Choose Apple menu > System Preferences and click Speech.
Click Speech Recognition, then click the On button next to Speakable Items.
The speech feedback window appears on the desktop and shows the "listening key" that you'll need to press before speaking any commands. (The default listening key is the Escape key.)
If you don't know the command you want to say, click the triangle at the bottom of the speech feedback window and choose "Open Speech Commands window."
Every item in the Speech Commands window is a command. The Speakable Items commands are available from any application. Other commands may only be available if certain applications are open.
Sit about 21 inches in front of your computer's microphone. If you're using an external microphone, make sure it's correctly connected to your computer.
When there is minimal or no background noise and you're ready to speak a command, press the listening key and say your command in a calm voice.
Do not shout, yell, hesitate, or pause as you say the command. Ideally, when you are speaking you should see green bars in the sound level meter in the lower portion of the speech feedback window.
To have your computer acknowledge when it has recognized your spoken command, choose a sound from the "Play this sound" pop-up menu, or select the "Speak command acknowledgment" checkbox in Speech preferences.
