I wondered the same. This quora comment says about 6 seconds: https://www.quora.com/What-is-the-signal-delay-to-the-ISS https://www.quora.com/What-is-the-signal

I wondered the same. This quora comment says about 6 seconds: https://www.quora.com/What-is-the-signal-delay-to-the-ISS https://www.quora.com/What-is-the-signal-delay-to-the-ISS