Allophone

In phonology, an allophone (/ˈæləfoʊn/; from the Greek:ἄλλος, állos, "other" and φωνή, phōnē, "voice, sound") is one of a set of multiple possible spoken sounds (or phones) or signs used to pronounce a single phoneme in a particular language. For example, [pʰ] (as in pin) and [p] (as in spin) are allophones for the phoneme /p/ in the English language. The specific allophone selected in a given situation is often predictable from the phonetic context (such allophones are called positional variants), but sometimes allophones occur in free variation. Replacing a sound by another allophone of the same phoneme will usually not change the meaning of a word, although sometimes the result may sound non-native or even unintelligible. Native speakers of a given language usually perceive one phoneme in that language as a single distinctive sound, and are "both unaware of and even shocked by" the allophone variations used to pronounce single phonemes.