Abstract: An apparatus for producing an audible sound to indicate the occurrence of an incoming telephone call on a cellular telephone. The apparatus has a first circuit for producing a first waveform having a first voltage and a first frequency. The apparatus also has a second circuit for producing a second waveform, the second circuit being operably connected to the first circuit, thereby receiving the first waveform. The second waveform has a second voltage and a second frequency wherein the second frequency is proportional to the first voltage of the first waveform. The apparatus also has an amplifier for amplifying the second waveform to produce an amplified waveform, the amplifier being operably connected to receive the second waveform. The apparatus also has a sound generator for producing an audible sound from the amplified waveform wherein the sound generator is operably connected to receive the amplified waveform.