Miscellaneous Things You Need to Know About Macs
The Mac can respond to your spoken commands.
Open System Preferences, again under the Apple menu, and choose Accessibility. Select Speakable Items from the listing on the left. Now, click to turn on the Speakable Items button. A round microphone feedback window appears on your desktop, with the key or keyword you need to press to alert the Mac that you are about to speak.
Press the Escape key to start barking out commands, or change the listening key or other behaviors by clicking the Listening Key tab.
To check out a list of the commands your computer can understand, click the little triangle at the bottom of the feedback window and then click the Open Speech Commands window.
Click Calibrate to improve the performance of your internal (or connected) microphone. The calibration process involves adjusting a slider and speaking aloud the phrases listed on the screen (such as Open a document and Show me what to say) until the computer makes these phrases blink in recognition.