1968 Press Photo Bell Telephone Laboratories – RRV65243 Outlet Pay With Paypal

Photo measures 8 x 10 in. Robert Spencer, Bell Telephone Laboratories, checks an electronic tone ringer designed for the hard of hearing. Microphones are mounted on the spinning device in foreground to simulate for Spencer what hard-of-hearing persons hear when the phone equipped with the ringer actually rings.<img src="https://hipe.historicimages.com/images/RRV/RRV65244.jpg"