1. A method for receiving input on an electronic device, comprising: detecting audible sound generated by strokes of an at least one character written on a writing surface; identifying from the detected sound a stroke sequence comprising at least one stroke and a predefined sound signature defining either a straight stroke or a curved stroke or both; determining the at least one character written on the writing surface using a predetermined character mapping that associates a particular character of the at least one character written on the writing surface with a particular stroke sequence, wherein the predetermined character mapping identifies the particular character by determining whether the particular stroke sequence includes either the straight stroke or the curved stroke or both, and by counting the number of straight strokes and curved strokes in the particular stroke sequence; distinguishing characters having the same stroke sequence resulting from the character mapping by recognizing a direction of each stroke relative to one another using a pad having a textured surface having at least two textured patterns oriented in different directions; and outputting a string comprising the at least one character determined by the predetermined character mapping.