Has anyone ever come across a Stammering Treatment Oscillator?

Built probably in the 60's or early 70's this item has found it's way into the possession of the owner of the website Dustygizmos and he's trying to figure out how it works and who made it.
Rather than as he was lead to believe, I don't think the device delivered any shock, rather may have been a masking or auditory blocking generator.
EMS (Greenham) have been approached and deny having had any connection with its manufacture and I am wondering if the device has been made in a hospital electronics department, maybe Electro Medical Services department or similar. The standard of construction is not up to commercial standards so maybe a laboratory prototype. I think the "PB" connector might refer to Patient Button with the "Phones" suggesting headphones being used either by the patient or maybe technician to monitor the reaction.

If anyone recognises this or the logo, or knows someone who may have used it I'd be interested to know and share the knowledge with Mr Maybury.

Many thanks in advance, oh and the website does bring back some nostalgia for those long lost days of electronic simplicity!

Attached Images
oscillator.jpg cct board.jpg logo.jpg
Last edited by BBottomley; 27/10/17 5:59 PM. Reason: image uploaded

**** Still grumbling in the Pennines ****