If you've got a really strong regional accent, or something like Dick Van Dyke's legendary cockney accent from Mary Poppins then you might get the occasional "Sorry, I didn't catch that." As it happens, I am a genuine cockernee myself, and it was only OK Google that understood my exaggerated "Cor blimey, guvnor!" when I tried a Dick Van Dyke impression as a test.
Friday, May 27, 2016
Gor Blimey, Siri!
Macworld, April 25, 2016, "Apple Siri vs Microsoft Cortana vs Google Now vs Amazon Echo Alexa: Which is the best voice control technology?" by Cliff Joseph