Austin asked:

I live in an apartment building, and in the building across from mine, there is always a yappy dog barking the backyard. Today it was barking for more than 3 hours straight early in the morning. I do not know anyone in the other building, but I can hear the dog clearly through my window. Are there devices that emit a high-frequency sound and makes dogs be quiet? My neighbor across the floor also has a dog who barks whenever the neighbor leaves. Hopefully this solution can deal with both.

Yes there are devices that emit a high frequency sound. Ypu can buy them from Amazon or your local pet store.