Hey there! Hello!
Sound travels through rubber at about 60 m/s. This is due to its low elastic properties. Elastic properties of materials mainly has to do with a material's ability to maintain its shape and avoid deforming as a result of a force being applied to it.
When comparing rubber to something much more rigid, like a metal, you can see why sounds travels much faster and farther through metal than rubber: metal has a higher rigidity and higher elastic properties, meaning that it will "spring back" much faster to its original position than rubber, giving less resistance to the noise.
Hope this helps you out! Feel free to ask me any additional questions if you have any. :-)