female narrator: Hearing aids have come a long way from the devices your grandparents used, but the idea behind them– amplification– is still considered the best way to treat most types of hearing loss. In their most simple form, hearing aids have four basic components. No matter what style or size of hearing aid you get, all of them will have these four components: microphone, amplifier, speaker, and power supply. Microphones and receivers convert energy from one form to another. The microphone gathers sound and converts it into an electrical signal. Located between the microphone and receiver, the amplifier increases the amplitude of the signal supplied by the microphone before sending it to the receiver. The receiver takes those electrical signals from the amplifier and converts them back into sound. And all this happens in that tiny package that is your hearing aid. The introduction of digital signal processing has revolutionized hearing aids. Scientists and manufacturers have written and developed smart software that have led to benefits like improved speech understanding in noisy environments, increased gain without feedback, enhanced listening comfort and speech perception, the ability to customize settings to match the wearer’s hearing needs, and more precise directional capabilities. All this technology still requires a power source. That’s where batteries come in. The hearing aid industry has standardized battery sizes for hearing aids to make it easy for you to choose the correct size. Each battery type has a corresponding color tab. From smallest to biggest, they are: size 10 with a yellow tab, size 312 with a brown tab, size 13 with an orange tab, and size 675 with a blue tab. Your battery’s life will depend on your hearing aid type and how often you use your hearing aid. Typically, batteries last three to ten days with average use. For more information about how today’s hearing aids work, talk to your hearing healthcare professional.