How to turn on and use Mac speech commands

Has Siri gotten you accustomed to barking commands at electronics devices? Or has the absence of Siri in your life left you pining for a machine to command?

If you nodded in agreement to either of the above questions, and you own a Mac, did you know it has a built-in speech recognition tool? One that will speak back to you? Even tell you a terrible knock-knock joke?

If you'd like to begin conversing with your Mac, it is a simple process to enable speech recognition. Here's how:

Step 1: Go into System Preferences and choose Speech.

Step 2: Click Speech Recognition at the top (next to Text to Speech) and next to Speakable Items, click On.

Step 3: Click the Calibrate button and adjust the slider as you speak the phrases listed to get the volume level just right.

Step 4: Choose a voice for your Mac. Click Text to Speech at the top of the Speech window and select a name from the pull-down menu next to System Voice. Some are male (Alex, Junior, Ralph) and some are female (Agnes, Kathy, Victoria), while others are deranged (Deranged) or incomprehensible (Bubbles). You can also adjust how fast your Mac will speak by using the slider next to Speaking Rate.

Further, if you go back to the Speech Recognition window, you'll see two options next to Listening Method; you can choose whether your Mac will listen at all times or only when you hold down a key. The default key is Esc, but you can change it to another key or key combination by clicking the Change Key button next to the Listening Key header. I changed it from Esc because with speech enabled, I couldn't escape out of a screen capture, for example, using Command-Shift-4.

Also on the Speech Recognition window, at the bottom is a check box for Speak command acknowledgement. Check this box if you'd like your Mac to play a sound when it understands a command. I found it useful at first, when I was getting used to speaking to my Mac. I found that I was actually speaking too slowly, and when I used a more natural speaking tone and pace, my Mac recognized more of my commands.

With speech enabled, you'll see a small, circular microphone window. The microphone icon is grayed out and when you press your Listening Key(s), it turns black, letting you know your Mac has his or her ears on.

So, what sorts of commands does it recognize? For a list, click the small arrow at the bottom of the circular microphone window and choose Open Speech Commands window. Here you'll see commands grouped under Address Book, Speakable Items, and Application Switching.

I haven't found a speech command yet that I think I'd use with any regularity, but I do enjoy saying, "Mail to Mike Elliott" and having my Mac open up a Gmail window addressed to my brother. And under Speakable Items, I like the Move page to top or bottom commands when reading a long Web page (though, admittedly, swiping on the trackpad with three fingers is quicker). Also helpful were the app-switching and -quitting commands. And finally, you can command your Mac to tell you a joke, if you are in the mood for truly awful knock-knock jokes.

Are there speech commands you use with your Mac? If so, tell us your favorites in the comments below. And if you have a Windows 7 machine, here's how to use speech recognition on your computer, as well.