Sound waves create different pitches based on their frequency, which is the number of wave cycles that occur in one second, measured in hertz (Hz). Here’s how it works:

1. Frequency: Higher frequencies produce higher pitches, while lower frequencies create lower pitches. For example, a sound wave with a frequency of 440 Hz corresponds to the musical note A4, while a wave at 220 Hz corresponds to A3, one octave lower.

2. Wavelength: The frequency is inversely related to wavelength; higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.

3. Tension and Length: In musical instruments, factors like string tension and length (for strings) or the length of the air column (for wind instruments) affect the frequency of the sound produced. Tighter strings or shorter lengths produce higher pitches.

4. Amplitude: While amplitude affects the loudness of a sound, it does not influence pitch.

In summary, pitch is determined primarily by the frequency of the sound waves, with higher frequencies corresponding to higher pitches and lower frequencies corresponding to lower pitches.