Question

I am writting a spelling word application for my son and would like recomendations for good APIs that can be understood when it speaks. I am programming in .Net so something that will interop with that would be handy. Thanks in advance.

Answer 1

MS Speech SDK.
It is exposed via a .NET assembly. Very easy to use. My kids loved it. Free.

using System.Speech.Synthesis;

public class SpeakHelloWorld
{
  public static void Main(string[] args)
  {
      SpeechSynthesizer synthesizer = new SpeechSynthesizer();
      synthesizer.Speak("As for me and my house, ...");
  }
}

The sounds generated by the code above do not use natural inflection, with pauses and so on. So with a complete sentence, it does not come out sounding human. But single words sound ok, just sort of robotic.

For a little kid, with a small enough set of words, you might want to just record your own voice saying the words. I did that with a USA state puzzle, to pronounce the state names, rather than resort to the synthesizer.