Until now all theories affirm that the sounds that occur under water cannot be transmitted to the air. However, they have published a theory that revokes this idea. According to this theory, the sound source emits two types of waves, some capable of crossing the surface of the water to extend it to the air and others, which are reflected on the surface. The airborne waves are of low frequency. These waves lose force with relative ease toward the surface, so it is only possible that the sound reaches the air if the sound transmitter is near the surface.