Siri on your Mac
You can talk to Siri on your iMac and use your voice for many tasks. For example, you can find files, schedule meetings, change preferences, get answers, send messages, place calls, and add items to your calendar. Siri can give you directions (“How do I get home from here?”), provide information (“How high is Mount Whitney?”), perform basic tasks (“Create a new grocery list”), and much more.
Note: Siri may not be available in all languages or in all areas, and features may vary by area.
Enable Siri. Click the Siri icon 
Tip: To learn about more ways you can use Siri, ask “What can you do” at any time, or click the Help button 
, then click Today. If you’re checking a sports score, for example, results stay up to date.
Change the voice. Click the System Preferences icon How to use Siri on your Mac.