Using the voices with VoiceOver
48kHZ was lower pitched, while the 24kHZ was slightly lower, which suggests that voiceover uses a sample rate of 22.05kHZ for its 3rd party voices. The Siri voices work fine with voiceover, and they have a higher sample rate. This seems like Voiceover doesn't recognize the sample rate of the voice. The voices pitch is fine on iPhone. The voices are very sluggish in general. If these issues could be fixed, I don't see why I wouldn't purchase a few voices for my devices.