Was Rayleigh correct?

Lord Rayleigh is credited for developing the "duplex theory" for sound localization, which states that the brain relies heavily on ITDs for low frequency sounds, and on ILDs for high frequency sounds.

Final Question: In your own words, do the results you have obtained in this practical agree with the duplex theory?

This concludes this practical.

(Note that this practical varied ILDs or ITDs independently, one at a time. In nature, they do of course tend to vary together, so that sounds that are louder in the left also tend to arrive earlier at the left. So how does the brian put ITDs and ILDs together? If you are curious you can explore this on the next page.)