Not beep, ping.
While the “beep” has been around for a while, it wasn’t until the advent of cheap piezoelectric transducers that they became ubiquitous. Development was driven by a Japanese research consortium established in 1951, with high-volume commercial applications beginning in the mid-60s and ramping up through the 70s. From The History of Piezoelectricity:
I know I am not the only one of my ‘generation’ who continued to refer to my pager as a ‘bellboy’ long after the next generation didn’t have a clue what I was talking about.
“Jeez, my bellboy’s not working today. You’ll need to call locating directly”
“What?”
This makes sense. In the 70s ‘beeps’ were in a number of electronic devices like computer terminals and consumer appliances like microwave ovens. Low cost consumer electronics weren’t quite there yet. I do remember the game of Operation used a buzzer, it would have added a couple of cents to the manufacturing cost to create a higher frequency beep. (a few cents was real money in the 60s, though still is when it comes to making safer cars and other unimportant uses :rolleyes:)
The Apple ][ was one of the first PCs to integrate sound with their product. Most PCs before that required an external terminal or used a TV interface without audio.
Times are a changing. Someone has realised that anyone surrounded by a cacophony of beeping machines will simply tune them out. The modern way is for medical monitors to only beep when something needs attention.
Interesting. There were only 5456 combinations possible, a real limitation.
NBC radio used this sound on their weekend programming from 1955-1975.
Just by the way, the word seems to have first appeared in print in 1927. It is listed and interjection. I would have figured a verb and noun.
I don’t know the answer, but surely the first boop soon followed.
I think many of you are missing the point.
PiQ isn’t asking when the word BEEP was first used, nor when the first beep sound was ever used, but when the first commercial product used an actual electronic beep.
Watches with alarms used mechanical buzzers into the 70s at least. Our first microwave (early 70s) had an actual mechanical bell, and a mechanical timer. Cars BZZZTed if you left your keys in the ignition. Nothing in my stereo system, games, toys, appliances, CB radio, whatever, beeped in the 70s or earlier.
But somewhere in to 70s beeps came of age. Jim Rockford told you to leave your message after the beep in 1974. Digital watches (probably LED not LCD) started beeping (on the hour! Glad that didn’t last!) sometime around then. Heart monitors beeped out the beep beat back then, but that was specialty equipment. Should it count?
So when did consumer electronics start getting beeps? The Apple II was mentioned. Was that the beginning?
And for the record, not only did the Road Runner go meep meep not beep beep, but the sound wasn’t electronic, it was Blanc-onic.
A simple oscillator creates a tone - which turned on and off, created beeps. I assume the morse code system was predicated on beeps - I would expect clicks are rather hard to follow; use that open/close circuit to interrupt a tone, and you get beeps… which were then turned into radio transmissions. The radio Morse IIRC was reasonably common about the time of the Titanic sinking in 1911.
The earliest sounds would have been mechanical - the bells of an older telephone, or a buzzer. To create a higher-pitched tone required electronics since mechanical devices could not oscillate that fast, so probably needed transistors; a tube-based oscillator just for a sound (rather than a collection of electronic uses) is overkill.
(Did they make crystals before the days of transistors that oscillated in the audio range?)
They didn’t use crystals, but there were plenty of tube-based oscillator circuits. These types of circuits were common in early radio transmitters. They tended to rely on LC filters (inductors and capacitors) instead of crystals. LC filters drift a lot more than crystals, so the oscillation frequency isn’t as stable, especially as the components heat up and cool down.
Some of the first oscillators were actually intended to be amplifiers, before they properly understood feedback and stability. 
At least one patent for an oscillator had its roots in a poorly designed amplifier.
The earliest radio oscillators were based around electrical arcing combined with bandpass filtering. This works well enough for something like Morse code, but isn’t consistent enough to be used to broadcast audio signals. Google “spark gap oscillator” if you want the gory details.
You are describing a CW (continuous wave) transmitter. These were not possible until the invention of the electronic oscillator in 1913 and were not in common use until after WWI. The Titanic used the more primitive spark gap transmitter, so no beeping.
As I mentioned in an earlier post, the beep became ubiquitous when cheap piezoelectric transducers became common in the 70s.
It’s not at all hard to make a relay that can produce a high-ish tone buzz.
As to audio crystal oscillators, the first application was for sonar in WWI. But that has fairly high pitched. Piezo crystals were used in audio applications going fairly far back. One common application was in early electronic phonograph cartridges. So making audio-level circuits using crystals was no big deal.
The technology is pretty low to produce a beep. The question is when was one added to a product.
And her name was Betty. 
The first beep I can personally recall was from my Sinclair Spectrum in the early 1980s. There was even a specific BASIC command called BEEP, so you could get the Spectrum to play (very tinny) music.
Once you have a microprocessor, you no longer need an oscillator circuit. You just need something that can drive a speaker from one of the microprocessor’s digital output lines (a single transistor can do the trick). You implement the “oscillator” in software by toggling the I/O line on and off at the desired frequency.
Since the microprocessor can only drive the output high or low and not to any intermediate value, this limits the types of sounds that you can make.
Many of the 8 bit computers had a speaker so that they could beep. The ones that didn’t often had fancier sound chips inside of them so that they could make more complex sounds than just beeps if they were connected to a TV.
I remember a quick scene in A Night to Remember where the radioman sits down and starts keying. A zap, zap, is heard and I thought, “Hey! A spark gap transmitter!”
I think it was before the iceberg when they were showing how swamped he was with traffic from all the swells.
If you’re on a highway and Road Runner goes beep beep.
Just step aside or you might end up in a heap.
Road Runner, Road Runner runs down the road all day.
Even the coyote can’t make him change his ways.
source: Road Runner Lyrics - Theme Song Lyrics
The first beep I can remember was in my parents’ car. It beeped a naggy warning if you didn’t buckle your seat belt. Or at least it did until my uncle borrowed the car and while he had it he cut a wire so it didn’t beep anymore. This was well before there were any laws requiring seat belts to be worn (at least in America).