David E. Hughes a professor of music at St. Joseph's College in Bardstown, Kentucky. In his spare time he was also an physicist conducting experiments in the arenas of electricity and audio. He is the inventor the carbon microphone and the induction balance and was possibly the first to transmit and receive radio waves.
His bid for "first" was way back in 1878. This was almost a decade ahead of marconi. While experimenting, he noticed that his induction balance caused noise in the receiver of his homemade telephone. He had noticed a clicking noise in his home built telephone each time he worked used his induction balance. Fixing a loose contact in the circuit stopped the sound.
Hughes deduced that radio waves, electromagnetic, radiated emissions, were produced by the coil of wire in his induction balance and a spark jumping the gap was the point they radiated from. [spark gap transmitter?] To test this he rigged up a clockwork transmitter that emitted clicks. Then Hughes walked the streets of London with his telephone in hand listening for the clicking noises.
He demonstrated his discovery to the Royal Society in 1880 but was told it was merely induction. But in truth his induction balance was emitting a radiowave. He had little training in the area of mathmatics and was unable to meet his peers requests for scientific method and proofs.
It is speculated by some that marconi "borrowed" some of Hughs ideas. At the very least I think Hughes deserves credit for the first mobile telephone call.
On the up side, he did get credit for his invention of the Hughes-printer, the carbon Microphone, and in large part the telegraph. David E. Hughes was trained pianist and his approach was like a ball-type typewriter where each key caused the corresponding letter to be printed at a distant receiver. His telegraph design is the grandfather of the typewriter, the telex system and all computer keboards.
One of the originals is at the HT Museum in Zagreb