Invisible hearing aids are completely-in-canal devices that sit deep within the ear canal, making them virtually undetectable to others. They work best for people with mild to moderate hearing loss who prioritize discretion and have good manual dexterity for handling small devices. These hearing aids aren't suitable for everyone - factors like ear canal size, degree of hearing loss, and desired features affect candidacy. Some users might need to compromise on advanced features like wireless connectivity or rechargeable batteries to achieve the most discreet fit.