Secrets behind human speech

Prof Scott shows poet James Wilkes how 'speech jamming' works

It's an unusual performance.
As James Wilkes reads aloud one of his poems, he slurs, stutters and stammers, struggling to get the words out.It's a far cry from his usually fluent readings of the material he knows so well.But today, James is taking part in an experiment at University College London's Speech Communication Lab.As he reads, his voice is played back to him through headphones just a fraction of a second later. And it is remarkably disruptive.

He says: "It's a very, very odd experience.

"It's like you are not saying words you have just said, so you are waiting for them to come.

"The concentration involved is huge."

Two cultures 
The writer has just taken up a poet-in-residence role at the Institute of Cognitive Neuroscience where the speech lab is based. He is hoping to get a creative insight into the science behind speech.

"Everyone speaks, but it is something that is also really complex and strange," he explains.

 "The work they are doing at the lab is shedding some kind of light on that complexity and strangeness. And as a poet I really want to be part of that."

The experiment that James has just taken part in is called Delayed Auditory Feedback (DAF), which is also known as speech jamming. Professor Sophie Scott, who heads the research group, says that it's a simple test that is helping to identify the mechanisms of speech. She explains: "What this is telling us is that when we speak, we make a noise, and if we fiddle around with that noise, it can make speech production difficult. "So it is telling us something interesting about how we use the sound of our own voice to guide speech output."



Brain waves
How we produce - and perceive - speech is the focus of research at the lab.Professor Scott says: "Speech is incredibly complex. "In fact, as a sound, speech or the human voice talking is comfortably the most complex sound you encounter on a day-to-day basis."

She explains that just by hearing a few words, you start to build up an image of what a person might be like.

"Our voices convey an awful lot of information about us, whether we want them to or not," she says.

"If you couldn't see me, but hear me, you'd probably have a good guess at my sex, my age, where I come from, aspects of my mood and my socio-economic status - all of this is expressed in my voice.