Why Can I Hear Pokemon Cries?

[The name master]

In the gen 3 games, if I'm walking in a route that pokemon are encountered in, I can occasionally hear a quiet cry of a pokemon encountered in the route. Why?

[MonsterMon64]

One of my favorite touches from Gen 3 tbh. I'm guessing they implemented it to make the routes feel more atmospheric. Worked for me, at least.

They did this with Sun and Moon, too, I believe.

[The name master]

Oh, OK. I thought it had an influence on what pokemon you encounter! Maybe even a way to encounter a shiny easier. Like you listen for the cry, then walk in the grass, encountering that pokemon and you eventually get a shiny if you repeatedly encounter the same species.

I did hear a Rattata cry twice and encountered them (though the third, I encountered a Pidgey instead)

[Captain Jigglypuff]

It's for auditory aesthetics. I believe that cries can also be heard in the DPPT, HGSS, and XY. I'm pretty positive that BW and BW2 did as well but the cries were more subtle.

[wiskyblandi1]

Pokemon is a very fun anime, I like watching.