The gears are not moving when the car is in park, therefore, no noise from the trans.. it is coming from somewhere else. quite possibly, it's the starter motor is continuing to spin. have someone listen under the hood while starting. if it is the starter, the noise will be more prominent when listening from under the hood. how long does the noise last?

Mcdevito75 here, Not really directly with the transmission itself, no. The loud whinning you hear at start up could be the transmissions Torque converter, however I'm thinking toward the serpentine belt or other drive belt,s on the engine, specially if none of the drive belts, Alternator, A/C compressor, Power steering Belts Haven"t been changed in 2 years, Have your Local repair shop take a look for you.