[Python] ValueError: invalid literal for int() with base 10

Recorded with Pyaudio:

FORMAT = pyaudio.paInt16
CHANNELS = 1
RATE = 16000
CHUNK = 1024
rec = []

pyAudio.open(rate=RATE,
channels=CHANNELS,
format=FORMAT,
input=True,
output=True,
frames_per_buffer=CHUNK)

data = self._stream.read(CHUNK)
rec.append(data)
run(b’’.join(rec))

The error is in line:
result = deepspeechModel.stt(audio_buffer=audio)