From hearing aids to smartphones

A growing number of "smart hearing apps" that leverage smartphone technology have become available in the iOS app store with prices, ranging from free to about $3.99.  Many apps also have been developed for the Android operating system, ranging from free to about $10.

These apps use the phone's processor and microphone to enhance sound quality while regulating external noise. The resulting sound is then sent back through the earphones, essentially acting as a conventional hearing aid.

The popularity of smartphones and the availability of mobile apps may drastically change the hearing aid market. Some device developers are now developing Bluetooth-enabled devices that can turn a hearing aid into a cellular hub. And some companies are even talking with wireless carriers to incorporate smart hearing apps as a way to provide a personalized voice over Internet protocol (VOIP) for the hearing impaired.