Tires: front end noise

Question
I have a 1991 Olds Cutlass Supreme. It had newer tires on front when I bought it. I put new struts on the rear and new matching tires on the rear. I know it needs a 4 wheel alignment. It pulls to the left a little and did so before the new struts and tires. I didn't notice it at first but now, I hear a noise when I slow down from highway speeds and when going 35mph in town. It sounds like I have mud tires on it. The pitch of the noise goes up and down with the speed. Can it be so out of alignment that it makes a noise like that? The tires still look good. I thought it might be the tranny, power steering pump or something but all that checks out good. Thanks.

Answer
Mind if I call you by your first name, Mr. Knife?  Good!

Now, Pocket, let me see if I have this right.

You got the car with an alignment problem.  You got new tires for the rears only, but didn't fix the alignment problem.

If that is right, then it is possible the front tires have gotten an irregular wear pattern due to the alignment.  It isn't the alignment that is causing the noise - it's the alignment has caused a wear pattern that is causing noise.  Fixing the alignment will NOT fix the problem.  You have to replace the front tires to fix the noise generation - and if you want to prevent the problem from returning, you also have to fix the alignment.

So if all this is correct, then do this test:  Swap the tires front to rear and the noise should sound like it is coming from the rear, instead of the front.  If so, then you know what to do.  If not, then post back and we'll talk some more.