Jonathan Frakes is actually able to play the trombone and has done so since the age of nine. However, the producers wanted a more professional sound, so they hired session musicians to overdub his playing. No effort was made to match the overdub to the visual image, and as a result it often looks as though the actor has no idea what he's doing. This would be repeated throughout the series nearly every time Riker plays.
The computer voice informing various decks of which transporters to travel to is that of Michael Dorn.
Jonathan Frakes noted this episode was, to him, one of the highlights of the first season. "A fabulous show. Those were the kind of chances we took first season that when they worked, they worked great. It was a very chancy show and I loved it. Those characters, the Bynars, why haven't they returned? That was a very well-conceived idea. They should have them as a regular on the ship to fix the engines or whatever the hell they do."
This episode won an Emmy Award in 1988 in the category Outstanding Sound Editing for a Series.
The Bynars themselves were played by young women. Children were considered for the parts, but the production team thought that it would be too problematic because of the limited time they could work each day and the need to hire teachers. Each actress was required to wear extensive make-up, which was created by make-up supervisor Michael Westmore. A large single-piece bald cap was made from the same mold for each actress, which required some customized trimming to get it to fit properly. To cover up problems with the seams of the cap, some fake hair was added on the Bynars' necks. Each actress also controlled the flashing light inside the apparatus on the side of the headpiece through a battery pack attached to the waistband of their costumes. To disguise their voices, the pitch was lowered in post production. It was originally planned to add subtitles over the Bynars' conversations between themselves.
Jack Sheldon: famous character actor, cartoon voice actor, and jazz musician appears as the piano player in the Holodeck.