I agree with Christine and Gloria.
My mom had Taxol and Carboplatin with radiation concurrently. They did the Carbo instead of the Cisplatin because she had hearing aids already, and I guess the Carbo was less likely to damage her hearing (???). The first two weeks, she did pretty well and was just tired. I would say 2 1/2 to 3 weeks, it started to get quite hard and got progressively worse every week with burning, blistering in her mouth and throat/mucositis, painful swallowing, dry mouth. This all continued for a month afterward, and then she gradually healed and improved. She had to discontinue the chemo after 4 weeks because of the effects on her blood, but she tolerated the chemo well otherwise with mainly constipation and nausea from time to time. She did not lose her hair. I did hear the docs say that her reaction to her treatments was one of the worst they'd seen, so please try not to worry that this will be your husband's experience. My mom had an autoimmune disorder, so that may have played a part.
She managed to forgo a PEG tube, but I frequently wonder if she had one, if she would have been better hydrated and nourished and wouldn't have had such an extreme reaction and a tough time, and maybe she could have completed her chemo regimen. I'll be thinking about you guys and hoping the treatment is tolerable for your husband.