Subtle whine noise when accelerating

[Adrien]

Hello everyone,

I started noticing a noise coming from the front of the car when accelerating. Since I recently bought the car (used), I am unsure if this is a normal sound or if it indicates a problem.

Here's the link of the audio file: https://drive.google.com/open?id=165...ZEQAHUtFHSNm9V

The noise is mostly noticable between 5 and 8 seconds:


I performed a few tests so far:
- Not influenced by AC
- Sound is louder when accelerating but still present (very faint) when rolling at a constant speed
- Sound pitch and loudness is not affected by the gear I am in (automatic transmission)

Should I be worried or is this a normal sound?