on iPhone 5s on iOS 9.0.2 siri will not speak in American English but will in British English. Any help would be appreciated.

I have an iPhone 5s running iOS 9.0.2 and siri is no longer speaking her answers. They appear as text but are not spoken. Now it is true that if I switch to British English she will speak them, but as this is used by my 80 year old mother I really need American English to work. Have tried restarting the phone, hard restarting the phone and many other things. Any help would be appreciated.