At his bond hearing on burglary-related charges, Joshua Santuche’s mother stepped in with what she called survival sign language—an inarticulate version of American Sign Language—to allow her deaf son to understand the court proceedings and post bond. Without her help in the courtroom, attorneys said the 21-year-old Santuche would have been lost in a world where no one spoke his language and he could neither hear nor understand them.

Santuche is one of about 50 deaf people incarcerated in Miami-Dade prisons each year, and a new lawsuit filed Thursday in federal court alleges Miami-Dade County Department of Corrections and Rehabilitation systematically violates their rights by failing to provide interpreters.