YOU SAID:

this is the first I've heard of it

INTO JAPANESE

これは、私はそれを聞いた最初

BACK INTO ENGLISH

I heard that this is the first

INTO JAPANESE

これは、初めて聞いた

BACK INTO ENGLISH

I first heard this,

INTO JAPANESE

私は最初、これを聞いた

BACK INTO ENGLISH

I first heard this

INTO JAPANESE

私が最初にこれを聞いた

BACK INTO ENGLISH

I first heard it

INTO JAPANESE

最初それを聞いた

BACK INTO ENGLISH

I first heard it