Hearing aids are rated according to criteria such as features, comfort and functionality, says Consumer Reports. Collecting and comparing information from user surveys and evaluating various aspects of performance is an effective method for rating the various styles and brands of hearing aids available.
Factors to consider in rating hearing aids include battery life, earwax buildup, background noise cancellation, ease of adjustment and the amount of amplification provided, according to Consumer Reports. Larger aids have batteries that last longer, while smaller units may be difficult for some people to adjust and do not include directional microphones that cancel peripheral noises. Smaller hearing-aid units are typically good for mild to moderate hearing loss.
Modern hearing aids come in a wide variety of sizes and differ in how they're placed in the ear and how effective they are, notes Mayo Clinic. The smallest and least visible are molded to fit completely in the ear canal and improve mild to moderate hearing loss. Aids that fit partly in the ear canal are also designed for mild to moderate hearing loss and offer features not available on the smallest designs. Full-shell and half-shell devices provide improved hearing for people with mild to severe hearing loss and include directional microphones and volume control. Units that fit behind the ear are connected by a tube or a wire to an earpiece that fits in the ear canal; these aids assist with all types of hearing loss.