>>14800950Gamefreak wanted every pokemon to sound as unique as they looked, but due to hardware constraints with the Gameboy speakers and memory they couldn't just emulate the range of animal sounds out there. So they developed a series of harmonic melodies that people could easily distinguish from each other. It was neat to be able to recognize a pokemon not only by the way it looked, but the way it sounded in the game, and not only that but you could also listen to how your pokemon changed as they evolved. It was a very neat trick to give many pokemon a "feeling" that was unique to them.
It used to be a thoroughly preserved tradition but around the 5th gen and maybe halfway from 4th gen Gamefreak decided to drop the synthesized cry "feeling" for more of a mixed audio sample feeling. Cries were less of a "noise that represents that pokemon" and more of an actual sound the pokemon could make.
I find it a very distasteful and uncreative change to be honest. Many of the older cries were sounding outdated when compared to some of Black and White's straight up mixed animal sounds, but I never felt it was a problem until they started making cries like this. They revamped not only the gen I cries but any cry pre gen V to sound less unnatural in an attempt to homogenize every cry, which shows me that it's a direction they're not interested in preserving anymore.
Trust me I'm a pokemon cry PhD.