In college our underwater acoustics prof used an old copy of the Navy sonar manual to teach some fundamental concepts early on in the course. One of my favourite passages was when the Navy manual definitively answers the question of "if a tree falls in the forest and nobody's around to hear it, does it make a sound?" The answer, according to the Navy is that no - in order for a sound to exist there must be both a transmitter and a receiver component, and if both are not present then the energy emitted by the lone transmitter does not constitute "sound."

So, according to that - you're both right in that it's a two party process. However, I believe the term is appropriate in underwater acoustics for anything which dumbly sends out a relatively predictable signal on a regular interval.

The problem here is designing a microphone that is sensitive enough to listen for a page from a passing search vessel and also survive the crash.

I worked on a project involving this type of underwater audio beacon, and everyone called it a "pinger." So it's not just the media.

The GP's point is well-taken. The company that produces this particular widget calls it an "underwater locator beacon",[1] not a "pinger".

To "ping" implies you are the locator, not the locatee, whether you are sitting in front of a terminal window or are running the active sonar[2] on a boat. You send a signal out and await a response, be it a reply (as in the case of the ping command) or an echo (as in the case of sonar).

[1]http://www.radiantpowercorp.com/dk-series-underwater-locator...

[2]http://en.wikipedia.org/wiki/Sonar#Active_sonar

> To ping means to send out a signal in expectation of maybe receiving an echo or reply. It's a two-way process.

"Ping" is an Onomatopoeia. There is no distinction about whether or not you are supposed to get a response or acknowledgement in the definition of this word - this is your own view of the definition, perhaps biased by years of working with computers, but in the acoustic world a 'pinger' is just something that 'goes ping'.

>I find it annoying that the media call this thing a "pinger".

I find it annoying when people assume their definitions of words they use are the only 'right ones'. Use a dictionary - you'll see the definition right there:

    pinger  (ˈpɪŋə) 
 
    — n
    a device that makes a pinging sound, esp one that can 
    be preset to ring at a particular time

No. I hereby execute a proof by Monty Python: https://www.youtube.com/watch?v=arCITMfxvEc