An individual by the name of Martin Kroeger published several adverts for treatment of deafness in London’s newspapers, introducing a new treatment that would benefit or cure certain forms of middle-ear deafness. Evan Yellon, the writer of Surdus in Search of His Hearing (1906), a copy which is at the RNID Library on Grey’s Inn Road in London, documents his experiences in visiting Kroeger’s practice.

The Kroeger Light Cure Institute  located in Elizabeth Street, Eaton Square, had several rooms with dark and very heavy curtains enveloping them. For the course of an hour, Yellow was given a tour and full explanation of Kroeger’s methods, which combines three various applications: Light, Vibration, and Electricity  The treatment method, despite being very expensive and prolonged, could provide results.

The first, Light. Yellow is taken into a dark room with a couch and several lamps of “curious shapes” designed to pulsate powerful and concentrate rays of light. According to Kroeger, the apparatus mounted upon a beautifully finished adjustable stand was designed to give out light containing “enormous qualities of Ultra Violet Rays, which by means of a speculum are reflected into the meatus of the ear, and on to the tympanum membrane.” The rays aim to have a three-fold effect in treating deafness:

they first destroy any bacteria, or the cause of any growth, and secondly, they cause the blood to flow to the surface fo the illuminated parts; and thirdly, they improve the quality of that blood by increasing the number of red pigments in it, a matter of very great importance when a malignant growth is to be resisted or an unhealthy condition exists.

The lamps gave out no heat, as Yellow discovered, and was presumably safe to use on a person’s ear.

Kroeger then guides Yellow to the Vibration Room, with a very large and massive brass frame in the middle of the room, with a powerful electric motor suspended in the middle of the frame. The wall next to the frame was fitted with a switchboard. According to Kroeger, a patient would sit in the comfortable chair, upon which he would connect a “queer little instrument” to the motor. The instrument was the Vibrator, composed of an ebony handle on one end with a wire to connecting to the motor; there was an oval-shaped pad at the other end, fixed with a tiny engine that, when turned on, delivered a current.

The idea behind the Vibrator was to treat cases of dry middle ear catarrh, (deafness caused by the buildup of calcium in the small bones of the ear), by supplying small amounts of current to break the calcification and restore sound waves. Doing so would make the small bones once again “movable” and able to transmit liquids into the internal ear, thus restoring hearing.

The third and final part of Kroeger’s treatment was in the Electricity Room. There, the place was “literally bristle with wires, switches, and indicators,” with the wires connecting to a high couch in the middle of the room. High frequency currents of 200,000 volts were passed to the patient’s body, designed to strengthen and tone up the nervous system–or in the case of deafness, to “strengthen the auditory nerve”!

Two years after Yellow’s interview, Kroeger left the Light Care institute, wanting to specialize in aural and skin cases. He ended up devising various Electro-chemical ear treatments, including an Ear Bath, which applies electricity to the ear with stable electrodes soaked in warm water and medicinal properties. But, according to Yellow, Kroeger still favors the Vibrator.