Everything with a microphone is 3 pole.
These days, Apple devices are 8-pin 2-lane lightning, and use separate lanes for audio and control. The Apple EarPods appear to be 7-pole: separate grounds for each signal wire, all as twisted pair. That's pretty cool, as someone who wants earbuds to work well near RFI.
This is the first time I've heard that argument, what RFI are you near that was breaking normal headphones?
Mobile phones. The good old br t br t brrr tt br whenever the mobile phone thinks it has low signal and fires at full power and causes interference.
A video demonstrating it: https://www.youtube.com/watch?v=8TWXCVbBTcc
Specifically, that sound is associated with TDMA-style networks (e.g. 2G GSM), since the transmitter has to rapidly switch on/off, giving other phones a chance to transmit. This induces a series of audible-frequency voltage spikes in nearby cables.
CDMA-style networks (e.g. CdmaOne, 3G GSM, LTE) don't have that problem, since the transmitter is effectively always on while transmitting.
That's why you don't notice that sound very often anymore.
3G used a 10 ms allocation unit, but with HSPA it's been reduced to 2 ms to become more "TDM-like" (it turns out that in real life code superposition is not so good, better split in time and do less superposition: less interference, less power consumption, better results).
I honestly don't know the source of the 2G noise, but from the above it's not as simple as TDM vs. no TDM, as current 3G and LTE both in practice have a time-based allocation component on roughly similar granularity as 2G. One difference could be the transmission power: 2G can go up to 2W, while LTE is 200 mW maximum so 10 times less. I don't have 3G peak Tx power in mind, but in practice I guess it should be closer to LTE than 2G (interference minimization in a same frequency / reuse 1 network: both LTE and CDMA are reuse 1 deployment, while 2G is not). That will certainly cause a 2G device to have higher power spikes. And I guess the details of the transmit pattern are likely to play a role too.
Except yesterday. And today. And every second day in my life. Because even my Nexus 5X in a 4G network occasionally sends/receives SMS in GSM mode.
Edit: thanks to sibling comment for explaining.
These are unbalanced mics. I've never seen balanced mics outside of recording studios.