diff --git a/panns.py b/panns.py
index 76635bb..e79c671 100644
--- a/panns.py
+++ b/panns.py
@@ -74,7 +74,8 @@ class Panns(NNOperator):
             resampler = torchaudio.transforms.Resample(sr, self.sample_rate, dtype=audio.dtype)
             audio = resampler(audio)
 
-        audio = audio[None, :]
+        if len(audio.shape) == 1:
+            audio = audio[None, :]
         clipwise_output, embedding = self.tagger.inference(audio)
 
         sorted_indexes = numpy.argsort(clipwise_output[0])[::-1]