Signal on laptop
 

Can anyone explain this ?
Sitting in an adjoining room some distance away from my laptop, which was switched on, I heard a bleep then a girl's voice saying, hesitantly, " hello". I went towards the laptop and heard a few indistinct noises then it reverted to it's usual silent desktop state.
I'm reminded of a time, in the 1960's, when my desk dictaphone recorder, connected to the mains, picked up a very clear conversation between two water authority employees.
I can vaguely understand that a wifi connected device can pick up something from the ether but I've never worked out how the dictaphone did.

Nothing to do with WiFi - the O/S controls all activity and only programs that are loaded can operate the sound system.
Do you ever use Skype? If this program is loaded in the background by default (at boot time) it is theoretically possible for someone to call you if you have Auto-answer enabled. Also, if you were on the internet at the time that you adjourned to another room it is possible one of your previously visited websites could be running a video (advert or similar) in auto-play mode.
Otherwise I suggest the "hello" was issued by another device, not the computer. A mobile phone perhaps?
Computers are quite "clever" but are still dumb terminals that do not in fact have a life of their own.
It is good practice to shut down any program that is not actually needed if you are going to be away from the computer for an extended period of time.

Thanks P Dev
The laptop is capable of Skype but I've never downloaded it. I had been on the internet. I returned to the desktop afterwards. I was long enough away from the machine for it to have gone into the black screen. There are three mobile phones in the property. None were switched on.. There is no other device near the laptop.
The girl's voice which said "hello" had a surprised inflexion as though the ringing on ( presumably ) her phone was unexpected.
Baffling !

papajuliet wrote: Tape recorder playback heads can often pick up AM signals nearby. In around 1966 our school CCF '12 Set' transmitted into an end-fed wire at around 5 MHz. Being ignorant, we didn't know how to tune the antenna, so instead of minimum dip on the 'wavemeter' we tuned it for maximum deflexion...:eek: Causing very high SWR and lots of interference.

As a result, my guitar playing chum practising nearby would often hear us talking when he used his echo chamber - a somewhat primitive device which used a tape loop, one recording and several playback heads for the echo effect!

It's a tragedy... she is still trapped inside poor girl!

It is perhaps something like Amazon's Alexa being active and picking up noise.

Are you sure you didn't inadvertently butt-dial your mobile phone?