Microphone - Hearing Aid for Android

Microphone - Hearing Aid is a very simple and transparent microphone app. Is can serve you for testing your device's microphone and speaker, you can use it as external mic or as a megaphone.

You can easily switch between different input/output modes to use it on AUX or bluetooth external devices. Unfortunately, all input/output combinations are currently not possible on Android. You can also tune the sound by using the equalizer.