[fastball]

Slightly tangential: it looks like some of the sounds your units make in Age of Empires II when you direct them are apparently just phonetic sounds. Specifically in the bottom two sections ("Other symbols" and "Affricates"), a number of those sounds appear to be the exact "words" your units will use on occasion. I thought they were actual words but apparently they're just letters / phonetic units (not really sure what the term for this is)!

[jdmichal]

The word would be "phones" -- distinct units of sound regardless of meaning.

The next level up would be "phonemes", which must contrast against other phonemes within a particular language. For instance, in English /b/ and /v/ are phonemes, because "bat" and "vat" are two different words with only that portion changing. (This is known as a minimal pair.) However, in Spanish, /b/ and /β/ are not separate phonemes; they are two phones in complementary distribution.

[fastball]

Great explanation, thank you!