I hear audio coming at of my computer but not out of my monitor how to I solve i

here is a quick spec....
http://h18000.www1.hp.com/products/quickspecs/11485_na/11485_na.html

because you use a workstation it have the on board Audio connect to a inside speaker...

In the quick spec it say it also have "Sound Blaster Audigy 2 ZS PCI card"

You need a Audio cable connect from the "Sound Out" on System to Audio In in the LCD..

You monitor seems didn't come with the Audio Cable
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00655637&tmp_task=useCategory&cc=us&dlc=en&lc=en&product=459838