It's either wear and is clicking when it changes direction or the linkage came loose at the wipers... Open the hood when the blades are wiping .. no doubt the noise is at the bolt connecting the linkage to the wiper assembly
Make sure the blades are the correct size and not so long that they extend past the glass and strike the trim or body. Also the blades need to be in good condition as I have seen worn out blades make noise.
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