Whither your tablet microphone is not working at all or it makes you sound as if your from another alien planet. The best solution is to go with an external microphone.
Here are some choices for your tablet they work on all Apple, Android, Sony, and other manufactures.
Below I show you how to install the external microphones, for both wired and the more popular wireless and Bluetooth models.
Samson Go Mic Compact USB Microphone - Plug n' Play
This microphone is great for any Tablet, it's an external mic that is small but can be used from high quality recording or Talking. Comes with a handy clip to easily attach and un-attach to your tablet.
Edutige EIM-003 i-Microphone Music Edition for iPhone / iPad / iPod / Droid Voice Recorder
This small but highly sensitive tablet mic plugs right into your mic port on your tablet.