Someone could be tracking you through your headphones | Hacker News Reader

Someone could be tracking you through your headphones

nrkbeta.no

65 pointsingve58 comments

Not sure there's anything new or unknown with this. Just Google "Bluetooth Proximity Marketing" to see the types of technology stores are using to track customers when they walk in....

I don't think that many stores track customers and that a lot of the hype from a couple of years ago never ended up in a successful commercialization of the technology.

(Full disclosure: Author of linked article.)

Yeah, I got excited when I read "bluetooth proximity marketing" because I was hoping that with a few weekends I could start tricking stores into thinking that everyone I ever bump into just walked into the store with me.

However, google returns a bunch of results talking about the stores sending the customer data. And not the other way around. Also the customer needs a specific app.

It doesn't sound like anyone is tracking anyone via bluetooth. At the very least, if they are, then "bluetooth proximity marketing" is the wrong keyword to search for.

I think something similar but very different: not many stores mention it, not much news about it, hardly anybody aware of it.

Even companies that provide it talk on their websites about what they'll give you, the data and tooling, not how they'll take it from your customers.

(It's also hard to talk about without sounding tin-foil hat... I don't mean to. I'm mostly resigned to it, the state of advertising etc., I mean I'll block it digitally of course, but I'm not going to go shopping in a balaclava with exaggeratedly not-mine gait or anything, just still dislike that that would be necessary if one did care enough, if you see what I mean.)

I agree this is stuff which is common knowledge amongst those of us who know a bit about tech. I think the following quote [0] is probably the novel value of the project : "What is interesting about the dataset is that the best example for location tracking of movements are not vehicles, smartphones or even activity trackers – but headsets that do not have MAC randomization, which may make it easier to track the movements of an individual headset rather than the individual’s smartphone."

[0] https://www.hegnes.tech/2021/09/01/location-tracking-of-wifi...

"Everybody already knows about this, you have no reason to be upset" is a common industry refrain when people get caught doing something they know there is a public outcry against.

Whether or not you know about a given thing is irrelevant, it's not a contest.

A lot of people don't, and articles to explain it to them are a good thing.

Things like this are really invasive, and not appropriate – just because they've been happening for a while doesn't make it more OK, it's just means they've been getting away with it.

Bose 700 NC have a horrid app, terrible mic, frustrating noise cancelling (NC), and all the tracking too. The Sony equivalent experienced the same issues.

I've repaired two pairs of Bose QC25 (wired only) to the point where they no longer have NC, but eventually had to retire them. The NC is very poor relative to modern models.

A modern wired-only NC headphone would find a niche but receptive market.

Edit: Not to mention the only way to use is through the app.

Maybe I'm just old, but I really like the simplicity of wired headphones. No pairing nonsense, and no tracking (at least from the headphones).

No lag, no charging, compatible with almost every device that makes noise on a regular basis. Not compatible with recent iOS devices, any Cisco iOS devices, about a years worth of higher end Androids, one flavor of Nintendo GameBoy advance (GBA SP, I think), and some Speak & Spells (modern ones don't have a jack, but some of the antiques do).

Add a small portable DAC/amplifier and you get every benefit of wired plus superior sound quality. With one I started randomly telling apart new notes and passages from individual instruments in songs I heard tons of times before. This is with Ikko Zerda, picked up because it’s what was in stock, most likely this device isn’t special and anything is an improvement over built-in jack. (Lossless music and inexpensive SE215.)

Meanwhile, most popular audio codecs that work over BT cap bitrate, making lossless truly useless; most headsets and phones don’t support LDAC, and if you get a lucky combination that does music will likely stutter if you’re anywhere close to a busy area of the city or if your phone is in the wrong pocket.

(Where some wireless headsets do win is state of the art active noise cancellation, -30 dB when you’re in a really noisy place without an option to use IEMs or earplugs can be a bliss.)

As "Technologist" I hate that we are so quick to dismiss solid, reliable technology in favour of the latest and greatest.

> Where some wireless headsets do win is state of the art active noise cancellation

Also audio amplification apps provide hearing aid features on even basic TWS earphones while a typical hearing aid can be very expensive.

I was tracking this need on my validation platform[1] and it's one the top most visited problem thread consistently implying many are searching for enabling hearing aid features on their wireless earphones.

[1] https://needgap.com/problems/22-enabling-hearing-aid-feature...

Most devices do not have an physical 3.5 plug anymore. Adapt or stay in an older (possibly more insecure) device ecosystem.

Or you can use an adapter.

My Pixel 3a, Pinephone, Librem5, Laptop, Xudoo, and Desktop still have them?

You do realize they make lightning/USB-C adapters to 3.5mm as well as splitters to allow for a chargers in parallel.

> Adapt or stay in an older (possibly more insecure) device ecosystem.

Gaslit by bigtech.

To go full circle: You can use a bluetooth receiver with a 3.5” plug

Can you MITM, deauth-bomb, or uniquely identify a 3.5mm jack?

You can inductively wiretap the wire

"Excuse me, please don't pay any attention to me attaching this clip to your headphone wire. Next passenger, please?"

I bet someone could still track you. Headphone wires can presumably act as antennas, and your specific music preference could be detected from a distance and used as a fingerprint.

Or more simply, track the actual phone if it doesn't have all it's radios off.

That's why phones have got MAC address randomization.

I have a phone that has a FM radio, but it only works if headphones are plugged in (whether or not you tell it to have sound coming out of them or the speaker)--it uses the headphone wire as an antenna!

Any conductive object can be an antenna. However, effective antennas are approximately 1/4 the wavelength of the radio signal being transmitted, or 1/2 the wavelength for a dipole antenna. Headphone wires, approximately 2m in length, could be effective antennas for 40 MHz or 80 MHz radio signals. (80 MHz, you'll note, is close to the 87.5 MHz-108.0 MHz FM radio bands, which might give you a clue why some phones with built-in FM receivers require the headphones to be plugged in).

However, music has frequencies in the range of a few dozen hertz to a few kHz, which is in the "ELF" and "VLF" extremely or very low frequency bands. Some communication occurs at these frequencies, but it requires high-power transmitters with antenna arrays that are massive civil engineering projects tens of kilometers long rather than 2m long. These transmit to submarines towing long wires at small, inefficient fractions of the target wavelength, because these frequencies can penetrate saltwater.

Also, the headphone cables are not a single wire, they're a pair a pair of wires, each side carrying both a signal and the return or ground loop.

You might be able to inductively couple to this loop, like you would inadvertently if you're running unshielded, separated speaker wires near unshielded, separated 60 Hz power cables with poor grounding - but at that point when you're running the receiver wire a few millimeters away from the target's headphone cable, I think they'll notice and object to your tracking attempts...

Yes, well I remember the stories of EMI-certified equipment radiating information that was being received by CIA agents in a van parked outside the building.

https://en.wikipedia.org/wiki/Van_Eck_phreaking

Van Eck phreaking relies on detecting radio waves produced by equipment like a CRT operating at tens of megahertz, a high-power VRM operating at 500 kHz, or frequency shifts in a processor clock operating at a few GHz. These wavelengths can be radiated by antennas of reasonable size. If someone was able to pick up radio waves off a headphone cable, it would probably be from the higher-order harmonics produced by switching power supplies in the amplifiers, not from the sound waves themselves.

Also, EMI certification just means that it doesn't generate interference that will damage other equipment and that it's not permanently damaged by external interference. It doesn't mean that it doesn't radiate any energy at all. FCC limits are pretty noisy when you're considering whether or not you can detect emissions with an active antenna.

Humans are antennas too, you can be tracked through WiFi. https://cs.nju.edu.cn/ww/papers/ubicomp16_gait.pdf

I always remember back to one of my electronics labs in college. We were trying to debug a circuit from which we could get no readings. The oscilloscope, with no working leads, was sensitive enough to detect our movements a few feet away from it...

Who else here has stockpiled backups of their favorite wired-only noise canceling headphones just in case?

When my last pair of Bose QuietComfort 25s bites the dust, I'll probably stop flying altogether.

I got tired of repairing them and the noise cancelling in the newer models is much better. Bittterly I've moved to Bose 700 after my 2nd QC25's noise cancelling died.

There is hope - I just discovered that the QC45 has just been released and the form factor is identical to the QC25, with bluetooth and no built-in voice assistant.

That is fantastic news, my primary gripe with the 700 is that the NC doesn't work in wired mode. Doubtful if they will change that though. Any source on removing voice assistant?

The chart comparing it to the 700 indicates the lack of voice assistant on the QC45. The PDF instruction manual states:

"You can use the headphones powered on or off when the the audio cable is connected."

I'm hopeful this all means what I want it to mean.

https://www.bose.com/en_us/products/headphones/noise_cancell...

Thanks, really hopeful. Not clear if powered on means NC, because that would be very good. I'd use my old QC25 cable with the mic in that case.

""You can use the headphones powered on or off when the the audio cable is connected."

I always buy Sony noise-cancelling headphones which work both in wired and wireless mode. In wired mode, they can be used powered on, with NC, or not, like an old-fashioned headset.

Their main default is relative fragility. However the latest I've bought (WH-1000XM3) have incredibly efficient noise cancellation. Also you don't need to install any app to use them. Unfortunately they replaced the easy-to-use play/pause/FF/RW button and volume rocker of the previous models with tactile gestures, but it's bearable.

I didnt get a certain android phone because it didnt have a headphone jack. Cut to a year later and I have only used wired headphones when I forget to charge my bluetooth headhpones.

Pairing is annoying but its just the electronic version of unplugging the headphones from one device and plugging them into another.

Maybe I'm just young, but I really like the simplicity of wireless headphones. No wires.

What is complicated about wires? Plug-and-go.

Any day I'll trade any complaints about "spaghetti" against blutooth connectivity, having to charge yet another one more device, the possibility of loosing the base media device because you absent-mindedly left it on the subway chair next to you whilst offboarding onto the platform...

Plug and go. And then they tangle. And then the weight of the cable pulls your ears down constantly. And then you have a string of cable all day dangling below your shirt that sometimes gets stuck on things. Thanks but no thanks. Humanity has moved on.

> Humanity has moved on

Pedantry aside, the parent comment is clearly in the set of humanity alongside yourself, and they made a clear argument for wires. While you might disagree with wires, this dismissive comment was unnecessary.

Speaking about the subway, I used to commute taking various types of trains and walking, and the wires were always in the way of my normal movements. I can't say how many times the earphones ended up unplugged, often painfully, also meaning everyone could now hear what I had been listening to—which felt like an invasion of my privacy as well as an annoyance to others. Even sitting (train, work desk, etc), I can't count how many times this has happened to me.

I've got a lovely set of headphones that can do either. They've got your standard Bluetooth headset features, but also a 3.5mm jack that works completely unpowered.

What is complicated about wires?

I'm from the generation that had just discovered CD players with "anti-skip" techology and Minidisc. I don't find wires complicated, but I feel wireless earbuds, despite potential loss of quality, more practical for things like commuting or working out. Even for phone meetings I like being able to put in earbuds and walk around, do laundry, etc., without having to carry my device or worry about wires getting caught. I would prefer a set that doesn't have tracking or voice assistance though.

You're young now. In 20 years you'll understand, after you witness a few "upgrade" cycles and see how technology consistently follows the lines of profits and planned obsolescence rather than higher quality or better price. Technology companies have to keep pushing new stuff on us, lest we actually collect enough devices to be satisfied and move on with what life is really about.

I generally agree ... however, the one point that lets wired down is their durability.

I spent 10 years not changing my favourite wired headphones (replacing them probably 10 times in that period).

I've been with my (pretty damned cheap) bluetooth headphones for 2 years now. Zero issues.

Oddly enough, I've had the opposite experience. I've tried wireless headphones, but inevitably, they break in subtle ways- like becoming unable to hold a charge, or not supporting more recent codecs.

I don't yank on the cords of my wired headphones, and they work for decades.

I prefer wired headphones too, especially in crowded trains (European) where everyone competes for a slice of wireless bandwidth. I'm expecting some wireless congestion sooner or later ;-) At home wireless is useful sometimes, e.g. when I need to move around while listening during a video conference.

> referring to the commercial availability of Bluetooth modules that can listen to messages sent up to one kilometer away.

Is this accurate? I had no idea.

Following the link it's not clear to me if you can use this module to pick up 'ordinary' bluetooth from a km away (as they imply), or if you'd need a similarly 'strong' special bluetooth on the other end to communicate over 1km.

The trouble is that traditionally, I think the permanent Bluetooth MAC was how phones knew to reconnect with devices like headphones so it couldn't easily be randomized. This was all designed in an era when people were less paranoid about how tech could be abused.

Admittedly, back then, there has been way less abuse of that kind of tech.

Its probably fair to say that tech was less abused in that era, not that people were less paranoid about it. Your run of the mill telemetry would have been considered spyware (a term that's nearly dead) back in the day.

I'm just so tired all devices being my enemy these days.

Finding high quality noise canceling without a voice assistant is getting harder.

My sense is if you can find a Bluetooth one w/o registering it with the company app and no voice assistant, privacy risks are low (compared to the cellphone in your pocket).

I have had a great experience with my Audio Technica over-ear headphones. They offer a great line up for most budgets. The feature I like the most is that many of their line up can be used wired or wireless!

https://www.audio-technica.com/en-us/headphones/type/wireles...

Thanks for the Rec

I have galaxy buds and I've turned off the voice assistant feature completely. For now, it is still possible.

Houston highways track Bluetooth to check for traffic speed. You can track cars tpms as well.

Reply on news.ycombinator.com