The "dbx voice effects" likely refers to the dbx 286s, a channel strip processor that combines a mic preamp with several integrated audio effects to achieve a louder, more professional vocal sound in real time. The key voice effects are: a Compressor to even out volume, a De-Esser to reduce harsh "s" sounds, an Enhancer to add clarity and definition to low and high frequencies, and an Expander/Gate to reduce background noise