Sound waves can stop traveling or become significantly attenuated due to several factors:
Absorption: Sound waves can be absorbed by materials they encounter during propagation. When sound waves encounter an absorbing medium, such as a soft material or a porous surface, the energy of the waves is converted into heat, leading to a decrease in the intensity of the sound. This absorption can eventually cause the sound waves to dissipate entirely.
Reflection: Sound waves can be reflected when they encounter a surface that is capable of reflecting sound. The reflection can occur at various angles, and the extent to which the sound waves are reflected depends on the properties of the surface. When sound waves are reflected, they change direction and travel in a different path. If the reflected sound waves do not reach the listener or encounter further reflection, the perception of sound from that source may cease.
Scattering: Sound waves can also scatter when they encounter small obstacles or irregularities in the propagation medium. Scattering causes the sound waves to change direction and disperse in different directions. This scattering effect can lead to a decrease in the overall intensity of the sound and make it less audible or discernible.
Attenuation: As sound waves propagate through a medium, they gradually lose energy due to the inherent resistance and friction within the medium. This phenomenon is called attenuation. The rate of attenuation depends on factors such as the distance traveled, the medium's properties (e.g., air, water), and the frequency of the sound waves. Over a sufficiently long distance, sound waves can become so attenuated that they are no longer perceptible.
It's important to note that while sound waves can weaken or stop traveling under certain conditions, they can still be influenced by factors like reverberation or refraction, which may cause them to continue or change their direction of propagation. The behavior of sound waves is complex and depends on various environmental and medium-specific factors.