audio triggered power switch

[Kabletor]

I have an external amplified speaker connected to a tablet via standard mini-jack.
The amplified speaker is always connected to its power supply.

I'd like to add a circuit that when an incoming call arrives to the tablet, the incoming audio signal will trigger the circuit and make it act as an automatic power on switch for the speaker.
As long as the conversation goes on, the speaker will be powered.
After a configurable time (let's say 3 minutes) of silence, the circuit should switch the speaker amplifier back to off.
Do you know if such a circuit exist ? or someone who can build it ?
Thanks in advance!

 

[MAAC0]

I presume Your tablet puts the ringtone on the audio jack. If not You could use a mic. Check for Sub schematics, they usually are in stand-by and operate sensing sound.
My JBL does it as it did the old Sony.

 

[Kabletor]

Thanks MAAC0. Yes, the ringtone has been redirected to the audio jack.
In the meanwhile I have found this pre-built audio signal controlled relay switch board with user adjustable input trigger level sensitivity: Cebek PM-11 (CPM011) - Audio Signal Controlled Relay Switch Module. You can find the link here.
Since I need a delayed power cut-off after the input signal ends, it also offer integration with this additional module: Cebek I-30 (CI030) - 12Vdc Re-Triggerable Delay Timer Module, 1 to 180 Second. Here.
Did anyone ever tried it ? Would that combination work ? Anyone could suggest how to connect the two modules together ? Sorry, I know what I need to do, but I have no knowledge of electronics. THANKS !

 

[MAAC0]

Have fun reading. All off his site has valuable information.

Project 38

 

[Kabletor]

Thanks MAAC0, really appreciated.
Unfortunately that circuit is way too complex for me to understand.
I need to find either something ready on the market which I just need to assemble.
OR an audio engineer who will help me designing the entire board.
I just ordered the Cebek PM-11 (CPM011) board and I'll let you know how it goes (if I'll find the way to connect it! )
Thanks!