Question Odd oscillating noise from bottom of PC

[Andvbk]

I have a custom pre-built PC from June of 2018, starting yesterday an odd oscillating high pitched noise started coming from the bottom of my PC, in the lower compartment of the case where my 2TB Seagate Barracuda HDD and my Seasonic Focus Plus 650W Gold PSU is located. Around June of this year I finally upgraded to an M.2 SSD, which is my new boot drive leaving the old HDD unused, it is partitioned but is not actively storing anything, and is still connected and activated.

I can only notice the sound when my head is turned a certain way and it seems like the sound is originating from the lower of the PC. To me, it doesn't sound like anything I've been able to find online for examples of coil whine, failing HDD, etc, so my hope is someone could help identify the sound.

Hear is my full spec list in case anyone recognizes the sound that may be common to another component:

PSU: Seasonic Focus+ 650W Gold
GPU: Evga GTX 1070Ti SC
CPU: Core i7-8700K 6-Core 3.7 Ghz
Motherboard: MSI Z370 PC Pro
RAM: Ripjaws V 2666 Mhz 16GB (2x8)
HDD: Seagate Barracuda 2TB
Cooling: Cryorig H7

My only upgrade since 2018 is a Samsung 970 Evo Plus 500 gig M.2 nvme drive (June/July 2021), everything else has gone untouched.

Here is the sound, note that I placed my phone right below the PC so the noise is significantly louder than just a foot or two away

https://imgur.com/a/1U1I2YV

View: https://imgur.com/a/1U1I2YV


I greatly appreciate any help anyone could provide, thank you for your time.

 

[Andvbk]

I've noticed that my computer won't actually play the sound from the link due to the pitch being too high, only the background audio. It does play on my iPhone Xs, though.