There are a few different approaches researchers have taken in the past to understand how the brain processes language. One method used involves implanting electrodes directly into the brain, this is typically done for medical reasons. This approach focuses on how a person physically moves their mouth to speak. On the other hand, The Semantic Decoder works differently becuase Instead of looking at physical movements, it focuses on the ideas and thoughts a person is thinking or listening. And this can be done without needing surgery. The Semantic Decoder uses a brain scanning technic, which is non-invasive and doesn't require any special procedures.

This technology is not perfect, not yet. It doesn't capture every single word a person hears or tries to say. However, it does get main ideas or the gist of what an individual is expressing. It can get a few specific phrases right, but overall, it's more about getting the general idea. It is still being worked on to make it more proficient at capturing details more accurately. 

Yes, semantic decoders are typically safe for use. When utilized responsibly, with proper measures in place to address privacy, security, bias,and ethical concerns, semantic decoders can indeed be considered safe to use.

Yes, there is a possibility for privacy concerns, to combat this it's detrimental for developers to have strong privacy rules, and get permission from users before collecting or using their data,and be clear about how they handle and share user information.