Invisible-in-Canal (IIC)

An invisible-in-canal hearing aid is the smallest style of custom hearing device. It sits deep inside the ear canal, beyond the first bend, and is not visible from outside the ear. Because of its position, the IIC takes advantage of the full acoustic properties of the ear canal, which can improve sound localization and produce a more natural sound quality for some wearers.

IIC devices are appropriate for mild to moderate hearing loss. Their small size limits the power they can deliver, and they are generally not suitable for severe or profound hearing loss. Deep placement can cause some users to experience the occlusion effect (a boomy, hollow quality when speaking or chewing) if the device does not fit precisely. IIC hearing aids use very small batteries with shorter battery life. They require more care to insert and remove, so they are not typically recommended for people with dexterity challenges.

IIC devices are custom-made from an impression of the deep portion of the ear canal.