A treatment program will use neuromodulators to "prime" people's brains to be more responsive to training that may reduce their perception of tinnitus – a sensation of noise in the ears that has no external cause. "We're trying to provide the means for the auditory system to ignore tinnitus," explains lead researcher Dr Grant Searchfield, Head of Audiology at the University of Auckland.
"When people experience tinnitus they become attuned to hearing it in preference to other auditory stimuli – it's a magnet for attention. To break the cycle they need to be trained to attend to other things."
The trial will use people's sense of vision and touch to achieve this.
"In the past it was assumed that tinnitus was primarily an auditory phenomenon, but it has become clear that tinnitus is caused by a much more distributed network within the brain that can be influenced by a number of senses," said Dr Searchfield. "We know that the senses can work for or against each other. For instance if a tactile (touch) stimulus is paired with an auditory stimulus it can make the perceived sound stronger, whereas if they don't match up then the perceived sound is weaker. Visual stimuli can also trick us into hearing sounds that aren't there."
Participants will use computer-based training developed at the university that uses visual and touch feedback to train the brain to ignore tinnitus. A sound-only version of the training has already been shown to produce significant improvements in tinnitus within one month, a much shorter period than the 12 to 18 months required for standard treatments
To further boost the effect, neuromodulatory drugs will be used to make people's brains more responsive to training.
"It's analogous to using performance enhancing drugs in athletics," said Dr Searchfield. "Doing the training can reduce tinnitus but if you use these medications then the training may be more effective or you could get to the end result faster.”
The study builds on previous work at the Centre for Brain Research on how to prime the brain to be more responsive to rehabilitation for stroke or lazy eye. It is a multidisciplinary project involving experts in audiology, medicine, behavioral medicine, pharmacology, vision science, and sport and exercise science.
"We are extremely grateful for the generous philanthropy that supports our world-class researchers. I am confident that the tinnitus research project will eventually improve the lives of those who currently suffer this annoying hearing problem," said Professor John Fraser, Dean of the Faculty of Medical and Health Sciences at The University of Auckland.
Around 20 percent of people experience tinnitus that annoys them and one to two percent have clinically significant tinnitus.