What makes one sound louder than another?
The bigger the vibration (the more distance the string travels back and forth), the louder the sound. The smaller the vibration, the softer the sound.
And so, this vibration….
will sound louder than this vibration…
because the first vibration moves more air back and forth than the second vibration. The more air that is compressed, the higher the pressure, the more your ear drums move in response, and the louder your brain perceives the sound.