Apple iPhone 4G - Manual (Page 45)

For best results:
Speak into the iPhone microphone as if you were making a phone call. You can also Â
use the microphone on your Bluetooth headset or compatible Bluetooth car kit.
Speak clearly and naturally.
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Say only iPhone commands and names, and numbers. Pause slightly between Â
commands.
Use full names.
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For more about using Voice Control, including information about using Voice Control
in different languages, go to support.apple.com/kb/HT3597.
Voice Control normally expects you to speak voice commands in the language that’s
set for iPhone (the setting in General > International > Language). Voice Control
settings let you change the language for speaking voice commands. Some languages
are available in different dialects or accents.
Change the language or country: In Settings, choose General > International >
Voice Control and tap the language or country.
Voice Control for the iPod app is always on, but for better security you can prevent
voice dialing when iPhone is locked.
Prevent voice dialing when iPhone is locked: In Settings, choose General > Passcode
Lock and turn Voice Dial off. Unlock iPhone to use voice dialing.
See “Voice Dialing” on page 61 and “Using Voice Control with iPod” on page 95.
45 Chapter 3 Basics