Yes, it is possible to transfer electrical energy into sound waves and vice versa without using antennas and generators of electromagnetic waves. There are various methods and devices that can achieve this conversion directly between electrical energy and sound waves.
One common device that converts electrical energy into sound waves is the loudspeaker or speaker. A loudspeaker consists of an electrical coil (voice coil) that interacts with a permanent magnet. When an electric current flows through the coil, it generates a magnetic field that interacts with the magnetic field of the permanent magnet. This interaction causes the voice coil to move back and forth, which in turn moves a diaphragm or cone attached to it. The movement of the diaphragm produces sound waves, thus converting electrical energy into sound energy.
Conversely, the process of converting sound waves into electrical energy is achieved through devices like microphones or transducers. A microphone consists of a diaphragm that vibrates in response to sound waves. These vibrations are then converted into electrical signals through various mechanisms, such as a coil moving within a magnetic field or a piezoelectric material generating electric charges in response to mechanical stress. The electrical signals produced by the microphone can be amplified and processed for various applications.
It's important to note that while these devices directly convert electrical energy into sound waves and vice versa, they still rely on electromagnetic principles at a microscopic level. The interaction between magnetic fields and electric currents is involved in the conversion process. However, these devices do not require antennas or generators of electromagnetic waves in the sense of radio frequency transmission or reception.