An improved cochlear implant and method of stimulating are disclosed. For detipping, mechanical energy is stored when the tip is mounted to the nozzle and is released when the tip is to be removed to facilitate removal thereof. When application data for received messages does not match stored message, the message can be stored to a buffer. The piston is retained within the housing by the cooperative engagement between the spring urging the piston out of the first end and the head of the bolt in abutment with the second end. The multilayer optical film exhibits low absorptivity and can reflect light approaching at shallow angles as well as normal to the film.