Trump put the call through onto speaker phone.

特朗普接电话后开了免提。

I always use a speaker phone, so my hands are free to do something else.

我总是使用免提电话，所以我的手可以腾出时间做其他事情。

I also noticed that this helps when you are in loud situations like factories, or an environment where its very difficult to actually hear through your speaker phone or regular phone speaker.

我还注意到，当你在工厂等嘈杂的环境中时，这很有帮助，或者很难通过扬声器或普通手机扬声器真正听到的环境。

You can use it through a normal speaker, or you can put it on speaker phone which is also the preferred method, so that you can lay your phone down, and actually be coaxed through the actual emergency.

你可以通过普通扬声器使用它，或者你可以把它放在扬声器电话上，这也是首选方法，这样你就可以放下手机，在指导下度过实际的紧急情况。