Starkey Axio 4 hearing aid has 4 channel capacity, 4 band sound processing system, 65dB gain, 00-105dB fitting range, ISO compression, feedback cancellation system, noise control, automatic telephone response, environmental adaption, automatic directionality, programmable rocker switch, surface nano shield, battery door lock, hydra shield protection, programmable telecoil, voice indicators and up to 4 programmable memories.