Speaking and writing are two different methods of communication which today's society cannot be without. The mode a person chooses to communicate with depends on a number of things such as the situation, the person giving the information and the person receiving it. Speech is an impermanent method of communication as it cannot be recalled due to memory problems, therefore, it is less suitable for long and complex messages. It is a instantaneous and interactive method of a communication which is why it is a useful way of communicating emotions as well as the best method for conversation....
However, speaking from personal experience, I do have to add that the only time I talk on an instant messaging service is when the person who I am trying to contact is engaged on their phone line! It is the same with text messages; if they have there phone turned off, I text them so I know that as soon as they turn it on they will receive a message from me telling them what I needed them to know!

My personal favourite method of communication is speech; there is nothing better than a good conversation!