Sound processing units and effects, such as equalizers, compressors, and reverb units, shape and manipulate audio signals to achieve the desired sound. These units are crucial for both live performances and recording, allowing musicians and engineers to control dynamics, tone, and special effects. Prominent brands include Lexicon (reverb), BOSS (multi-effects), TC Electronic (compressors and EQ), and Universal Audio (preamp and audio interfaces). These processors are used in virtually every genre of music, from studio mixing to live sound, enhancing the auditory experience through creative effects and precise sound shaping.