In the canal
An in-the-canal (ITC) hearing aid is custom molded and fits partly in the ear canal. This style can improve mild to moderate hearing loss in adults.

in-the-canal hearing aid:

Is less visible in the ear than larger styles

Includes features that won’t fit on completely-in-the-canal aids, but may be difficult to adjust due to its small size

Is susceptible to earwax clogging the speaker