For convenience, might it be possible to include the latest sns files in the package and allow `sns_fname=None`, in which case the latest NY/AD sns would be used? I think we talked about it not being possible to infer the date form the recording exactly, right? But the sns does not change frequently, so a note in the docstring that for any files older than X it should be specified manually should be enough? Maybe you could even include older sns files and allow specification like `sns_fname="NY-2004"`?