Rayovac Proline hearing aid batteries set the standard for the industry. These batteries offer consistent and reliable performance to power today's sophisticated digital circuit hearing aids. When patients complain about their hearing aids not functioning as they did when they first got them, the first thing I want to know is what kind of battery they are using! The list of problems associated with improper batteries is lengthy from reports of static, increased whistling, reduced control of background noise and the main one, poorer speech understanding. Afterall, you got these expensive devices to help you understand speech as well as possible. For your hearing aids to work well, you need batteries that deliver.