Hearing amplifiers are compared by style, durability, battery life, application and quality of sound, states RadioShack. There is also a wide range of prices for hearing amplifiers.
Amplifiers are intended for nonhearing-impaired people who want to improve their hearing at places such as sporting events and concerts, notes RadioShack. The amplifier is not meant to be hidden and comes in three different styles. The first mimics a classic hearing aid and rests behind the ear attached to an earpiece. The second looks like a Bluetooth device and clips to the ear, whereas the third style looks like an MP3 player with a small handheld device connected to a headset or earbuds. A better-quality amplifier usually indicates longer-lasting durability.
Hearing amplifiers come with batteries that may or may not be rechargeable. Rechargeable batteries can often have 15 hours of life from a single charge. As most human speech ranges between 1 and 2,000 hertz, it is advisable to find an amplifier within this range to avoid distortion. Maximum sound should not exceed 140 decibels to avoid causing pain and damage to the ear. The price of hearing amplifiers ranges from $6 to $270 each, as of February 2015.