I don't have any perfect tests for you, but perhaps I can help you target your search a little.
First of all, what is your goal in testing these students? Do you want to find out where their strengths and weaknesses lie? If so, then probably the best thing to do would be to get a speech/language sample and a writing sample, then analyse the samples. Also, give them a few passages to read/listen to with comprehension questions following. If their English is primarily written, as is common for Deaf ESL learners, then just cut out the speech sample and the listening comprehension.
On the other hand, maybe figuring out where their strengths and weaknesses lie is not what you need at this moment. Maybe you just want to prove that they need intensive instruction. In that case, consider using a standardized test. Keep in mind that there are very few standardized tests that are normed on a hearing impaired population, and if not normed on the population you are testing, they are invalid...
Feel free to email me if you want to talk about ways to analyse the speech/language samples, etc.
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