Like many users I have English (UK) x-gba-local selected for warnings. Everything works fine and I get warnings for both navigation and traffic when using SkyEcho (+FLARM). These are bluetoothed through to my headset. 

However at my base of Hawarden we have Padeswood Cement factory a few miles South East and if the 'Produce Speech for Warnings' is selected the whole take off and climb out on Rwy 22 is peppered every few seconds with warnings for the proximity of the chimney and then with warnings for the Pepze CTA at 3000' above. Obviously this is fine if you want those activated. Sadly, with a busy ATC environment they can also be very distracting. 

The problem seems to be that every time I disable the voice in 'Setup/Navigation Options/Produce Sounds for Warnings' she's back the next time I go flying! I can only presume that it's a software anomaly associated with map or document updates as I don't use SD on my Android tablet when away from the aircraft. 

Am I missing something or will I have to remember to deactivate the voice every time I update the tablet? 

Deactivating "produce sound for warnings" will not turn off speech. I think there's a separate option for that.