This app was mentioned in 21 comments, with an average of 2.00 upvotes
If you have Android, Google built in a phone finder that does exactly what you're talking about. You can also use the app Where's my Droid.
You can use android device manager, log into your email that youve registered the phone with and you can locate the phone and call it also.
Where's my Droid (https://play.google.com/store/apps/details?id=com.alienmanfc6.wheresmyandroid&hl=en) has been an app ive used with all my phones. Very efficient, even if you use the free vers
Never used the app but I stumbled upon it a couple of times. It might work for what you need.
Linkme: Family Locator
EDIT: I took a closer look to the app and it it seems more of a family socializing app of some short. Maybe it's better to use Cerberus or Wheres My Droid where they have ringing the phone capabilities etc.
Install Wheres My Droid from the web remotely.
https://play.google.com/store/apps/details?id=com.alienmanfc6.wheresmyandroid
That will allow you to track the phone, and, if you go for the paid version, even wipe it.
We did that when my GF lost her phone. Sadly, we tracked it to an apartment building, so the police couldn't do anything as the position wasn't distinct enough to get a positive fix on a single apartment.
Can't figure out Tasker, but I've used "Where's My Droid" forever on my phones to accomplish exactly what you're asking.
https://play.google.com/store/apps/details?id=com.alienmanfc6.wheresmyandroid
I've not used them myself but I know there's apps that will cause the phone to ring, even if on silent, upon receiving an SMS of a keyword like "locate" or something, which might suit your needs.
As I say, I've not used them myself so can't vouch for their quality but a little searching showed this as a option to maybe start with.
https://play.google.com/store/apps/details?id=com.alienmanfc6.wheresmyandroid
For everyone in this thread who can relate, there is an app that will turn on your ringer for you.
I don't think this app works on iPhone.
using Where is my droid since 2014 but fortunately I ve been never in a situation of stolen phone, but I tested the features of this app vs. Google Device Manager / Cerberus and few other which won't locate your phone if it hasn't the GPS activated.
Basically, you send a specific SMS code to phone to activate GPS / camera / ring / lock / wipe SD etc
https://play.google.com/store/apps/details?id=com.alienmanfc6.wheresmyandroid&hl=en
One-time app install with easy multi-phone doing. It's called Where's My Droid and you can text it 'wmd ring' from any phone and it will put all the volumes up and ring until you find it and hit the 'I found it' button.
You can also send 'wmd gps' and it turns on GPS and sends you the coordinates, so if she left it at a friend's house it will tell you which one.
For multiple phones, you can just text the numbers in a group text or individually.
It's not exactly what you're looking for, but I think it's a pretty fair compromise for ease of access and usability. There is also a light version.
https://play.google.com/store/apps/details?id=com.alienmanfc6.wheresmyandroid&hl=en
The app Where's my droid is good for that. You send it a text and it turns the volume from silent to max and begins ringing. You can also text it for the GPS coords to open on google maps.
Sorry for your loss OP!
Now is the time for everyone to download Where's My Droid or preferably Prey. Seriously. You spent $300+ on a device and loss/theft is the dumbest way to lose it because it's EASILY AVOIDABLE.
where's my droid can do that but it would have to be pre installed before you lost it.
that's exactly what wheresmydroid does.
Had to use it more times then I'd like to admit :-/
I remember Where's My Droid worked pretty well several years back, haven't tried it recently. https://play.google.com/store/apps/details?id=com.alienmanfc6.wheresmyandroid
Get this app and the pro version:
https://play.google.com/store/apps/details?id=com.alienmanfc6.wheresmyandroid
Drop the 4 bucks for the pro version. You can remote lock, take pictures etc.