It turns out that those who hear voices may be better at listening to you in a noisy bar. At least, that's the finding of a new study led by researchers at Durham University and University College London (UCL).
They discovered that people considered "non-clinical voice-hearers" – those who hear voices but have no mental health issue – can pick out hidden speech amongst jumbled sound much better than those who do not hear voices. In a real-life scenario, this means they would probably be better at holding a conversation at a concert or in a busy, loud bar.
For the study, published in the journal Brain, researchers scanned the brains of participants as they listened to a series of disguised speech sounds called sine-wave speech. Twelve of the people involved experience auditory hallucinations – that is, they hear voices – while the other 17 do not.
In most cases, people can only hear the speech sounds after they've been told to listen for it. But in the experiment, 75 percent of participants with auditory hallucinations detected the speech before even being told it was there. This compares to just under half of those without auditory hallucinations who unscrambled the noise.
The brain scans show that those with auditary hallucinations instantly and automatically responded to the voices hidden in the scrambled noise. The parts of the brain that were active are areas linked to attention and monitoring skills.
"These findings are a demonstration of what we can learn from people who hear voices that are not distressing or problematic," said Dr Ben Alderson-Day, lead author and research fellow from Durham University's Hearing the Voice project, in a statement. "It suggests that the brains of people who hear voices are particularly tuned to meaning in sounds, and shows how unusual experiences might be influenced by people's individual perceptual and cognitive processes."
While many with schizophrenia or bipolar disorder hear voices, it is also thought that between 5 and 15 percent of the general population have heard non-existent voices at some point in their lives. As many as 1 percent may have longer and more complex experiences that could require medical attention.
While no one involved in the study is known to have a mental health condition, it is hoped that in the long term the research will be used to help shape policy and treatments for those suffering from more severe, distressing forms of auditory hallucinations.
"This is a really exciting demonstration of the ways that unusual experiences with voices can be linked to – and may have their basis in – everyday perceptual processes," said Sophie Scott, a professor at the UCL Speech Communication Lab.