The employer is NOT REQUIRED to accommodate you as the employee with the best options available. I kindly asked to have C.A.R.T. service if I ever have an important meeting involving with several people. My boss said no but he did provide me with basic accommodation needed to perform my duty - emails, IM, notes. Many companies commuted via emails/IM nowaday.
Sorry imdeafsowhat... but I don't see anything on your employer's wrongdoing in firing you. I know it sucks but you failed to meet the job's requirement needed to accomplish the task. If you were fired because of your religious affiliation, disability, etc... then yes you do have the case. Best of luck on finding your next job! Suing them is not exactly a great way to start your career.