Using the Speech Synthesis Settings Menu
The voice synthesizer default menu allows you to define the voice, volume and rate to use:
You can select the voice to use, and apply effects to the voice to make it sound slightly different.
The windows default voices are of varying quality. You must have the voice pack installed for this to make any effect.
More voices can be purchased online. Ivona voices which are commonly used since they are compatible with SAPI 5 interface and can be purchased from www.textaloud.com individually. Voices must be SAPI 5 compatible to be used with EDDiscovery.
Beware free sound packs - they come in .exe installers and who knows what else is being loaded.