if i don't have field work, then i'm by my pc so it would be 6-9 hrs at work, 2-3 at home, and i always have a something on when i sleep
if i have field work (2 days a week on avg) then it would be 2-3 at home and while sleeping
on average 7-8 maybe
oh, and i have my headphones on while walking/skateboarding/biking !