Is it possible to change the tone of the car alarm?

More importantly, can I upload my own?

I drive a 2009 Pontiac Vibe 4cylander 5 speed manual trans.

I’m curious to know about the alarm system.
How does it work?
How difficult would it be to change the sound the alarm makes?
Would it be possible to upload a custom sound?

I’m not sure if this is possible as a DiY project or if it would be better to try to go through a dealer or customs shop.

If anyone has some thoughts or experience on the subject, I’d love your input.

If there is a way it’ll describe it in the owner’s manual. Have you looked?
The Pontiac Vibe is a “rebadged” Toyota Matrix. The Toyota dealers parts window might be able to provide a protocol for you as well.

Is not the “alarm” the horn?

Good point. If it is, it can be changed by changing the horn unit… but not necessarily to something less aggravating. That would also make “downloading” a new sound impossible.

“I’m curious to know about the alarm system.
How does it work?”

A lot depends on whether this is a “factory” alarm system, or if it is an aftermarket system.
What can the OP tell us in this regard?

If this is actually an alarm and not just the warning chime sounding inside the car, the question is moot. No one pays any attention at all to car alarms as a theft warning.

The universal response is “will someone shut that stupid alarm off??!!”

In any case I doubt very much there is any way to do this on a factory or aftermarket alarm.

“I doubt very much there is any way to do this on a factory or aftermarket alarm.”

Maybe yes, maybe no…
On my '92 Accord, the aftermarket alarm system had a variety of annoying sounds from which to choose.
IIRC, there were about 6 different “tunes” that it could play in order to–supposedly–attract people’s attention.

I think just paging through the JC Whitney catalog would give some options for replacing the factory horns. Like the Ahooga one. I’m sure there is one that plays Dixie too. Sheesh to what end, I dunno.

‘‘PROTECTED BY VIPER, STEP AWAY FROM THE VEHICLE’’

I’m curious, 'cuz you never said…
What do you expect or want it to sound like ?

Huge thunder right now, my screen may go down.
Look at the weather radar where I-40 crosses from NM to AZ. That thing was not there an hour ago but it’s building fast and headed my way. KABOOM!

2:30 mdt
Told ya so !
Screen black, sodium shop lights off, radio station off, sodium lights back on to dim…

One of the funniest things I’ve seen in a long time was. A car hooked to the back of a tow truck leaving my neighborhood all the while hearing, ‘PROTECTED BY VIPER, STEP AWAY FROM THE VEHICLE’’ over and over as it headed for the highway.

Stop or I’ll shoot. Stop, stop. I really mean it. Stop!

If you are concerned enough to need an alarm system on your vehicle…
Make sure you buy one that pages you, so that you know and can go check it out.
Too many are just parking lot noise makers that no one pays attention …because…
Too many owners are not within earshot to respond anyway.

I agree with @Mustangman that car alarms are for the most part…useless. They are universally accepted as noisy nuisances though.