1) Barium esophagography
2) Ambulatory 24-hour pharyngoesophageal pH monitoring
3) A biopsy of the larynx which may show laryngitis.
Since you are not responding to the medications; Nissen fundoplication surgery may be needed. Following specialists are needed to work in tandem for treatment;
1) ENT specialist
3) Speech therapist, and
Following measures are helpful, meanwhile, surgery is planned (you may be doing many out of them):
1) Small 5-6 meals a day.
2) Last meal should be eaten 3 hours before lying down.
3) Avoid; fried or fatty foods, chocolate, peppermint, alcohol, coffee, carbonated beverages, citrus fruits or juices, tomato sauce, ketchup, mustard, vinegar.
4) Eat slowly so air is not swallowed.
5) Swallowing therapy by a speech-language pathologist.
6) Lose weight if obese or overweight.
7) Elevate the head of the bed by 6 inches.
8) Avoid tight clothing.
9) Stop smoking, if you do.
I would be happy to assist you further, if you need any more information.