Source of two sounds

I don't really know how to explain the sounds but I've heard it in many anime and I've been searching all over the internet, trying to figure out what makes those sounds. I thought at first one of it would be from those Yaki-imo trucks that go around but I guess I'm wrong.

One of the sounds is played in the anime Nichijou at 21:43 minutes and the other in Shirokuma Cafe at 16:44 minutes.

This is probably a weird question...but I really really want to know.

Thanks for any help..

Hi. Could you kindly be more specific about which videos or at least episodes you are referring to when you say "21:43 minutes" and "16:44 minutes"?

Assuming you are referring to episode 1 of Nichijo where a birds-eye view of a town is featured, it's just some background music of the show that's probably supposed to imply loneliness that tends to strike us at sunset hours. If there is anything cultural about it, it does sound a little bit like a tofu vendor that used to come around before sunset with his little horn until supermarkets started to dominate the country. The following video is just for reference.
https://www.youtube.com/watch?v=o6T0qGFG2Ss

I couldn't find the 16:44 one.

Wow, Uco, thank you so much! That's exactly the sound I was looking for. I've heard that sound in many different anime and even games. There was one game app on the Apple Store called Showa Candy Shop in which it would play every once in a while and every other anime I heard it in were located in non-city areas so I thought it would be something like that but I just couldn't figure it out.

As for the other one, I didn't know we could send links..
https://ww5.gogoanime.io/polar-bear-cafe-episode-3

That's the episode. After exactly 16 minutes and 44 seconds, when the anteater says he wants to eat Ramen, that sound plays. I have also heard this sound many times.

But I am really greatful for the previous information. Thanks again!

Well, technically speaking, you may be violating the law if you paste a link that is obviously illegal. In that case, you can get away with it by just mentioning the title and scene hoping that someone owning legal footage can search it for you ;)

So far, I couldn't find any anteaters in the video you suggested (I didn't exactly download the video, so it was hard to search). But since you say ramen, maybe the sound you're looking for is this:
https://www.youtube.com/watch?v=X7HBTnMBaVA

Oops. I should have thought of that... OTL

Thank you so much for all the effort. And you're right, that is the sound. Really, thanks for being so awesome and helpful. I feel so relieved now that I finally know what they are!