This a very old bit of kit. It was used 30 years ago to test a patient's hearing. Puts out a noise at various frequencies through headphones. Not sure who would have any use for it (fun biology lessons about hearing perhaps?) but thought I should at least offer it before taking it to the tip! Have tested it and it still works.
Simon
Medical Audiometer (Little Kingshill HP16)
This offer has been gifted to someone and is no longer available.