A semi-controversial opinion, but I love a voice note. I love it when my friends and colleagues send me them. But I don’t love it when they send me one without a follow-up line of text explaining what it’s about. Probably, as it is a voice note and not a call or text, it’s in no way urgent. But some sort of nod to its content is always polite. Anything like, “regarding dinner next week; not urgent” or “some background on the new client” will do.