Describe an environment in which the sound of a ringing cell phone could not be transmitted, and explain why the ringing wouldn't be heard. Assume that the phone is working and that the cell signal has not been interrupted

In a vacuum

Explanation:

Sound is a type of mechanical waves. Mechanical waves are waves that propagate through the oscillation of the particles in a medium, which can be either gas, liquid or solid.

A sound wave in air, for instance, is simply produced by the oscillations of the air particles back and forth along the direction of motion of the wave.

Given this definition, it is clear that mechanical waves (and so, sound waves as well) cannot be transmitted if there is no medium: therefore, they cannot be transmitted in a vacuum. So, the sound of the ringing bell would not be present in a vacuum.