One of the subsystems is the phonological loop (PL). It deals with auditory information (i.e. coding is acoustic) and preserves the order in which the information arrives.
The PL is subdivided into:
⚫ The phonological store, which stores the words you hear.
⚫ The articulatoryprocess, which allows maintenance rehearsal (repeating sounds or words in a 'loop' to keep them in working memory while they are needed).
The capacity of this 'loop' is believed to be two seconds' worth of what you can say.