Sound waves can travel through a medium (such as air, water, or solid objects) and can reflect or diffract around obstacles, allowing them to be heard even when there is no direct path to the source of the sound.
When sound waves encounter an obstacle, they can either reflect or diffract. Reflection occurs when sound waves bounce off a surface and return in the direction they came from. Diffracton occurs when sound waves bend around an obstacle and continue in a different direction. This allows sound waves to travel around corners and through small openings.
For example, if someone is talking behind a wall, the sound waves they produce can diffract around the wall and reach your ears, allowing you to hear them. Similarly, when you hear an echo, it is because sound waves have reflected off a surface and reached your ears.
In some cases, sound waves can even travel through solid objects. This is known as vibration or bone conduction. For example, when you hear your own voice or a piece of music through a set of headphones, the sound waves are transmitted through the headphones and vibrate the bones in your ear, which sends signals to your brain that you perceive as sound.
In summary, sound waves can travel through a medium and reflect or diffract around obstacles, allowing them to be heard even when there is no direct path to the source of the sound.