I have a Transcend Sata external harddrive its 450GB, and its just gone on a year.
I use it to watch movies and store them.
Now, recently when im watching a movie it will get stuck for a few seconds (Usually 5-10) and the hardrive makes a high pitched sound. I think that it may be getting longer. Ive scanned for viruses and there were none.
Ok. Whether it's a really cheap RAID controller, i've had one and it did the same thing to my drives connected to it, or in your case an external hard drive, the same thing will happen when the controller fails; the controller turns your drive(s) on/off creating the high pitched sound as they do.
You should be able to get into the external drive to reveal a standard internal drive, PATA or SATA.
Remove it and install it inside your computer and connect it to your motherboard.