Mobile devices such as smart phones, tablet computers, and MP3/iPods can be used as hearing assistive technology (HAT). Sound output is possible through the built-in speaker of the devices or
by connecting transducers, including earphones, earbuds, or telecoils. The actual devices, when used with
appropriate apps, can enhance or modify the incoming sound or convert
it to a visual signal. This article discusses the implications for current technology and use, but also discusses what some of the current issues are related to the technology and the need for further research and improvement.