Using 2N2222 to generate noise - how would I make frequency lower / change frequency?
EDIT: This all is unimportant. The questioner found the error by himself. See the comment. The 47nF capacitor in series with the 2200 ohm resistor kills all bass. 

It's not white noise if you filter it. I bet your system oscillates and you cant stand the high pitched whistle. Why do I think so: I can't see any big capacitor at the 741's supply voltage input terminals. Connect one 50uF 10V to 25V between the same points where the wires from the battery come to the opamp.

The noise, if it is white, can sound quite high pitched and fizzy if you have a little speaker that has no bass and gives enormous boosts to some frequencies. Actually the white noise should have absolutely no pitch ( distinquishable frequency).

If you need a less treble content sound, attenuate some high frequencies (and kill the whiteness at the same time) Connect a little capacitor parallel with the 1MOhm resistor Start tests with 150 pF (that 1MOhm which is connected over the opamp).