A Year In Language, Day 342: Rotokas
Rotokas is one of the many languages of Papua New Guinea, belonging to the small North Bougainville family, named for Bougainville Island. There are 4-5000 speakers.
Rotokas is generally considered to have the smallest phonetic inventory of any language. The standard dialect has only six consonants: /p/, /t/, /k/, /b/, /d/, and /g/. In addition to its small size, the lack of contrasting nasal consonants (like /m/ or /n/) is particularly unusual. The Aita dialect does have nasals, which brings the count to 9; still smaller than any other language. It's worth nothing that Rotokas, like most small inventory languages, has considerable amount of allophonic variation, i.e. consonants can sound different depending on the environment. All languages have allophones, for example in American English "t" sounds typically become more like a "ch" before "r", as in "tree" or "try". In Rotokas the sound /d/ can also be pronounced as /n/ or /l/, though to the Rotokas ear they are the same.
As one may expect, Rotokas also has the smallest alphabet, using only 12 letters of the standard Latin: A, E, G, I, K, O, P, R, S, T, U, and V. Ironically this small alphabet is still more letters than are strictly speaking necessary: S and T represent the same sound (/t/), but S is used before the letter I and, uniquely, in the word "Rotokas" itself.