Audio pull up/down. Is it necessary to have external clocking?

Hello experts,

Is it mandatory to have an external clock source in order to work with audio pulls?

If Nuendo is internally clocked and I setup a -0.1% pull down in Project Setup, does this perform the audio pulldown, does it change audio speed?

or does it only affect the visual time display?

Thank you!

When you set pull up/down in project , in fact it’s change TC and Video speed , the audio speed is no change .