Prosound has a great article on In the Studio: Tips for Controlling Vocal Sibilance. If you’re unaware of what “sibilance” is, very quickly it is the strong consonants that are stressed (sometimes overly so) in recordings. If you’ve ever listened to someone who let’s their S’s linger a little longer than usual, that could be a problem of sibilance in a recording. This lovely article focuses on how to set up your recording area to cut back on sibilance, and what tips you could use to de-esser them.