Nice find by Tera Thomas O’Brien on how to change Siri’s English voice to male, Australian, British, Irish, or South African (the latter two are female only).
Siri on my Mac is British. And male. Siri on my iPhone is English, too. But female. Here’s how you can get different voices and dialects for Siri. Let me start with the Mac first. It’s easy. Open System Preferences in macOS Sierra. Click the Siri icon. Click the Siri Voices drop down menu.
Easy enough. Takes about 15-seconds, tops.
Voila. New Siri. For my Mac I chose the British voice. For the iPhone I chose British female. For my iPad I chose Irish female. Now I can tell who is talking to me.