Final answer:
The sound parameter determined only by the medium is propagation speed. It is influenced by the medium's properties like density and elastic modulus. The speed of sound is constant for a given medium under the same conditions, irrespective of the sound wave's frequency or amplitude.
Step-by-step explanation:
The sound parameter determined only by the medium is d) propagation speed. The speed of sound depends on the elastic and inertial properties of the medium, such as the density and the elastic modulus (usually described as stiffness for solids or bulk modulus for gases and liquids). Variables like temperature and pressure can also affect the speed of sound in various media, but not the other options provided (frequency, period, intensity), which are characteristics of the sound wave itself and can be influenced by the source of the sound or the wave's interactions with the environment.
For example, when considering a wave on a string (such as a guitar string), the frequency depends on factors like the tension and linear density of the string, as well as the length of the vibrating part of the string.
When speaking about a sound wave, amplitude will increase if you speak more loudly, affecting the intensity of the sound, but not the speed at which it travels through the air. The propagation speed of sound is consistent within the same medium, under the same conditions, no matter the frequency or amplitude of the wave.