These letters are a little old. We do not use these letters in writing generally, but that hats on the letters make the pronunciation thin. I can give you an example; there is a word "kar" in turkish and it has 2 different meanings. 1) snow ; hava çok soğuk, kar yağıyor. (pronunciation is kar) 2) profit ; şirketimiz bu yıl çok kar etti. (pronunciation is kâr) In turkish you can write these word without hat on the letter. (If you want to use hat on the letter it is still correct) But you should pronounce them differently.

hâlâ and hala are diferent words also these kind of word rooted from arabic or persion also these two letter are ع is â and ا is a

You try to use this dictionary, http://www.tdk.gov.tr/