Beasy wrote: ...I could hear a really high pitched whining noise, sometimes in the distance and sometimes really close. Nobody else in my group of 3 could hear anything at all...
Beasy,
I've seen several explanations on here, but to be honest this is a perfectly explainable and completely non-paranormal event. What you've experienced is a high frequency audio tone in the 18khz to 24khz range. This is a very special range of tones. Why? Because its in a range which is audible to animals and kids, and even younger adults. But for the most part most older individuals lose the ability to hear that frequency range.
Standard wear and tear on the ear, as well as a loss in elasticity of the ear drum, or even damage to the cilia which are the sound receptors in the ear can prevent those tones from being heard.
This is so common of an event that there has been a fad for kids to downlaod special ring tones in that frequency range and put them on their phones so that they can hear it but their parents can not. Unfortunately for them there are some adults who can hear it as well. I'm one of the lucky ones who dispite continued exposure to lound sounds as a young adult (was in a rock band) I can still hear those very high pitch tones. I drive my boss nuts sometimes because I can hear hard drives going bad when he can't hear a thing.
The source of the sound can be many. For one photographic flashes often make high pitched sounds in that range as they recharge for the next flash. This is caused by an internal oscillator connected to a transformer to charge up a capacitor in the flash unit. Alternately, older style TV's also have much the same mechanism. They have a high frequency oscillator which feeds something called a flyback transformer which sends 45,000 vots to the picture tube. This process also ends up squealing at a very high frequency.
Nothing paranormal about it. And absolutely nothing to worry about. As a matter of fact you should be glad. Because it means out of the 4 of you, you have the best hearing left. So be glad!