A Universe of Sound
Every sound begins with a vibration. When those vibrations travel through the air, they can enter the human eardrum where they are eventually turned into electrical signals that our brain interprets as sound. These vibrations can come from many sources on Earth as well as those in our Solar System and even across our universe.
Sound travels in a wave and has its own distinct properties. One of these is frequency, which is the measurement of how many peaks (or troughs) of a wave pass a particular point over a certain period of time. Frequency is most often measured in the unit of the Hertz (Hz), which is the number per second. In general, humans can hear in the range of 20 to 20,000 Hz. An elephant can hear in the range below humans, while dogs and cats are sensitive to much higher-frequency sounds.
Natural phenomena such as weather, earthquakes, and even black holes can produce very low-frequency sounds. Humans have also harnessed sound for improvements in technology such as medical imaging. Researchers can take information about objects or processes in the natural world and convert that it into sound to learn more about it or to communicate it in a different way.
Here, we will explore how scientists are using NASA's Chandra X-ray Observatory and other instruments on the ground and in space to study the cosmos through sound. Whether it comes from vocal chords in our throats or the surface of the Sun, sound plays a valuable role in our understanding of the world and cosmos around us.