unique 'coil whine' sound Yoga 2 Pro

Been using the Yoga 2 Pro for almost a month now.

I would like to add that I tend to notice sounds that others may not.

So I came across this unique sound that's similar to a coil whine. The sound is brief like 1 or 2 seconds. I am able to identify that the sound occurs when the AC plug is plugged in but is not charging the battery. The sound occurs when the CPU revs up (I'm guessing over 70% of it's capabilities).

Usually scrolling down on a website filled with pictures (ie Facebook, Instagram) can duplicate this sound. This doesn't occur all the time. I would hear this sound maybe like 2-5 times in an hour depending on what I'm doing.

I'm able to narrow down this also only occurs using Energy Manager in all the modes except Stable mode which leads me to believe that the high power modes (yellow fix- daily, cinema, high), along with the AC adapter plugged in (but not charging) and sudden increase in CPU usage will lead to this coil whine/screech brief sound.

I have tried various methods to eliminate this sound and came across several solutions. Use stable mode but lose out on the yellow fix. Or use Energy Manager modes but limit the Maximum power state (power options) to 68%.

When the AC adapter is plugged in and charging or if laptop is running on battery, this sound will not occur.

I have Energy Manager conservation mode battery on so this occurs when the battery is maxed between 55-60% and not charging anymore. I have yet to try if this sound will occur when the battery is at 100% with AC plugged in and not charging.

This coil whine sound could be a result of voltage change but not sure if this will damage the laptop in the long run so decided to post this in case others may want to know.