That guy, ladies and gentleman, is Mark Cave. Mark is not deaf. 

Mark Cave is a Deaf Services Queensland interpreter, who was born to deaf parents and who grew up with the Australian language for the deaf, Auslan.

He has become a social media sensation and has his own hashtag, #signguy

"I was fortunate enough to have deaf parents, so I was brought up with the language," he says in an interview provided to journalists by Queensland's Emergency Services.

"But then I went and studied and became accredited to become a professional level interpreter," he said.

He says the dramatic facial expressions he uses are part and parcel of Auslan and not "simply making faces."

"It is different to English, it is not based in English, so the facial expressions are not based on English," he said.

"The facial expressions used, the speed, and the way you produce signs are similar to the way you use intonation in spoken languages and how you intensify the language you use or soften the language you use," he explains.

"A lot of people think it's making faces, but it has a syntactic or a grammatical meaning behind it."

If you are lucky enough – or within the right circles – you may have witnessed US President Barack Obama's address at the University of Queensland in November 2014 during G20.

Mark Cave was the interpreter that day.

"That was a really good experience," he said.

Mark Cave works mostly with people with a mental illness.

"What I mostly do is work in mental health, so interpreting for people who are deaf and also have a mental illness."

Does having an interpreter available to deaf people really make a difference in natural disasters?

Mark Cave says deaf people often get information second or third hand and it can be misunderstood.

"To have an interpreter right there – with the Premier – in real time – it means so much to them."