Mountain Lion Dictation: You Talk and Your Mac Types
Mountain Lion is the first version of OS X to include Dictation, so you can now talk instead of type. It’s almost identical to the dictation feature found on the iPhone 4S and third-generation iPad.
First, make sure Dictation is enabled in the Dictation & Speech System Preference pane’s Dictation tab; if it’s set to Off, click the On button.
After it’s enabled, Dictation couldn’t be easier to use. First, click where you want your words to appear, and then choose Edit→Start Dictation, or press the Fn key twice in rapid succession.
If your keyboard doesn’t have an Fn key, click the Shortcut pop-up menu in the Dictation & Speech System Preference pane to change the shortcut one that works with your keyboard.
When you start dictation, a little microphone icon appears. The purple filling indicates the level (relative loudness) of your voice. Try to keep the purple near the middle; not too high and not too low.
When you see the microphone icon, start speaking. After you’ve dictated a few sentences, click Done and let your Mac catch up. When the words appear you can start dictation again. Repeat as necessary.
It might not be a bad idea to save your document after you speak a few sentences or paragraphs; if you don’t, the words you dictated since your last Save will be lost if the app or your Mac crashes.
You can insert punctuation by speaking its name, such as period or comma. You can also perform simple formatting by saying new line or new paragraph to add space between lines.
Here are a few more tips to help you get the best results when you dictate:
Speak in a normal voice at a moderate volume level. Try to keep the purple in the microphone icon about half-full (or half-empty if you’re a pessimist).
Avoid background noise. If you expect to use dictation in a noisy environment or a room with a lot of ambient echo, you should consider using a headset microphone.
The headset that comes with iPhones and iPod touches is compatible with many Mac models.
Be sure the microphone is not obstructed. Check your Mac’s User Guide for the location of your built-in microphone (if you have one).
Be sure the input volume of an external microphone is sufficient. If you’re using an external microphone and the purple meter doesn't respond to your voice, select the microphone in the Input pane of the Sound System Preference pane and adjust its input level (volume).
One last thing — Dictation requires an Internet connection. When you dictate text, what you say is sent to Apple’s servers to convert it to text.
Other information, such as your contacts, may also be sent to help your Mac understand what you’re saying. If that makes you uncomfortable, you probably shouldn’t use the Dictation feature.