The two "reproducing mechanisms" referred to in this extract are Dr. Thaddeus Cahill's Telharmonium, and the Budapest Telefon Hirmondó. The full text of this testimony is available at Google books.
Congressional Copyright Hearings, December, 1906, page 83:
Memorandum  on  the  bill  to  secure  intellectual  property,  being  "A  bill  to  amend  and  consolidate  the  acts  respecting  copyrights"  (Senate  No.  6330;  House  No.  19853;  May  31,  1906).

By  R.  H.  BOWKER,  vice-president  American  Copyright  League.]

    Moreover, invention is now developing a series of reproducing mechanisms, such as Doctor Cahill's "telharmonicon," or dynamophone, in which musical compositions will be translated to the ear without the interposition even of a cylinder or disk sound record; and it seems a common-sense inference that the musical composer should have as full rights in this as in other forms of copying or reproducing his thought. Budapest is said to have not only a telephone "newspaper," but a system of reading novels and other works of literature to telephone subscribers, and if this should reach such proportions as substantially to reduce the sale of the printed copies of a new novel from which the author would receive benefit, it would also seem a common-sense inference that the same or an equivalent royalty should be paid him.