- Firstly, make sure that you are connected to Wifi.
- Open the Settings app, and then choose ‘General’ (first option in the third block).
- Tap ‘Accessibility’ (last option in the second block).
- Tap ‘Voiceover’ (first option).
- Scroll down and then tap ‘Languages and Dialects’.
- Tap ‘Default Dialect’, and then tap the ticked option – ‘British English’ in my case.
- On the same screen, tap to enable ‘Enhanced Quality’ at the bottom.
Your iPhone or iPad will now download a little over 200 megabytes of data which includes higher quality voice for Siri. Once it has downloaded, you should find that Siri’s voice is back to how it was before and is clear enough to understand.
I’ve heard that iOS 7 should install the enhanced quality voice pack for the selected language automatically, whilst your device is idle, plugged in and on Wifi. However, this hasn’t happened to me yet. The method above therefore forces your device to install the higher quality voice manually.
Many thanks to the people in this MacRumors forum thread for the instructions.