There are dozens of databases that you can use depending on what aspect of your topic you are focusing on. If you are focusing on the technical aspects of your topic, you can use the computer science/information technology or engineering/technology databases. If you are looking at the legal aspects of your topic, check out the legal databases. If you are looking for more information re: hearing aids and cochlear implants, check out this list of audiology journals. If you are focusing on the history or social aspects, you can use other databases listed below.