Echo time delay determines which frequency components get filtered out

Evidence

A 10-millisecond delay would correspond to a notch filter removing 50, 150, 250, … Hz components, just as it did in our discussion leading up the explanation of the pitch of an overhead jet aircraft. Many repetitions, as expected coming from perhaps dozens of trees, could lead to quite deep notches, but of course the trees would not have been perfectly uniform sound reflectors. — Eric J. Heller, Why You Hear What You Hear- An…, 2653