Carl Icahn doesn't use Twitter very often, but his tweets sure do pack a punch.
The activist investor took to social networking Tuesday morning to express his support for a board of directors change at Nuance Communications.
Earlier this year, Icahn said he had taken a piece of Nuance and actually has become the company's biggest shareholder with a 16.9 percent stake.
He was widely expected to seek a shakeup in the board, and Tuesday brought news that he has begun to achieve his goals.
(Read more: Shares jump on Icahn's energy company tweet)
Subsequent to his approval in the new members, Nuance shares jumped about 2.5 percent. Icahn has been on Twitter since June 20 but has posted just 39 times.
Icahn pointed out that David Schechter and Brett Icahn—Carl's son—had success at Hansa Trust that he hopes to see replicated at Nuance.
Icahn had similar impact Monday in boosting shares of Talisman Energy, where he also has taken a stake.
—By CNBC's Jeff Cox. Follow him on Twitter @JeffCoxCNBCcom.