it's nirvana...and , surprise yourselves,kurt wanteed this to be on bleach,but poneman,the guy from sub pop did not allowed it,and he thought kurt was a retard....time bomb,you're version is right,it really does not sounds like nirvana,but it is...and it's not helium,they used some effect,but actually,kurt could do that voice,and he did it live a couple of times
it's nirvana...and , surprise yourselves,kurt wanteed this to be on bleach,but poneman,the guy from sub pop did not allowed it,and he thought kurt was a retard....time bomb,you're version is right,it really does not sounds like nirvana,but it is...and it's not helium,they used some effect,but actually,kurt could do that voice,and he did it live a couple of times