(en)Pidato Bell di hadapan American Association for the Advancement of Science di Boston pada 27 Agustus1880, menghadirkan fotopon. Dimuat sebagai "On the Production and Reproduction of Sound by Light" di American Journal of Sciences, Third Series, vol. XX, #118, Oktober 1880, hh. 305 - 324; dan sebagai "Selenium and the Photophone" di Nature, September 1880