In 1916, as recounted in this article, Earl C. Hanson set up table-side radio receivers in neighbor's dining rooms, in order to serenade them with mealtime music. Hanson was also the inventor, in 1921, of the first vacuum-tube based hearing aid.
The Electrical Experimenter, June, 1916, page 84:
Wireless Music With Your Meals
By ALBERT MARPLE
There is a new "fad" in Southern California, the place where novelties grow over night like the proverbial mushroom. This time the "something new" comes in the form of phonograph concerts by wireless. Sometimes they come in at the noon hour, at others while dinner is being served and again perhaps in the quiet of the evening, while the family is gathered around the hearth. However, when they do occur they do so unannounced, this fact making them all the more welcome. This "music by wireless" idea is one of the most recent electrical inventions of Earl C. Hanson, a young California radio expert. In a word this new "fad" consists of phonograph music being transmitted by wireless from the home of the inventor to the dwellings of a number of friends and neighbors residing within a mile or so of the Hanson residence. This music is sent to all of the homes simultaneously and with no effort on the part of those at the receiving ends of the "line." To show that his invention was a "workable" one young Hanson gave a series of concerts recently and the work of the system was pronounced wonderful.
During the past several years Mr. Hanson has been working on a new type of wireless telephone and it is with the assistance of this apparatus which he has recently perfected to a high degree that these wireless concerts are made possible. The telephone shown in one of the illustrations accompanying this story is used as a central station, being located in the experimenting room of the Hanson residence. Upon the roof of his home this inventor has erected an elaborate aerial and this was used for transmitting, while the receiving stations are located, some within and some outside the homes selected for the concerts.
At the central station an ordinary hornless phonograph is placed upon a table along with the wireless telephone apparatus. The shutters at the front of the phonograph are removed and within the "horn" section one or more ordinary microphones are placed, these being connected by wire with a pair of binding posts on the telephone. A cable connects the telephone with the aerial upon the roof. When the phonograph is started the music is caught by the microphones and carried by wire to the wireless telephone instrument, which, after serving as an amplifier, continues it on its way to the aerial. After leaving the aerial the sound is caught by the various radio receiving station apparatus, which latter are connected by wire with ordinary telephone receivers, these being equipped with small megaphones, the work of which is to assist in increasing the volume of sound. An important feature about this wireless music transmission is that so far as can be ascertained the music heard at the receiving stations is equally as loud as is that furnished by the phonograph. The central operator has absolute control over the volume of sound furnished by this device, this depending entirely upon the amount of electrical energy employed.