system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do we sing in key when our voices sound different in our heads?

So I know that our own voices sound different to us because they resonate differently to our ears then to someone elses, but how does this affect singing?  My voice sounds a lot deeper in my head so when I listen to a recording of talking I sound higher, so when I sing along wouldn't I be singing in a higher key then I think I am?
  
TL DR; How can singers sing to music when they are singing to a key they hear in the head, which might be slightly different from the actual sound they are producing?
gpt
Your head isn't thick enough to have an effect on the frequency that you hear.  When you listen to a recording of your own voice, what's missing is the deeper harmonics that result from the sound travelling through you skull to the bones in your ear, but it doesn't really affect the accuracy with which you can judge the pitch of your voice.