Using sox I created a .flac file.
I'm able to "play" the file which yields the following output of which I can also hear the audio:
% ./play Clip1.flac

Clip1.flac:

File Size: 356k Bit Rate: 161k
Encoding: FLAC Info: Processed by SoX
Channels: 1 @ 16-bit
Samplerate: 16000Hz
Replaygain: off
Duration: 00:00:17.64

In:100% 00:00:17.64 [00:00:00.00] Out:847k [ -====|====- ] Hd:2.8 Clip:0
Done.

When I try to use the transcribe.py script on the same file, it returns an empty {} JSON output