When recording a song on her laptop, Sarah noticed a slight delay in what she could hear on her headphone and what she was recording at that time. What is this delay called? The delay that Sarah noticed in the playback of her recording in her headphone is called

latency

Explanation:

We could have latency if we want to record with a computer, and then we try to hear that record with the headphone.

This is an audio card's characteristic, this is a time between the input, in this case, Sarah recording, and the output Sarah's headphone.

The computer needs time to process the signal, and for that there is latency, but this depends on more of the operative system and the CPU in your computer than the audio card.