There’s Something About Sibilance

We identify sibilance in the Intro class, though mostly focus on other things.  And while I have a Sibilance-Fix module for Audio ER, it’s tough to shoehorn anything more into what is already a pretty information-dense class.  Sibilance also doesn’t necessarily affect everyone, nor does it have precisely the same solution. Sibilance is, in short, a slightly sticky set of circumstances.
So, let me ask you: If you recorded that last sentence, would it sound like several sets of snakes in a basket?
If so, meet your friend, Sibilance.
It probably makes some significant sense to specify what sibilance means.  Though thought of as a “hissy S”, it actually can show up on other consonant syllables such as “T” and “Z”.  You know it when you hear it – in recordings or over room monitor speakers. In that case, it usually sounds like a burst of white noise – exploding during words such as sassafras.
But it’s important to realize precisely what what we are talking about for vocal sibilance.  First, it is not the same as a Daffy Duck’s interdental lisp (where the “s” sound gets replaced by “th”).  It’s also not, strictly speaking, “white noise” as the characteristic tonal harshness of sibilance appears in a very specific area of the frequency range. (Remember, white noise is random waveforms throughout the full frequency spectrum.)
The offending frequencies of a hissy-ess tend to live in the 5kHz to 8kHz range. Everyone is a bit different, but that’s a likely place to find it. As with everything in the booth, getting it right at the source can save a lot of headache later on.  And you are likely to be the source.

Getting it Right At the Source (GIRATS)

When you create a fricative consonant (I’ll pause for a moment while you say that in your best Daffy Duck voice), your airway tends to drastically constrict. Your teeth, tongue and palette work to create that sound, typically by tightening. Speaking precisely can intensify that aspect of your sound. In fact, you can probably create a really cool jet engine sound effect in a very similar manner.
Learning to relax your lips and tongue as you form “S” sounds can lessen sibilance. Extra tension is not your friend here. Using a little less air (as long as it doesn’t affect volume) can also help. Tightening an “S” and adding air pressure until you actually whistle will help find the muscles we are talking about. Once you’ve identified them, then you can start working to control them.
three-curves-freq-responseMicrophone type and placement are the second thing to consider. Your microphone may tend to respond more to that frequency spectrum. If you have a tendency towards sibilance, be aware of the microphone’s frequency response when mic shopping. For example, the bottom two microphones shown in the response chart would intensify any signal in the upper frequency ranges, while the top one has a “flatter” response, neither increasing nor decreasing any signal across the frequency range.
Finally, any microphone will benefit by tweaking the angle and axis rotation. Sibilance issues can often be solved by physical placement of the mic. If your speech pattern tends to form sibilant events, then you should know the mic position and distance which solves that issue in your setup.
Controlling your physical instrument and optimizing mic placement should take care of most of the issues. However, if something slips through the cracks and ends up in your audio, there are software (and hardware) tools which can fix it. Specific “De-Essers” find the offending frequency and then limit that sound when it occurs – those of you who have taken Audio ER may recognize this as a type of Compression. In fact, it is. A De-Esser is really just a compressor which is triggered by a specific frequency.
But I think it’s a mistake to simply slap a De-Esser in place rather than work to gain better control of your instrument.  Relying on the automatic fix puts the burden on the engineer during any recording session, and may undermine client confidence. That could tend to raise tensions, making things worse.  Taking the time now to play around with minimizing your sibilance will pay off when the meter is running.

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