Have you noticed that some pokemon have the same cry?

EXACT MATCHES
Rhyhorn + Charizard
Goldeen + Caterpie
Venusaur + Dragonite
Machop + Omanyte (though Omanyte's first part is higher pitched)
Poliwag + Ditto
Kadabra + Alakazam
Diglett + Doduo
Vileplume + Aerodactyl
Slowbro + Machamp (though Slowbro's first part is lower pitched)
Igglybuff + Chikorita

SOME KIND OF CLOSE
Grovyle + Sharpedo
Steelix + Typhlosion
Ekans + Magikarp
Golem + Koffing
Barboach + Whiscash
Metagross + Rampardos
Tangela + Weezing
Kadabra + Alakazam
Staryu + Starmie (Starmie gets extended though)
Kyogre + Dialga

SO CLOSE, BUT YET SO FAR
Regirock + Registeel
Snorunt + Regice
Glalie + Flygon
Palkia + Heatran
Lugia + Giratina


P.S.: This is just going on Pokemon I've seen in my Pokedex, so.... I'll update when necessary...


<EDITED>

Uh, yeah, a lot of people have noticed. Oh, and 2 of the Regis(Don't know which ones) have the same cry.

you forgot geodude, zubat, and arcanine sound REALLY close

Back in the RBY days, video game cartridges could'nt hold nearly as much information for many things, among them the sound. Because they couldnt make new cries for every pokemon, Game Freak decided to use cries multiple tiems for different pokemon. Later, when GSC was released, the games could hold much more info, so the need to multi-task the aounds was eliminated. I'm pretty sure there are a couple of pokes that have cries that diifer only in pitch, and those are all very similar to each other (silcoon, castcoon, for excaple), but those are the only ones

Yeah I've noticed. And:

Venusaur + Dragonite
Kadabra + Alakazam
Golem + Koffing
Barboach + Whiscash

Those are nowhere near close. Alakazam and Whiscash are just extended cries of the pre-evos. (And KOL and Ghett0, you're both wrong too...)
blaziken234 got it pretty much covered. It is rather fun to hear similar cries, although it's not that important of an issue...

- DNA

and {mewtwo]'s cries are similar too, but at different pitch.

Actually, they do differ.(No, not in pitch)