Merge branch 'main' of https://github.com/NVIDIA/NeMo into main

Author: okuchaiev

nemo/collections/asr/parts/perturb.py

@@ -278,6 +278,7 @@ def __init__(self, manifest_path=None, rng=None, audio_tar_filepaths=None, shuff
         self._audiodataset = None
         self._tarred_audio = False
         self._shift_impulse = shift_impulse
+        self._data_iterator = None
 
         if audio_tar_filepaths:
             self._tarred_audio = True