Completely-in-the-canal (CIC) hearing aids are the smallest size of hearing aids, practically invisible to an observer. Custom designed to fit the wearer's ear, CIC hearing aids fit deep inside the ear canal and most closely resemble the natural configuration of the ear for a more natural sound.

CIC designates a size of hearing aids, but does not describe the circuit inside the shell. CIC instruments can have conventional, D circuit analog, or digital technology housed within their tiny casing.

CIC hearing aids are meant for people with mild to moderate hearing loss, but in some cases they work very well for people with severe hearing loss. Due to the size, CIC aids may work better for those folks who do not have dexterity problems.

Among the many advantages of CIC aids are:

• CIC instruments are so small they are nearly invisible, which is cosmetically appealing for both men and women.
• CIC hearing aids provide a close placement of the receiver (speaker) to the eardrum, which gives sound a natural boost in loudness.
• The microphone of a CIC instrument sits in your ear canal, simulating natural sound reception.