Mishearing the professor

Courtesy of my cousin Dickie, this politically-incorrect joke:

A professor at the Auburn University was giving a lecture on Paranormal Studies. To get a feel for his audience, he asked, “How many people here believe in ghosts?”
About ninety students raised their hand.
“Well, that's a good start. Out of those who believe in ghosts, who believe they have seen a ghost?'
About forty students raised their hand.
“That's really good. I'm really glad you take this seriously. Has anyone here ever talked to a ghost?”
About fifteen students raised their hand.
“Has anyone here ever touched a ghost?”
Three students raised their hands.
“That’s fantastic! Now let me take this question one step further. Has any of you ever made love to a ghost?”
Way in the back, Ahmed raised his hand.
The professor took off his glasses and said “Son, after all the years I've been giving this lecture, no one has ever claimed to have made love to a ghost. You've got to come up here and tell us about your experience.”
The Middle Eastern student replied with a nod and a grin, and ambled his way up to the podium.
When he finally reached the front of the auditorium, the professor asked, “So, Ahmed, tell us what it's like to have sex with a ghost?”
Ahmed replied, "Gee, from way back there, I thought you said goats..."