You need to keep in mind certain things when speaking to people through the phone.

Firstly, when speaking to people through the phone, you have to keep it in mind that you may be distracting them.

Secondly, when speaking to people on the phone, you have to remember that you have no way of reading their body language.

Thirdly, when speaking to people on the phone, you have to remember that there may be others eavesdropping on the conversation. Actually, this is something you need to remember when speaking to people through all media: not just when speaking to people through the phone. This, for instance, is still something you would need to remember when speaking to people via www.gmail.com chat (that is, the Gmail.com instant messaging platform which is nowadays part of Gmail service). The fact that your conversation may be eavesdropped upon then means that you should be discreet. You should ask yourself whether what you are telling the person on the other hand is something you’d want a third party to be privy to.