Would I be able to change the speaking voice of OpenEars to another? I don't quite like the the default one. Is that possible or would I have to use another API. Sorry if this is a stupid question.
Yes, you can, but it's a bit complex process. Openears uses Flite for speech synthesis, so you need to change the voice in Flite. Flite supports 13 voices to choose already and you have an option to build a new voice.
To build a new voice you need to follow the documentation. A festvox documentation might be also useful for you to understand the basics.