A system for providing voice-to-text captioning service comprising a relay processor that receives voice messages generated by a hearing user during a call, the processor programmed to present the voice messages to a first call assistant, a call assistant device used by the first call assistant to generate call assistant generated text corresponding to the hearing user's voice messages, the processor further programmed to run automated voice-to-text transcription software to generate automated text corresponding to the hearing user's voice messages, use the call assistant generated text, the automated text and the hearing user's voice messages to train the voice-to-text transcription software to more accurately transcribe the hearing user's voice messages to text, determine when the accuracy exceeds an accuracy requirement threshold, during the call and prior to the automated text exceeding the accuracy requirement threshold, transmitting the call assistant generated text to the assisted user's device for display to the assisted user and subsequent to the automated text exceeding the accuracy requirement threshold, transmitting the automated text to the assisted user's device for display to the assisted user.