Finding audio signal time delay cross-correlation vs. impulse response?

1. How do you find the delay between two signals?
2. What is the difference between impulse response and frequency response?

How do you find the delay between two signals?

τdelay=argmax ((f∗g)(t)), this will estimate the time offset where the signals are best aligned.

What is the difference between impulse response and frequency response?

The impulse response is the response of a system to a single pulse of infinitely small duration and unit energy (a Dirac pulse). The frequency response shows how much each frequency is attenuated or amplified by the system. The frequency response of a system is the impulse response transformed to the frequency domain.