I turned on my PIP and when I switched the audio to the small box, it has a high pitched noise associated with it. The model is a 61" Sony KP61HS10. Wondering if all models do this. Best way to test is to use the same channel for both feeds. Only happens on the cable input. Heres the weird part. My mom and her friend of age 50+ were unable to hear this sound, but both me and my sister early 20's, WERE able to. Can anyone else explain how we are able to hear a different frequency? I am having about 20 people over for a gathering so I'm going to do a test to see if there is a corelation between age and hearing frequencies.