1. A data input system comprising means for receiving an input speech signal representing a character, means for processing the received speech signal and for comparing the processed speech signal with a stored library of characters in order to allot a character from the library to the input speech signal; means for displaying the allotted character as a candidate character, and means responsive to another input from a user of the device to store the displayed character as part of a retrievable data stream, and wherein if the user decides that the displayed character does not correspond to the initial input speech signal, a repetition of the input speech signal by the user in the absence a selection input causes the processing and display means to display another candidate character from the stored library which is different from the previously displayed character, this process being repeatable until a selection input from the user selects a display character as a correct character.