You could say, "my voice is hoarse because I went to Karaoke last night with my colleagues". Usually, people talk about a boy's voice "breaking" when he reaches puberty.

I’m hoarse because we went out to karaoke after work last night. (Wouldn’t need to say that “your voice is hoarse”. “Colleagues” is rather formal. It would me more typical to convey that from the context) I’m hoarse because I sang karaoke last night. I sound like this because I sang karaoke last night.

Hey there, The most natural sentences that occur to me are: 1. I lost my voice singing at a Karaoke night yesterday. 2. I've lost my voice as I went out for Karaoke last night with my colleagues. ---> ...if you have 'lost your voice' it means if you try to talk almost no sound comes out; it is hard for people to hear what you are saying. 3. My throat hurts because I went out for Karaoke last night with my colleagues. ---> ...if your throat hurts then your voice might sound different, or it might hurt to talk, but people can still hear you clearly. Hope that helps :)