On 10 May 1921 student members of the Radio Club at Union College, Schenectady, rigged up a wireless receiving station on a baby carriage with a small megaphone mounted under the hood. A sympathetic mother loaded in her baby, and a student wheeled the carriage into the city’s business district.
At the same time, a young woman at the club’s sending station on the college grounds began singing a lullaby. Her singing was reproduced by the receiver on the carriage as it moved all through the city, for over a mile. Those present reported that the baby was “as good as could be” from start to finish.
This according to “Very latest in wireless: Union College students find a universal lullaby for babies” (New York times, 11 May 1921, p.12), which was reprinted in Music, sound, and technology in America: A documentary history of early phonograph, cinema, and radio (Durham: Duke University Press, 2012).
A digitized reproduction of the original article is here. Below, a modern version of the carriage.