Direct deposit is a great convenience. It is very dependable. You can sign up by contacting your local Social Security office. But if you don't sign up before your disability hearing then it might be too late to have your back benefits are paid by direct deposit because the Social Security Administration may have already sent out your check for back benefits.
There are a couple of problems with direct deposit of past due benefits. SSA sometimes has people sign up for direct deposit right when they apply for benefits. Sometimes, people forget that they even signed up and they keep looking for a check in the mail when the money has already been deposited to their bank account. Worse yet, sometimes people close the bank account that they told the Social Security Administration they wanted to use for direct deposit. If this were to happen to you, you would find that it will take a while to straighten this out. It might be necessary for you to go to the Social Security office to update the Social Security Administration on your current account information.