If you are matter-of-fact, you talk about something in a plain, calm way, as if it were nothing special — even when the thing itself is exciting, terrible, or sad. A doctor says 'The leg is broken' in the same tone she would use to say 'It is Tuesday'. That is matter-of-fact. It describes the person, the voice, or the words: a matter-of-fact voice, a matter-of-fact tone, a matter-of-fact way of speaking. It goes in front of a noun most of the time ('in a matter-of-fact voice'), but it can also come after 'be' ('She was very matter-of-fact about it'). Note that we usually say matter-of-fact ABOUT something. Two things worth knowing, though. First, the feeling is not always missing — often the person feels a lot but keeps it off the surface, and English speakers hear that. Saying 'He was matter-of-fact about his father's death' can quietly mean he was holding himself together. Second, it is usually neutral or even a small compliment (calm, not dramatic, no fuss), but with the right tone it can be a small complaint — cold, uncaring. The context tells you which. There is an older, drier use too, meaning 'sticking only to facts, with no imagination', as in 'a matter-of-fact report'; you will meet it in writing more than in speech. Careful: the phrase 'as a matter of fact' (no hyphens) is a different thing altogether — it means 'actually' and is used to correct or add something.