Sounds will be more expansive...
couldn't resist.
All things remaining the same, you'll get a small difference in the reflections but if your listening position is the same as in the 8ft ceiling house, the sound of you tapping your feet and humming along to the music will drown out any small difference in timing you get. Now if the room volume increased then there will be a difference but I bet you wont be able to tell much...
One of the experts may chime in here and give you a better estimate.
I forgot: Congrats on the new house!
Alonzo
Gameroom:>Mainline to HD820, SR45 to Pipette
>BeePree Kaiju & SII to Altec 19 knockoffs
Office:>BH Stat amp to Koss 95x, T20 SET to JBL 4309s
Den:> MorePlay 845 SET to Altec Valencia's