Open Radar

 
Summary:
Apps that set the AVSpeechUtterance "rate" property do so to make speech an appropriate speed for their app use case.

Under iOS 8 (later betas and including GM), the same rate value as iOS 7 gives speech that is approximately 50% faster on iOS 8. 

This is effectively breaking apps as it is not clear if this is intended or a bug. To workaround it we can adjust our rates but a future iOS 8 release may change this again and break our apps as then speech would be far too slow.

Steps to Reproduce:
1. Open example project in Xcode 6
2. Deploy to iOS 7.x device 
3. Run, press Speak - note the NSLog shows the time of speech start and stop. Approximately 8.5s
4. Deploy same code to iOS 8 device
5. Repeat step (3). Notice duration of speech indicated in NSLog is approximately 7.1.s

Expected Results:
The speech rate should be identical. In both cases the code is specifying a rate of 0.5

Actual Results:
On iOS 8 the speech is approximately 50% faster

Version:
iOS 8 GM

Notes:
Included in the project is a multiplier factor for the rate, of 0.6666f. If you uncomment this to adjust the desired rate, iOS 8 will speak at almost exactly the same rate as iOS 7 did at the non-multiplied rate.

Configuration:
Any iOS device on iOS 8