Tom Tom Go Mobile Samsung Galaxy S5

[polkay]

I have the Tom Tom Go App installed on my Galaxy S5..initialy I had problems starting the program...found it was installed on phone and some files on SD card...Tom Tom advised installing everything onto the phone memory. This I have done by reducing map coverage to UK & and runs fine however no matter how I try I cannot get voice prompts to work...routing is fine on the map ;lack of speech is the problem...
Can anyone help.

Danny