Researchers have developed an experimental device that can non-invasively help quiet tinnitus, or the ringing sounds in ears, by targetting unruly nerve activity in the brain, in just four weeks.

Nearly 15 per cent of people worldwide suffer from tinnitus, a condition which causes phantom sounds such as buzzing and whistling in their ears.The device, as described in the journal Science Translational Medicine, uses precisely timed sounds and weak electrical pulses that activate touch-sensitive nerves, both aimed at steering damaged nerve cells back to normal activity.After four weeks of daily use of the device, the participants reported that loudness of phantom sounds decreased, and their tinnitus-related quality of life improved. 

"The brain, and specifically the region of the brainstem called the dorsal cochlear nucleus, is the root of tinnitus," said lead author Susan Shore, Professor at the University of Michigan."When the main neurons in this region, called fusiform cells, become hyperactive and synchronise with one another, the phantom signal is transmitted into other centers where perception occurs," Shore added."If we can stop these signals, we can stop tinnitus. That is what our approach attempts to do, and we're encouraged by these initial parallel results in animals and humans," she said.The approach, called targetted bimodal auditory-somatosensory stimulation, involves two senses. The device plays a sound into the ears, alternating it with precisely timed, mild electrical pulses delivered to the cheek or neck.

The approach aims to re-set the activity of fusiform cells, which normally help our brains receive and process both sounds and sensations such as touch or vibration, what the scientists call somatosensory inputs.No patient experienced a worsening of symptoms or quality of life, or other adverse events. Some said their phantom sounds got less harsh or piercing, or became easier to ignore."We're definitely encouraged by these results, but we need to optimize the length of treatments, identify which subgroups of patients may benefit most," Shore said.