Buzzing/cracking static through headphones when Internet is connected connected

Question

Issue:

• When my headphones are connected to my workplace laptop there is some persistent buzzing and crackling static type noise that comes through.
• This stops when the Ethernet cable is unplugged.
• It also stops when the volume is dropped to zero, although it isn’t sensitive to what the volume is when it’s non-zero.
• I can’t hear the noise coming through the laptop speakers when the headphones are unplugged (although I’m in a noisy environment so it's possible it's still there and I just can’t hear it).
• The noise does seem to fluctuate when sometimes my browser (Chrome) loads new webpages.
• Other sound plays fine, including streaming music.
• It seems highly affected by transfers across the network too. So it’s more likely a network thing than just the Internet.

Computer details:

• Dell Latitude E5470
• Windows 7 Professional
• Intel Core i7-6820HQ CPU @ 2.70Ghz
• 64-bit

Headphones:

• Audio-Technica ATH-M50x

How can I fix this and remove the noise?

I haven’t found similar questions on this site helpful for my issue so far, and none have the specific Internet-related crackling I’m experiencing.

Solution

The problem has been solved by plugging my headphones into the jack in my laptop dock rather than the laptop itself.

The noises also stopped when using lower quality headphones, so may be due to some noise from some internal components being amplified by my (decent quality) headphones, which I've seen suggested on other sites/answers. It's possible the noise loses signal/gets filtered out by the time it reaches the jack in the laptop dock, which could be why I'm not hearing it from that source.

Comments

[conor]

I've tried both a different Ethernet cable and tried disconnecting the power. The issue persists in both cases once the network connection is established. Unfortunately I only have access to one wall port and need to be on this network (this is at my workplace). It seems I can't do much about the other suggestions. Anything else I cold try?

[Christopher DeMarco]

Even if a different wall jack won't let you get on the network, it'll still have different electrical characteristics which might not demonstrate the problem.

[Christopher DeMarco]

Also try a different pair of headphones, or a pair of powered speakers, plugged into the jack.

[conor]

I ended up trying a different pair of (lower quality) headphones and didn't hear the noise, so suspect it may be related to answers I've read about good headphones amplifying things you wouldn't normally notice. My laptop is on a dock, which it turns out has a headphone jack. Using that jack fixes the issue with my headphones.