What could be causing this high pitch noise?

I've got a high pitch noise that occurs with my throttle response in my '96 Ford Thunderbird V8. When I hit the gas, I hear this whistle; so if I hit the throttle with a tap-tap-tap, I'll get three whistles that are ever so responsive to me tapping the throttle. It REALLY shrieked similarly, when backed my car up a good 30-40 ft. the other day on a dead street to read a sign that I had to take a second look at. So, that tells me it could be coming from my transmission; at least that noise and the first one I mentioned which happens only in drive, with my throttle; from the fuel line, alt. voltage or a bearing from a pulley/pump pulley from under the hood. I just put in a brand new water pump and serp. pulley kit less than a month ago; could it be the new water pump? It only made this noise mainly on the highway before, but was happening even louder on the expressway the other day. Seems like it's getting worse unless it's just the water pump breaking in. Thanks for your help!