I think the implication is that Jason is such a geek that he can hear the hyphen (or lack thereof) in the way she says it.
http://www.gocomics.com/doonesbury/2009/11/11/
They redid the colors for some reason; weird.
I think the implication is that Jason is such a geek that he can hear the hyphen (or lack thereof) in the way she says it.