And yet, the Qur'an itself says otherwise.
I, a non-Muslim, will now actually QUOTE this book that you keep talking about but never actually cite. Yusuf-Ali translation (because I've always liked it best).
*****
6. Inna alla
theena kafaroo saw
aon AAalayhim aan
thartahum am lam tun
thirhum l
a yu/minoon
a
6. As to those who reject Faith,
It is the same to them
Whether thou warn them
Or do not warn them;
They will not believe.
7. Khatama All
ahu AAal
a quloobihim waAAal
a samAAihim waAAal
a ab
sarihim ghish
awatun walahum AAa
thabun AAa
theem
un
7. God hath set a seal
On their hearts and on their hearing,
And on their eyes is a veil;
Great is the penalty they (incur).
****
So, by the Qur'an's
own admission, Allah is responsible for "sealing our hearts and hearing."
And this isn't exactly far into the text. This is Chapter Freaking TWO.