NO audio on macbook air 2010
A drop is a drop - 1 foot or 10 feet - you dropped it.  

More than likely, you broke something on the I/O Board



This goes for around $70 on Amazon.  I just purchased one to fix a friends 2012 MBA and it was super easy to fix.  You just have to remove the back cover and one screw holds this board in place.  It removes pretty easily.