A stenomask device is a mouthpiece that has a built in microphone that allows a court reporter to speak without any others hearing them speak, it is essentially the “cone of silence” for court reporters.
The stenomask will help to eliminate most background noise, it is useful for voice transcription and allows a court reporter to describe events going on in the court room easily.
Some stenomask devices can be used with speech recognition applications that allow automatic translation to electronic documents, however review is often needed as 100% accurate speech recognition is not always attainable.

A stenomask device looks like this:

Stenomask Device