ST2010 Monitor Has No Sound?

I bought a Dell ST2010 monitor in Feb.from Staples  when the monitor on my HP computer kept going to sleep & finally went totally black. I used the Dell monitor until the replacement HP monitor arrived. After only 5 months, the replacement HP monitor did the same thing as the first one & became totally useless. I am now using the Dell monitor again.  I just realized that I have no audio on this monitor. I tried to find info online & it's confusing. One forum post says the monitor has no audio but a description of this monitor on Dell website says it does. I tried to get help from Support but when Dell scanned my monitor to get the serial no. they said it was purchased in another country. It was purchased at Staples in ME.Can someone tell me - does this monitor have audio capability or not? If not, can I add that option. The Quick Installation sheet was not in the box w/the monitor. I do have an unidentified cord that came w/the monitor.