In 1934, electronic engineer and inventor F.H. Leeuwrik built a speaking clock for the municipal telephone service of The Hague using optically recorded speech, looping on a large drum. The female voice was provided by the then 24-year-old school teacher Cor Hoogendam, hence the machine was nicknamed Tante Cor (Aunt Cor).Ik zal u doorverbinden, C.J. Wulffraat et al., in Honderd jaar telefoon, ed. J.H. Schuilenga et al., Staatsbedrijf der Posterijen, Telegrafie en Telefonie, 's-Gravenhage, 1981, p. 215
