I transferred an XAVC S movie to my smartphone using "Send to Smartphone", but I cannot hear any sound when I play it on my smartphone.

Depending on the smartphone, it may not be possible to play transferred XAVC S movies properly. For example, you may not be able to play the movie smoothly, or there may be no sound. 

We recommend the following operations.

• Transfer a proxy movie to the smartphone and play it.

1. Select MENU → Camera Settings2 → Proxy Recording → On.
2. Select MENU → Network → Send to Smartphone Func. → Sending Target → Proxy Only or Proxy & Original.
3. Play the proxy movie transferred using Send to Smartphone Func. on your smartphone.

• Use the Movie Edit add-on smartphone app to export the movie and play it. 
   For details on the operating method, refer to the Movie Edit add-on support page.
  https://support.d-imaging.sony.co.jp/app/movieedit/l/index.php