The pulsars are very dense and rapidly rotating neutron stars with a strong magnetic field. Their rotational periods range from roughly milliseconds to seconds. They emit a radiation beam along their magnetic poles, which can be received as the beam crosses the Earth.
When radio waves received from pulsars are converted to sound waves, they are audible by our ears. The pulsars “sounds” used for this composition were provided by the Jodrell Bank Centre for Astrophysics:
jb.man.ac.uk/research/pulsar/Education/Sounds/
