How is the speed of sound affected by the nature of the sound wave?

• A. Affected by wavelength
• B. Affected by frequency
• C. Not affected
• D. Affected by amplitude

Answer: (C)

The speed of sound is determined by the medium itself, not by the specific sound wave traveling through it. In a given medium, how fast a pressure disturbance moves depends on the medium’s stiffness and density. Because of that, changing the wave’s frequency, wavelength, or amplitude doesn’t alter the speed in non-dispersive conditions. The relationship v = fλ shows that if the frequency changes, the wavelength changes inversely to keep the speed the same. Amplitude only affects how loud the sound is, not how quickly it travels. (Note: in some dispersive materials, speed can depend on frequency, but in ordinary sound in air and typical media, the speed is essentially independent of the wave’s nature.)