As the original poster indicated the sound is heard across multiple systems and various high definition source material, a logical conclusion would be that the sound is present in the original recording.

Having spent some time around both analog and digital audio production, I suggest that what is being heard is likely a purposely added effect called an Exciter (effect). Initially developed in analog form in the 1970's, the process adds very high frequency harmonic distortion and is commonly applied to vocals. Some find the effect enjoyable. Others not.

I owned an (analog) Aphex Exciter back in the day in my home studio and didn't like it much. Like many other analog effects, the equivalent is now commonly available in digital audio workstations as a VST plug-in.

Best regards,
Roger