Many toys/dolls have voice boxes. When you press a button they sing, or make a noise or have music.Aslong you change the batteries it must long last the voice box. But, sooner or later even if you change the batteries the voice box will stop working or the button will stop being useful. So around how long is the "life time" of a toy voice box? 3 years? 5 years? 10 years? 20 years?