Hands free

基本解释

Another cool feature of this is the voice activation for hands free phones.
另外一个很酷的特色就是免提电话语音激活。
In a nation where most people still use public transportation to get around, commuters need to keep their hands free to hang from a subway strap or bus pole.
多数人出门还需要使用公共交通工具，这样人们就需要腾出手来扶地铁或者公交车的横梁。
It is hoped the break-through will be able to create safer hands free mobile phones to help the disabled and elderly and help out professionals in high pressured working environments.
他们希望利用这项技术为残疾人，行动不便的老年人，以及高压工作环境下的工作人员研制出更安全且不用双手的手机。

They also suggested taking measures to reduce exposure to the signals, like hands-free devices or texting.
So, I encourage you to do that the next time you have some free time on your hands, maybe at IAP or some time like that.
下次你有空余时间时,我鼓励你去看一看，也许在IAP或者什么时候。
麻省理工公开课 - 化学原理课程节选
" ...when all of God's children, black men and white men, Jews and Gentiles, Protestants and Catholics, will be able to join hands and sing in the words of the old Negro spiritual: Free at last! Free at last!

Equipped with a built in microphone, hands free phone conversations and multiple listener conference calls have never been easier.
ENGADGET: Edifier's iF335 Bluetooth speaker pumps up the volume for $99