're preparing long-form narration, Optivox can handle the broader cleanup and audiobook mastering pass after you've dealt with any severe recording issues.