can AVSpeechSynthesizer solve speech recognition in background? : unfortunately, i didn't find any solution to recognize user speech in background, I just yesterday read about AVSpeechSynthesizer. sorry i didn't read a lot about AVSpeechSynthesizer and I should submit my project on Thursday. really I need to solve this problem, so any one know about AVSpeechSynthesizer is it possiable to help me when I want to recognize user voice if he/she say specified word? for example say "hello" in background. 


thank you for your time.