If you're working with audio, simply press . on your numeric keypad to do an audio preview.
You shouldn't work with audio in AE. It is terrible at working with audio. That's more for Audition or, at the very least, Premiere Pro.
That being said, let's try to fix your problem:
What version of your OS are you running?
What are your computer specs?
What is the full version number of your CC 2014 installation? Is it 126.96.36.199?
Could we see a screenshot of your memory and multiprocessing preferences?
In the project window, I see mp4 video, windows media video, and an mp3 audio file. You aren't doing yourself any favors by using them in AE. I would transcode the video to quicktime movies in the Photo JPEG codec, and the audio to either wav or aiff files. By doing so, AE does a lot less computation just to make pictures and sound. That's a good thing.
....after you answer Szalam's questions, of course.
I run i7 4710HQ
16 Gb RAM
VIdeo - GTX 860M 2GB
version of AE 188.8.131.52
about multiprocessing i had it on and off and was the same thing.
Well used like that all the time in AE 5.5 and AE 6.0 and never had any issues whatsoever. In CC this is a nightmare , i even converted .mp3 to .wav and still same issues. Freezing up. Can anyone from Adobe actually tell me what is going on and how to fix this issue ????!!!!
I've not had issues with those formats in CC. Try using CS6 to do your current project and see if it behaves properly.
Can anyone from Adobe actually tell me what is going on and how to fix this issue ????!!!!
If you want help from Adobe, contact Adobe support. This is just a user-to-user forum and not an official way to get help from Adobe.