For anyone with a hearing impairment, a hearing aid is almost a given. However, this free app (currently in beta), developed by researchers at the University of Essex, turns your iPhone (or iPod or iPad) into a hearing aid. Your iOS device already has a microphone and it comes with earphones too — making it the ideal tool. While a cheap hearing aid just amplifies all sound, the app can amplify only those frequencies which the listener has trouble hearing. You don't need a hearing test either — at first start, the setup process helps you choose a pre-set that is appropriate to common types of hearing loss.
