Activates high-speed brainwaves, which reflect how alert people are Faster brainwaves are often reduced in people suffering from Alzheimer's Previous research found flashing lights may be a promising treatment Yet, noise could be a more effective, 'entirely doable form of therapy' One in eight over 65s in the US have Alzheimer's; a common form of dementia  By Alexandra Thompson Health Reporter For Mailonline Listening to low-pitched noise, such