Good afternoon. If traditional glue and silicone inserts are used to protect the main elements of the smartphone, then a more complex technology is required for the speakers: physics comes to the rescue, and a very fine-mesh mesh created thanks to the effects of cohesion and surface tension, which does not allow water to pass through. Also, manufacturers often use a special waterproof and breathable fabric - a membrane - as a protective mesh. Similar material, for example under the GoreTex brand, can be found in hiking clothing.
There are rubber seals that do not let water through. The technology is the same. If you put a condom on your camera you can swim and take pictures.
Technologies requiring modernization, for example, or something that would make life easier for people.