Try with a default voice first and do this:
In the JS function store the blob in the global var
runtime.globalVars.AudioDataURL = URL.createObjectURL(blob);
Then in the event sheet:
-> AJAX: Set response binary to BinaryData
-> AJAX: Request AudioDataURL (tag "mysound")
+ AJAX: On "mysound" completed
-> System: Set AudioDataURL to BinaryData.GetURL
-> Audio: Add remote URL AudioDataURL (type "audio/mpeg; codecs=mp3") as name "voice"
-> Audio: Play "voice" not looping from Sounds at 0 dB (stereo pan 0, tag "")