Abstract: A telephone is disclosed which includes a transducer and a controller. The transducer produces a sound having a level which varies as a function of the frequency and duty cycle of an excitation signal. The controller provides the excitation signal which has different frequencies, such as a coded melody. The controller varies the duty cycle so that the level of the sound from the transducer remains constant at the different frequencies. The telephone also includes a memory for storing values of the duty cycle corresponding to the different frequencies. These values allow the level of the sound to remain constant at the different frequencies. The controller codes the melody by storing in a table of the memory components of the melody, such as notes, silences, repetitions, the duration of each note or each silence, and a repetition number for melody components which are to be repeated. A time limit is also included in the table when the repetition number is infinite.