Voice over is not working.

I have bought an ipod shuffle 4th generation. For some days it worked fine but after some days the voice over stopped working. The language which is set for my voice over was english UK which is a female voice but after the voice over stopped working the voice changed to a male voice. when I press the voice over button when a song is playing the volume decreases for 2 seconds and again increases. Please help me. I am using windows 8.1 pro operating system and my Itunes version is 11.3.0.54.