The pitch of a sound is primarily determined by the frequency. Frequency refers to the number of vibrations or cycles per second, measured in hertz (Hz). Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches.
The other options you mentioned relate to different aspects of sound:
- Decibel level is a measure of loudness or intensity, not pitch.
- Amplitude refers to the height of the sound wave and is associated with volume rather than pitch.
- The medium through which the sound travels can affect the speed of sound but does not directly determine the pitch.
So, the correct answer is the frequency.