Yes you can and there are a number of apps in the App Store that you should search yourself to see which may best suit your needs, if you are after a dictaphone facility. Some suggested in this forum are Evertone, QuickVoice and Dragon Go! suggested by a few members. But many more are on show for your choice.
The iPad itself has an inbuilt voice activated typing facility. Swipe the Home Page to the right and tap the microphone symbol to have your voice turn into text. It's surprisingly accurate. Manual corrections may be necessary. For an excellent well-researched article on using keywords, punctuation marks etc in dictation, search a post by twerpoet "Dictation Tips and Tricks.
The Forum search area is very useful in having your questions answered
Regards, Andrew