The same way you would when using any other headset (dial the number on the phone or use voice command).

没有人找你时，也可以按一下进行语音呼叫。 我们为你的手机带来了新的视野，重新定义了你对手机的期望！

youdao

Love a person is to dial the phone, suddenly do not know what to say, just want to hear the familiar voice, but really want to listen to the heart of a string!

爱一个人就是在拨通电话时，忽然不知道说什么好，原来只是想听听熟悉的声音，但真正想听的是心底的一根弦！

youdao

Once you dial, your VXML application should pick up, and let you know (in an unexciting mechanical voice) that "Things are working correctly!

拨号后，您的 VXML 应用程序应获取号码，并让您知道（用一种单调机械的声音）：“Things are working correctly!

youdao

Wax Bee is rechargeable and compatible with all Bluetooth enabled music and hands-free devices, and supports voice dial and redial functions.

ENGADGET: BeeWi's Ghost Bee Bluetooth headphones also stream music to your stereo (hands-on)

It also can be a rather multi-step affair to even make a call, since there's no home screen speed dial or voice recognition, and the phonebook can't be searched, only scrolled through.

ENGADGET: Apple iPhone review roundup Mobile

One of their current projects is the SmartButton, a wireless Bluetooth-enabled badge that connects to your phone and that you press when you want to call someone (you use the phone's voice recognition software to actually dial).

ENGADGET: Motorola's Bluetooth SmartButton