This article summarizes the phonology (the sound system, or in more general terms, the pronunciation) of Standard Chinese (Standard Mandarin). Standard Chinese is based on the Beijing dialect of Mandarin. Actual production varies widely among speakers, as they inadvertently introduce elements of their native dialects (although television and radio announcers are chosen for their pronunciation accuracy and standard accent). Elements of the sound system include not only the segments – the vowels and consonants of the language – but also the tones that are applied to each syllable. Standard Chinese has four main tones, in addition to a neutral tone used on weak syllables.