A speech sound which is produced by the opening of the vocal tract, with vibration of the vocal cords but without audible friction is called? Given the previous question, write a context that contains the answer. It can be 1 - 20 sentences. Context:
In Eastern Catalan (except Majorcan), unstressed vowels reduce to three: /a e ɛ/ > [ə]; /o ɔ u/ > [u]; /i/ remains distinct. There are a few instances of unreduced [e], [o] in some words. Alguerese has lowered [ə] to [a].