The vocoder is the development of Lucas Wolenczak, which allows the real-time translation of clicks, whistles and other vocalizations of dolphins into human speech, as well as the reverse. Nathan Bridger is first introduced to this technology upon boarding seaQuest DSV 4600 in 2018, when he happens upon the fact that Darwin was brought aboard without his permission.
Bridger previously attempted to create such a device, ultimately abandoning it for hand-signals, a point of jocularity for Wolenczak during his first meeting with Bridger (DSV: "To Be or Not to Be").
The vocoder has a portable, wireless hand-held interface that can be used to interface with the vocoder technology, with vocoder instrumentation located at the moon pool and at the bridge dolphin dome (DSV: "To Be or Not to Be").
It is a classified technology and is not known to the general public, as The Regulator is unaware of it and abducts Darwin in an attempt to secure proof for his theories, after hearing Darwin "talk" during a reprogramming session (following heat damage to the vocoder's system) while engaging his "pursuit" of Verne throughout seaQuest (DSV: "The Regulator").
The vocoder allows seaQuest's crew to understand the intentions, and communicate to, an alien simulacrum encountered in a spaceship buried for millennia under the ocean floor. The vocoder is used to encode an invitation to the aliens and beamed to M-100, unbeknownst to the United Earth/Oceans Organization (DSV: "Such Great Patience"). When the aliens respond to the message, Darwin is brought to a UEO facility, which also houses a version of the vocoder (DSV: "The Fear That Follows").
The technology is included in seaQuest DSV 4600-II and operates in much the same way as the system aboard its predecessor. Despite the reduction of the ship's scientific status in lieu of the events in 2032, the vocoder is still in use after Captain Oliver Hudson assumes command, although he refuses to talk to the dolphin (2032: "Brave New World", "In the Company of Ice and Profit", "Smoke on the Water").