The question of “how many decibels is the Sun” is common, but it is rooted in a misunderstanding of how sound works in space. Decibels measure the intensity of sound, which is created by mechanical vibrations moving through a physical medium. The physics of the space between the Sun and Earth make it impossible for sound waves to travel the necessary distance, rendering a traditional decibel measurement meaningless. To understand the Sun’s actual output, one must first grasp why the near-vacuum of space prevents its transmission.
The Decibel Scale and Sound on Earth
Sound is defined as a mechanical wave that requires a medium—such as air, water, or solids—to propagate by creating alternating regions of high and low pressure. These pressure variations are what the human ear detects and interprets as noise. The intensity, or loudness, of this pressure is measured using the decibel (dB) scale, which is logarithmic.
This logarithmic nature means that a sound 10 times more powerful than the quietest audible sound (0 dB) is 10 dB. On Earth, a normal conversation registers around 60 dB, while the roar of a jet engine at takeoff reaches approximately 120 dB. The decibel scale provides a convenient way to quantify the vast range of sound pressure levels found in a dense, particle-filled environment like our atmosphere.
The Problem of the Vacuum
The fundamental reason the Sun cannot be measured in decibels at Earth is the near-perfect vacuum of space. Sound waves transmit energy by causing molecules in a medium to bump into one another, but the vast expanse between our planet and the Sun contains an insufficient number of particles for this process to occur. The lack of molecular density means there is no continuous medium to carry the pressure wave from the Sun’s surface to our atmosphere.
Therefore, the decibel level of the Sun’s sound waves reaching Earth is zero, because the traditional mechanism for sound propagation fails entirely. Although space is not an absolute vacuum, the density of gas and plasma is far too low to support the transmission of an audible pressure wave across 93 million miles.
Solar Emissions: What the Sun Actually Produces
Since the Sun does not produce sound that travels through space, its energy output is instead dominated by emissions that do not require a medium. The most familiar of these is electromagnetic radiation, which includes visible light, X-rays, and radio waves, all of which travel through a vacuum at the speed of light. The Sun also continuously emits a stream of charged particles called the solar wind, which is a plasma that interacts with Earth’s magnetic field.
The Sun is, however, filled with genuine sound waves, but these are trapped inside the star’s superheated plasma interior. This phenomenon, known as helioseismology, is the study of the Sun’s internal structure through its oscillations. These acoustic pressure waves are constantly generated by the turbulent motion of plasma near the surface, causing the entire star to vibrate like a giant bell.
These internal pressure waves, or p-modes, bounce off the Sun’s surface and curve back inward due to temperature and density changes within the star. Scientists on Earth can observe the subtle up-and-down movement of the Sun’s surface caused by these trapped waves and use the data to map the star’s interior.
When you hear recordings of the “Sun’s sound” from organizations like NASA, you are listening to a data translation. Scientists shift the extremely low-frequency solar vibrations or convert electromagnetic field data into the human audible range, giving the Sun a scientific “voice” that is built from data, not a direct recording of a traveling sound wave.