I have this problem too on my new iPad Air.
Apples explanation is here:
In general comes a clean iOS install with so called compact voices. Those are the ones that sound robotic. As soon the device knows what language you are going to use, it will download the natural one. (Power and Wifi required just as with backups.)
After reading some of the rumors and assumptions in other Siri voice questions I like to add:
- the voice is generated on the device, not on Apples servers, thus a high load in the backend wont result in a bad voice quality.
- including all voices for all languages in the initial OS install packet would increase the size massively and waste space on the device you rather want to use for documents and Lapps. Downloading localizations is sensible common practice in app's. (See Where is my Water 1 from Disney on the iOS App Store for instance)
Does anyone have a fix for this issue yet? The Siri on my iPhone 5 sounds dreadful, while the Siri on my iPad Air sounds great (and no, it's not a speaker issue, since the issue is present over headphones as well). My Siri location is set to Canada / English.
It's definitely not a settings issue... it's some sort of software bug. The enhanced voice has downloaded on my iPhone, and is shown as active in Settings. Likewise, in the VoiceOver settings, 'Use Compact Voice' is set to off.
I have tried switching languages, disabling / re-enabling Siri, disabling / re-enabling 'Use Enhanced Voice', erasing all settings, and even erasing all settings and contents (factory reset) followed by a restore from a backup. Nothing has worked... It's incredibly frustrating!
I too have found a solution, but it's ugly. What worked for Helge did not work for me.
My solution was:
1. Navigate to Settings > General > Reset All Settings. It is NOT necessary to erase all content.
2. Manually restore all of my custom settings, one at a time (which took about 1 hour). Do not restore from a backup.
As you can see, this isn't an ideal solution, but it worked. Fortunately, all of your media is retained (music, photos, videos, apps, etc.), as are certain settings like the home screen layout, email accounts, and app data.
Was it worth it? Definitely. I no longer want to rip off my ears every time I use Siri.