Invisible-In-The-Canal (IIC) hearing aids go even further to stay out of sight—literally.
Like Canal-style hearing aids, these tiny instruments are custom made to fit inside your ear canal. However, IIC devices sit beyond the second bend of the canal. Because they're deeper in the ear, they're not at all apparent; IIC devices typically come in shades to mimic the shadows of the ear.
A telecoil is designed for telephone use. It prevents feedback (whistling sound) that typically occurs when the hearing aid microphone is covered (e.g. when the telephone headset is placed over the hearing aid).
A directional microphone is built into the hearing aid and helps emphasize sounds coming from in front of the hearing aid and de - emphasize sounds coming from behind the hearing aid. Since most conversations occurs with the listener facing the speaker, the assumption is that the speech will be coming from in front of the hearing aid and noise will be coming from behind the hearing aid.
The memory button allows the user to change between the listening programs that the hearing care professional has programmed into the hearing aid.
The on/off switch allows the user to turn the hearing aid on or off without having to close or open the battery door on the hearing aid.
The Volume control (available on select models) allows the user to adjust volume of the aid manually to fit the listening environemnt