VoiceOver and the NEW Thai TTS

I tried to install iOS 7.0 Beta 3 on my iPhone 5 and I found a big change of TTS used in my native language. I'm Thai. I find the earlier version of iOS used a clearer Thai TTS output. What should I do if I have some comments or would like to contribute to the localization process of Thai TTS for Apple? I believed that the upcoming release of iOS 7.0 will strongly effect Thai blind people who are familiar with the old TTS and may refuse to adopt it due to unfamiliarity.