Hello, I'm an English teacher teaching listening to beginner level students at university and I'd appreciate any help / advice from those of you familiar with using Text-to-Speech. I have two questions: 1) I need to type short sentences like "Hello, I am David Smith." and "I am a doctor." followed by sentences like "I am 36" and "I am married." The problem is no matter how slow I have the text read I find the breaks between sentences is too short. Is there any way to extend those breaks rather than everything being read out in huge chunks? I've tried spacing, or several full stops or even hyphens, but I'm not sure it's made any difference. If anyone knows what I can do about this, please help. 2) I've observed that Samantha and Alex to be the only voices that my students can understand and do not find robotic. I don't think the other voices are any good. Does anyone agree with me on this one and is there a way to find more "natural" voices? If so, how do I get them? I'm a new Mac user, so please explain it in the simplest way if possible. I have MacBook Air and use Yosemite 10.10.5 in case it helps. Thanks a lot, everyone!