Why do some shops or town centers switch my headphones mode

[jarlrmai]

Okay so a fun one for me

I own a pair of Anker Q30 Bluetooth Noise Cancelling headphones

These head phones have a touch sensitive panel on the right speaker, touching it briefly changes the mode between transparency and noise cancelling (or "normal" if you have NC off) modes, when this happens you hear the voice telling you in the headphones and the sound changes noticeably.

Every so often I have occasion to walk through town and I have noticed that passing certain shops switches modes, I walk a lot with them on out in the country and this never happens and it happened two times walking past the same area of town, down pedestrian only thoroughfares with shops on each side.

My theory is some emitter in the shop is causing the touch sensor to register, but what and why?

 

[Trailblazer]

Can those headphones switch on noise cancelling automatically in response to background noise, or do you have to touch the sensor to turn it on? Is it possible that some kind of sound frequency you can't hear is triggering it?

Looks like that might be the case?

If your Anker Soundcore Life Q30 switches modes unexpectedly, follow these steps to resolve the issue:

First, make sure the headphones aren't programmed to automatically adjust modes based on ambient noise.

Open the Soundcore app on your mobile, go to the noise cancellation options, and turn off any "Auto Mode Switching" or similar functions that may be activated.

Or... I found this thread on Reddit mentioning the same model of headphones apparently having the same problem due to interference from a laptop. Numerous people in the comments say that they get the same thing at certain points on city streets etc. Perhaps something to do with wireless base stations?


Source: https://www.reddit.com/r/anker/comments/148ije0/i_just_got_my_hands_on_a_soundcore_q30s_and_i/

 

[jarlrmai]

My experience mirrors the people on that Reddit post.

 

[Dave51c]

My theory is some emitter in the shop is causing the touch sensor to register, but what and why?

Sounds like a good theory. If the touch sensor is capacitive there could, theoretically, be a resonance with the input circuitry at some radio frequency that has not been accounted for in the design. Have a look around where the shops are for antennas which might be commercial cellular boosters, WiFi base station links or CCTV remote transmitters etc - hard to say what exactly but I'd guess something in the high MHz to GHz region. The shops might have some sort of 'radar' type security systems at street level and these should be low power.

Is it repeatable each time you visit that area? Suggesting steady radio carrier or you were in the right place at the right time for a pulsed system (with potentially more RF energy per pulse).

 

[jarlrmai]

I've never had time to repeat the experiment and I don't walk there often but the 1st 2 times I noticed it was in the same position on the same street

 

[JMartJr]

I'm curious if the change would always be in the same direction (say, turning noise cancelling ON if it had been OFF) or does it change from whichever you happen to be in to the other?

 

[NorCal Dave]

First, make sure the headphones aren't programmed to automatically adjust modes based on ambient noise.

I suppose I've just become a cranky old fart, especially with technology, but the amount of helping type features and nanny settings in nearly everything is annoying as hell. I'm perfectly capable of switching my headphone settings myself, thank you. Our towns roads have been torn up since the big fire 7 years ago, still lots of areas with no lines or markings and lots of small roads that never had any markings. Drives the car crazy, constantly beeping and warning me about how I'm going to drive off the road and die. In extreme cases it'll even slam on the breaks.

 

[JMartJr]

Isuppose I've just become a cranky old fart, especially with technology, but the amount of helping type features and nanny settings in nearly everything is annoying as hell.

I would not mind as much if they were opt-in, or failing that easy and intuitively obvious to opt-out! However...

 

[GM4AJK]

The world is full of RF emitters, but if it's happening as you walk past shop fronts, the likely culprit is the RFID emitters/receivers designed to catch shoplifters. Those need to generate enough energy to power the RFID tag and produce an RF burst of information. In fact they have to do it for a lot of them (imagine taking your weekly shop out of Tesco's, it scans every item with a tag!

So, something to try an experiment with, going in and out of various shops. Especially supermarkets where they are limited to the entry/exit.

Or buy a Flipper Zero and go nuts

 

[FatPhil]

Can those headphones switch on noise cancelling automatically in response to background noise, or do you have to touch the sensor to turn it on? Is it possible that some kind of sound frequency you can't hear is triggering it?

The bose ones I've encountered didn't flip modes because of the contact of the touch, they flipped because of the sound of the touch (so that someone could tap you anywhere and get your attention). Perhaps that (mis-?)feature is still an active one in ones with tactile sensors.

Regarding shops emitting "inaudible" sounds, mosquito is hardly new. Knocks have a 1/n (odd) frequency profile (the hard edge is a square wave), as do scratches (a sawtooth wave), so perhaps the logic is just "unusually large high frequency components => turn off cancellation" and mosquito satisfies that. It would be a terrible design, but tech companies have released things with terrible designs before.