BPH, Pattaya International etc do have Hearing Departments, the equipment they use however for testing is rather old.
You must insist before any testing you want a full print out and not pay until provided. (I should warn you the print outs are very amateur!)
The shop on the Sukhumvit have little to no testing equipment and I quote "She uses her experience to set them up?"
Once it is agreed you want / need a hearing aid then certain manufacturers come down from Bangkok, Phonak etc. (Even for BPH etc)
However I can with certainty inform you that