Chipmunks generally only make one sound repeated at fast intervals, in long strings (they used to say you could estimate the temperature by counting their calls per minute and doing some math.)
On AllAboutBirds, the yb cuckoo recording has quite a variety of vocalizations which do not all sound the same, and some sound quite different from a chippie.
I suspect you may have heard chippies if you heard 5 different places giving off the same monosyllable but repeated over and over. That sounds like chips calling territory.
Maybe you could record the calls (by taking video without a subject) for later replay at home to compare? And/or start looking for a chirking chipmunk. They are often at near ground level when they call territory, on a stump, fallen log, or rock. They tend to stay still on it calling steadily over and over. If you find one and video it, you may get it fixed in your mind sooner as its call?
I've never heard a cuckoo, but I grew up with chippies, so I don't really know how to describe their chirk. It's something you get used to, like a cardinal, after prolongued exposure. Since chips are pretty common even in the city, maybe you could find a park nearby to just listen for a few days to them?
There are some decent recordings of chipmunks, doing both their chip call and their chirk call at miracleofnature.org/blog/the-chipping-munk
if that's of any help.
