Final answer:
The medium through which sound travels affects its speed and transmission quality; sound waves travel faster through denser solids than less dense liquids or gases, and sound is transmitted more effectively in warmer conditions.
Step-by-step explanation:
The medium through which a sound wave travels greatly affects how fast and how well the sound is transmitted. Sound waves travel faster through mediums that are more dense because the particles are closer together, enabling the vibrations that constitute sound to be transmitted more easily. So, sound will travel faster and you will be able to perceive it for a longer period when it moves through solids, compared to liquids, and it will travel the slowest through gases. In the case of a stethoscope, direct contact with the body allows the sound to be more effectively transmitted than through the air because of the density and elasticity of the material the stethoscope is made from, which intensifies the sound when it reaches the eardrum.
Moreover, the temperature of the medium can affect the sound speed; warmer mediums increase the speed of sound because the particles have more kinetic energy and move faster. However, if the particles in a medium do not compress much or are less densely packed, the sound will not travel as quickly through the medium. Thus, for an extended perception of sound, the medium should ideally be solid and warm.