According to Thorne, the reasons for such sounds and gesture-accompanying expressions entering the language in written form is down to the nature of internet language as a mixed mode form of communication. As the article explains:
We looked at meh on this blog a while back and you might find this link helpful to find out more.
"A lot of internet communication is written speech, or transliterated speech," says Tony Thorne, a language consultant at King's College London. "Social media is all about nudging and poking. It's a more amplified conversation."
Ultimately, finding written ways to express the visual - like shrugging - is a key component of internet communication and social networks, says Mr Thorne. "People introduce these light hearted conversational things which normally you only find in speech," he says.
In that way, he suggests, "hey-ho" could just be the new emoticon.
Elsewhere, The Daily Telegraph tells us that other sounds are appearing as words too, including heh and hmm. And they blame young people (as they often do) as well as the usual suspects: Facebook, Bebo and Twitter.