Learn Italian: Senti questo rumore? - Do you hear this noise?

Senti comes from the regular -ire verb sentire (to hear). To make the "you" (singular) form, you drop the -ire ending and add -i. So, (tu) senti means "you hear".

Where is the word for "do" or "you" in this sentence?

In Italian, you don't need a helper word like "do" to ask a question; you just change your tone of voice to make it a question. Also, the word for "you" (tu) is left out because the -i ending on senti already makes it perfectly clear who is hearing the noise.

Wait, doesn't ascoltare mean "to hear"? Why use sentire?

They are similar but distinct! Ascoltare means "to listen" (paying attention on purpose, like listening to music), while sentire means "to hear" (a sound just coming to your ears). Here, you are asking if the person passively perceives a noise, so sentire is the correct choice.

Rumore ends in -e. How do we know to use questo instead of questa?