Will a siren go off if someone breaks into my home?

@sharczak there is a siren in the top of the base that will go off IF a sensor is tripped, preferably a sensor set to instant trigger.

But, if you're depending on your neighbors to hear it in a real world alarm event to possibly assist (like a real burglary or intrusion), I don't believe the base station's siren sound is loud enough for that (at least that I've noticed).  The base station's volume itself isn't horribly loud, even at it's highest setting (for example, if your base is on main level of home, and you're sleeping in an upper level of the home, you most likely won't hear the base announcements).  The siren has 3 volume levels to choose from, all of them being fairly ear-piercing, depending on your level of comfort from the loudness.

The base station's light can be turned off in your settings.

I have several closed doors between base station and where I sleep.  I bought a basic baby monitor and put the "baby" portion near the base station, and the "parent" unit in my bedroom.  When the alarm goes off (and have had a couple of false alarms), it is a "wake the dead" level loud.  Also did the same to have one down in basement.  This way I also hear the base station announce if entry sensor is open, or when mode is changed.

Many folks must have huge homes or have much thicker doors and walls than in my house.  2600 sq ft two story colonial and there is no way you would have issues hearing the base and 1 aux siren.

^ and yet, the volume level on the base has been an issue since version SS2 - I don't know why SS can't provide a high enough volume level on the base, if it can be turned down, then what's the problem - bet it won't happen with SS4 either!

One might suggest there is a practical limit to what sort of output can be expected from the constraints of rather small device, small speaker/piezo element. Acoustically, even if the output were doubled, a 3dB increase, it would sound only slighly louder. It would require about ten times more output/10dB increase to sound roughly twice as loud.

I get that (sort of), but I don't believe it would be an impossible feat.  Thousands of tech gadgets out there with sufficient sound level options, much smaller than SS' base station.   The sirens are pretty pricey as it is, so there's a slight roadblock for some folks.

The optional supplemental siren is VERY loud (195db) and costs something like $60 USD.  I have it because when I'm in the shower and I'm not wearing my hearing aids, I can't hear the Base station siren.  I have it on good authority that the Police take a dim view of people ignoring security system sirens.

It's loud enough that it can be heard ALL OVER the house!  And can even be mounted outside.  It adds an extra layer of comfort for my SS Smoke detector, and SS CO2 detector as well.  Personally, I think it is money well spent since I can place the siren in a different location from the base station.  I think with thoughtful placement of the base station, the current alarm siren is likely loud enough for most people in most situations. I should think the engineering and design costs that would go into a "beefier" base station siren would likely raise the entry cost of the system as a whole, making the system less affordable to users inclined to investigate the SS System.  I think making an auxiliary siren available for those who need it, makes the most economic sense for the customer, overall.