Why the Decoder yields `i16`?

Currently, `rodio::decoder::Decoder` yields `i16` as an item.  Therefore, there are some loss when playing music with higher bit depth, such as 24- or 32-bit signed WAV.  This may make some audio manias sad.  Is there a specific reason `i16` was chosen?  Why not, for example, `f32` or `f64`?