There are three types of digital hearing aids to select from:  Behind-the-ear aids sit behind the ear and are connected to a mold within the canal.  While common, they have been made less necessary due to advanced digital hearing aids like the in-the-ear types.  These aids are more popular, and have the luxury of fitting inside the ear to offer a more discreet look.  Another type – in-the-canal – is even smaller, and fits visibly in the canal, but not as noticeably.  Finally, completely-in-the-canal aids are more hidden in the canal, and harder to adjust than other hearing aids.