Despite the author's optimism, Harry Grindell Matthews' wireless telephone did not prove to be practical, and may have even been a hoax.
El Paso (Texas) Herald, June 17, 1912, page 12:
The  Electromagnetic  Voice

  The  Time  Is  Drawing  Near  When  We  Shall Speak  Around  the  World  as  Now  We  Speak  Across  the  Room.  
A STARTLING prophecy, made 15 years ago by professor Ayrton seems on the eve of fulfilment, through recent advances in wireless telegraphy and more particularly wireless telephony.
    Said the English physicist: "Although still far away, we are gradually coming within thinkable distance of a time when, if a person wants to call a friend, he knows not where, he will call in a loud electro-magnetic voice, heard by him who has the electro-magnetic ear, silent to him who has it not. 'Where are you?' he will ask. A small reply will come, 'I am at the bottom of a coal mine,' or 'crossing the Andes,' or 'in the middle of the Pacific' or, perhaps, in spite of all the calling, no reply will come, and the man will know that his friend is dead."
    About four years after that prophecy was made the world was ringing with the news of the transmission of wireless messages across hundreds of miles of sea. Soon they were sent half across the ocean; then all the way across. The electro-magnetic voice and the electro-magnetic ear had begun to enter into the domain of human consciousness. Everybody knows the subsequent history of wireless telegraphy. Now we read the daily news on a speeding ship in the midst of the Atlantic now. Ships in distress can call rescuers from hundreds, or even thousands, of miles away. The sinking ship may go down before aid can reach it, but at least it will not disappear and leave no token, as happened so often in the past.
Telephony  In  Its  Infancy.
   But the complete fulfilment of the prophecy has not yet arrived, although it seems to be fast approaching. Wireless telegraphy is an accomplished fact, simply needing further development, but wireless telephony, which will be a greater marvel, is still in its infancy. But it is growing with astonishing rapidity, if the reports of what has recently been done in England may be accepted. The "aerophone" of H. Grindell-Matthews transmits human speech over a distance of 12 miles. It is no longer a question of simply sending signals which have to be translated into intelligible languange, but the voice itself goes, and is heard with all its intonations by the recipient.
    Thus Prof. Ayrton's scientific dream is partly realized. The voice may at least be heard at the bottom of a coal mine, though it cannot yet reach the summit of the Andes, or the middle of the Pacific ocean.
First  Step  That  Counts.
    It is the first step that counts. Wireless telegraphy was at the beginning confined in its range to a few miles. But, with amazing swiftness, that range was extended, until now there is no recognized limit. There is reason to believe that wireless telephony will exhibit a similar capacity of expansion. The one implies the other. They are "sister arts." Laboratory experiments long ago demonstrated the possibility of transmitting speech without wire. It could be accomplished over small distances by electro-magnetic induction. An American inventor, A. F. Collins, showed its possibilities a few years ago here in New York. I myself was a witness of the transmission of telephonic messages, by Mr. Collins's method, between ferryboats crossing the North river. In some experiments he made the voice audible at a distance of three miles. Other experimenters have achieved a certain degree of success. But Mr. Grindell-Matthews appears to have outstripped them all. The difficulties are purely technical, arising mainly from the fact that while almost any series of electric waves will serve to send telegraphic signals, a particular form of wave, having the same "amplitude," "phase" and "frequency" as the vibration of the voice, must be employed for wireless telephony.
    The new aerophone is described as being astonishingly compact. The sender consists of a small box containing a battery, a motor and a transmitter, which anybody can carry about with him. The receiver is equally simple and compact. The one stands for the "electro-magnetic voice" imagined by Prof. Ayrton, the other for the "electro-magnetic ear."
    Everybody must rejoice at this news, but there is no reason to be astonished by it. It was inevitable. It had to come. We have at last got so close to some of nature's greatest secrets that the real wonder would be a failure to get into the very heart of them. They cease to be mysterious as soon as they are grasped. The steam engine was a wonder only while it was new; wireless telegraphy no longer astonishes anybody; in a little while wireless telephony--talking with our friends, transmitting our wishes and our orders by means of ethereal waves, hundreds of miles, as we now transmit them a few yards by means of air waves--may be so common a method of communication that nobody will see anything surprising in it. It simply means taking away the wires of the telephone and talking through space, just as we have discarded telegraph wires and begun to send signals, dots and dashes through the air.
Worked  Twelve  Years.
    It is patience as much as genius that accomplishes these things. It is said that Mr. Grindell-Matthews has worked unceasingly for 12 years on his invention. Now that success is in sight no doubt he will have many fellow laborers. Somebody may soon outstrip him, as he has outstripped others. Every invention implies a successor; every step in advance demands another. Wireless telephony is in sight--what next?