I have read the material from the Picower Institute ( an MIT affiliate. They are researching 40 hz light and sound with a company called Cognitos Thearapeutics.
It seems promising, but still being researched.
As a result, we are using the AlzLife software on an iPad Pro( has to be a Pro to achieve true 40 hz light). Also have to use headphones to achieve 40 hz sound. Our feeling is that it is non invasive, so why not try it - nothing to lose! Hope this helps.