basic units of sound in a language are called
Phoneme A phoneme (/ˈfoʊniːm/) is one of the units of sound (or gesture in the case of sign languages, see chereme) that distinguish one word from another in a particular language. For example, in most dialects of English, the sound patterns /θɪn/ (thin) and /dɪn/ (din) are two separate words distinguished by the substitution of one phoneme, /θ/, for another phoneme, /d/. (Two words like this that differ in meaning through a contrast of a single phoneme form what is called a minimal pair). In many other languages these would be interpreted as exactly the same set of phonemes (i.e. /θ/ and /d/ would be considered the same).
Speed of sound The speed of sound is the distance travelled per unit time by a sound wave as it propagates through an elastic medium. In dry air at 0 °C (32 °F), the speed of sound is 331.2 metres per second (1,087 ft/s; 1,192 km/h; 741 mph; 644 kn). At 20 °C (68 °F), the speed of sound is 343 metres per second (1,125 ft/s; 1,235 km/h; 767 mph; 667 kn), or a kilometre in 2.91 s or a mile in 4.69 s.