High Quality Content by WIKIPEDIA articles! The voiceless bilabial plosive is a type of consonantal sound used in many spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is p, and the equivalent X-SAMPA symbol is p. The voiceless bilabial plosive in English is spelled with 'p', as in pit or speed. [p] is missing from about 10% of languages that have a [b]. (See voiced velar plosive for another such gap.) This is an areal feature of the "circum-Saharan zone" (Africa north of the equator, including the Arabian peninsula). It is not known how old this areal feature is, and whether it might be a recent phenomenon due to Arabic as a prestige language (Arabic lost its /p/ in prehistoric times), or whether Arabic was itself affected by a more ancient areal pattern. It is found in other areas as well; for example, in Europe, Proto-Celtic and Old Basque are both reconstructed as having [b] but no [p].