Among the world’s languages, humans can produce over a hundred unique sounds for communication. This excludes burps and grunts or other non-specific articulations, but does include the “click” sounds found in some African languages (see Zulu). English utilizes only about 39 of these sound units (24 consonants, 15 vowels). Most speakers (of all languages) are not conciously aware of the sounds they can and do produce, and of course individual variation does exist. All children are born with the capability of learning any language, but by the age of five years or so, will have become attuned to the sounds of their native language, and slowly lose the ability to easily distinguish foreign sounds.