A bassy thump or “explosive” sound heard in a vocal mic (this is called a “plosive”). Pops often occur when the vocalist pronounces words with “p”, “t”, “b”, etc. sounds in them. These consonants can create a puff of air that strikes the microphone diaphragm, creating a thump in the audio signal. In general, windscreens will help with pops to an extent, but a pop filter will be more effective. Be careful that the pop filter you choose is transondent (see WFTD archive), and serves only to break up the plosive’s effects.