I've heard this concept called the cardboard colleague - you explain the problem to a cardboard cutout representing a colleague instead of an actual person.
Of course it remains a concept, I don't think anyone would go so far as make one :-)
Many years ago when I was designing and programming embedded controllers (early '80s) I worked alongside, but not with, another engineer who was building devices using the same fundamental components (6520, PIA, etc.) In our tea breaks we would explain our problems to each other. Neither of us suggested any solutions to the other or responded with anything other than simple platitudes and sympathy for each other's troubles. It was remarkable how many problems had simply vanished by the end of the tea break.
I found the break in a 10m extension cable, by measuring the capacitance at each end and calculating the ratio of the two values. This predicted a break at roughly 1m from one end. Then started probing the cable from 10cm towards the ”short” side, moving towards the long side. Found the break within 15cm, saving roughly 9m of cable.
That's pretty clever. Also if you are interested (not 100% applicable because it's not something most people can do at home) there is a practice for finding breaks/partial breaks in cables using time domain reflectometry (TDM) [0]. You send a pulse in to one end of the cable and measure how long it takes for some reflected energy at the break to return. It's pretty cool stuff and you only need access to one side of a cable. I have used this in my job for finding discontinuities in large RF cables.
If you do have some electrics equipment at home (o-scope, sig-gen) you can make do it yourself [1]
We did this in the Navy to check circular wave guides to the ECM antennas in the leading edge of our bombers wings. We had to do this once every 6 months (I think) with a sweep generator to see if the cables needed to be replaced. Also, installing these were a complete PITA! Nothing was a straight run to where it needed to go, so you had to bend them as gently as possible as you fed the new line into the wing. Then you had to test it again.
These were very expensive and I've seen more than a few screwup's while installing them.
A coworker's cat-5 tester also has a TDR function that shows you where an issue is on the line.
Many _many_ years ago we used to have to do that on occasion in our office to find where the break in the coax network was. That brought some amusing memories back for me, thanks :)
I got the capacitance idea from having worked with TDR in the late 80's. As students we used them to tune FM antenna combiners, but I never quite got the hang of it at the time.
Unless there was an obvious reason for the break then there could easily be another "nearly broken" fault in the cable e.g. if break was due to stretching.
A partial break has the risk of local overheating.
So perhaps you should biff the cable anyway if it is likely to be unsafe?
This is a good point - the cable is probably 20+ years old and has been used for weed eaters and lawn mowers. It's been regularly uncoiled and re-coiled, not always correctly.
One doesn't actually have to listen to anything through the headphones.
I've used noise cancelling without music in the past.
I also have a set of earbud rubber thingies that have been stoppered with hot glue and a short piece of hollow lolly stick.
Those fit better (don't feel itchy after long periods) and provide more isolation than the squishy yellow ear protectors.
The only way NC headphones block conversations is because they are also acoustically isolating. That is, they would block conversations even with the NC feature turned off. The headphones you link to look like this: they're basically earplugs with headphones built in. Earplugs block conversations because they physically block sound waves from entering your ears. The same principle works with the big over-the-ear cans. It's not the NC feature that's helping, it's the fact that the headphones themselves are isolating your ears from the outside world.
Hmm, interesting. I wonder if it's because they fit in the ear, rather than sitting outside like more traditional headphones. This would allow them to cancel noise at higher frequencies since the driver-to-eardrum distance is smaller.
Have you used other, more traditional can-type NC headphones? Can you compare?
