The "secret ALJ" policy implemented in late 2011 has come to an end. For the past year and a half or so, the particular administrative law judge (ALJ) assigned to your disability case was not disclosed prior to the day of the hearing. It was a terrible policy, and now the policy has changed.
Ask the name of the judge assigned to your hearing, and the hearing office staff will tell you. Starting the weekend of April 20th, the assigned ALJs will be listed on ARS, the SSA's online service for representatives. After that weekend, hearing notices will include the name of the administrative law judge assigned to the claim.