Sending Voice Announcements via Alexa Using SinricPro

The Amazon Alexa Smart Home API does not natively support sending arbitrary voice announcements (i.e., custom text-to-speech messages). However, you can achieve this functionality indirectly using only officially supported methods by combining Alexa Routines with a Switch in SinricPro.

Method: Alexa Routines + SinricPro Switch

Follow these steps to enable Alexa voice announcements triggered from your SinricPro integration:

Create an Alexa Routine
In the Alexa app, set up a new Routine that speaks your desired message. Configure it to be triggered by a specific smart home event—such as “When a smart device turns on.”
Add a Switch in SinricPro
In your SinricPro dashboard, create a new Switch device (this will act as your virtual trigger).
Trigger the Announcement
From your application or server, send a SinricPro sendPowerStateEvent event to turn on the virtual switch. This action will activate the Alexa Routine, causing Alexa to speak your announcement.

Example code for ESP8266/ESP32:

void triggerVoiceAnnouncement() {
    SinricProSwitch& mySwitch = SinricPro[SWITCH_ID];
    mySwitch.sendPowerStateEvent(true);
} 

Note: This approach leverages only Amazon-approved mechanisms and does not require any unofficial workarounds.