How is a higher level of the modulating signal represented in an FM signal?

In Frequency Modulation (FM), the amplitude (or loudness) of the input audio signal dictates how far the carrier frequency swings away from its center point. This shift from the center frequency is known as 'deviation.' Therefore, a louder audio signal results in a larger deviation of the carrier frequency. Conversely, the frequency (or pitch) of the input audio signal determines how rapidly this swing back and forth occurs. Because the information is encoded purely in the frequency variations, the transmitter's output power (carrier amplitude) remains completely constant. This constant amplitude is what makes FM so highly resistant to static noise.