Built-in microphones tend to do a poor job of isolating sounds which results in background noise that makes the desired sounds difficult to hear, especially for people with hearing impairments.
The AmpRidge MightyMic microphone plugs directly into the headphone jack of any smartphone, tablet, or computer that supports microphone input. It proves an alternative audio output jack so users can still plug in headphones while the microphone is plugged in. Its compact size makes it easy to use in class and makes in relatively discrete. The MightyMic microphone works well with an iPhone and is only slightly longer wider than the width of the phone. The microphone even worked fine with my bulky iPhone case. Once plugged in you can angle the microphone towards the front of the room to capture the most important sounds. In my testing, the MightyMic microphone was on par with the built-in iPhone microphone for close range recording, but worked considerably better than the built-in microphone in a classroom or outdoor long range environment. The MightyMic microphone reduced background noise resulting in better sounding audio playback. If you frequently record classes, lectures, or meetings and are less than satisfied with your device's built-in microphone, the MightyMic mic is a good option to give your sound a boost. If you're looking for a big improvement in sound quality quality you may have to look towards more expensive options.
The Ampridge MightyMic retails for $70 on AmpRidge.com. Also included in a protective carrying pouch and foam protective cover.