diff --git a/nkululeko/feat_extract/feats_opensmile.py b/nkululeko/feat_extract/feats_opensmile.py
index 2289c81f..607b55a2 100644
--- a/nkululeko/feat_extract/feats_opensmile.py
+++ b/nkululeko/feat_extract/feats_opensmile.py
@@ -8,12 +8,12 @@
 
 
 class Opensmileset(Featureset):
-    def __init__(self, name, data_df):
+    def __init__(self, name, data_df, feats_type=None, config_file=None):
         super().__init__(name, data_df)
         self.featset = self.util.config_val("FEATS", "set", "eGeMAPSv02")
         try:
             self.feature_set = eval(f"opensmile.FeatureSet.{self.featset}")
-            #'eGeMAPSv02, ComParE_2016, GeMAPSv01a, eGeMAPSv01a':
+            # 'eGeMAPSv02, ComParE_2016, GeMAPSv01a, eGeMAPSv01a':
         except AttributeError:
             self.util.error(
                 f"something is wrong with feature set: {self.featset}"
diff --git a/nkululeko/feat_extract/feats_wavlm.py b/nkululeko/feat_extract/feats_wavlm.py
index 03973c70..748791e1 100644
--- a/nkululeko/feat_extract/feats_wavlm.py
+++ b/nkululeko/feat_extract/feats_wavlm.py
@@ -59,10 +59,7 @@ def extract(self):
                     frame_offset=int(start.total_seconds() * 16000),
                     num_frames=int((end - start).total_seconds() * 16000),
                 )
-                if sampling_rate != 16000:
-                    self.util.error(
-                        f"sampling rate should be 16000 but is {sampling_rate}"
-                    )
+                assert sampling_rate == 16000, f"sampling rate should be 16000 but is {sampling_rate}"
                 emb = self.get_embeddings(signal, sampling_rate, file)
                 emb_series.iloc[idx] = emb
             self.df = pd.DataFrame(emb_series.values.tolist(), index=self.data_df.index)
diff --git a/nkululeko/feature_extractor.py b/nkululeko/feature_extractor.py
index a5f8f5bf..468dc5ea 100644
--- a/nkululeko/feature_extractor.py
+++ b/nkululeko/feature_extractor.py
@@ -39,10 +39,12 @@ def extract(self):
         self.feats = pd.DataFrame()
         for feats_type in self.feats_types:
             store_name = f"{self.data_name}_{feats_type}"
-            self.feat_extractor = self._get_feat_extractor(store_name, feats_type)
+            self.feat_extractor = self._get_feat_extractor(
+                store_name, feats_type)
             self.feat_extractor.extract()
             self.feat_extractor.filter()
-            self.feats = pd.concat([self.feats, self.feat_extractor.df], axis=1)
+            self.feats = pd.concat(
+                [self.feats, self.feat_extractor.df], axis=1)
         return self.feats
 
     def extract_sample(self, signal, sr):
@@ -53,14 +55,14 @@ def _get_feat_extractor(self, store_name, feats_type):
         if feat_extractor_class is None:
             self.util.error(f"unknown feats_type: {feats_type}")
         return feat_extractor_class(
-            f"{store_name}_{self.feats_designation}", self.data_df
+            f"{store_name}_{self.feats_designation}", self.data_df, feats_type
         )
 
     def _get_feat_extractor_class(self, feats_type):
         if feats_type == "os":
             from nkululeko.feat_extract.feats_opensmile import Opensmileset
-
             return Opensmileset
+
         elif feats_type == "spectra":
             from nkululeko.feat_extract.feats_spectra import Spectraloader
 
@@ -69,8 +71,10 @@ def _get_feat_extractor_class(self, feats_type):
             from nkululeko.feat_extract.feats_trill import TRILLset
 
             return TRILLset
-        elif feats_type.startswith(("wav2vec", "hubert", "wavlm", "spkrec")):
+        elif feats_type.startswith(
+                ("wav2vec", "hubert", "wavlm", "spkrec", "whisper")):
             return self._get_feat_extractor_by_prefix(feats_type)
+
         elif feats_type in (
             "audmodel",
             "auddim",
@@ -89,16 +93,18 @@ def _get_feat_extractor_class(self, feats_type):
             return None
 
     def _get_feat_extractor_by_prefix(self, feats_type):
-        prefix, _, ext = feats_type.partition("_")
+        prefix, _, ext = feats_type.partition("-")
         from importlib import import_module
 
-        module = import_module(f"nkululeko.feat_extract.feats_{prefix.lower()}")
-        class_name = f"{prefix.capitalize()}{ext.capitalize()}set"
+        module = import_module(
+            f"nkululeko.feat_extract.feats_{prefix.lower()}")
+        class_name = f"{prefix.capitalize()}"
         return getattr(module, class_name)
 
     def _get_feat_extractor_by_name(self, feats_type):
         from importlib import import_module
 
-        module = import_module(f"nkululeko.feat_extract.feats_{feats_type.lower()}")
+        module = import_module(
+            f"nkululeko.feat_extract.feats_{feats_type.lower()}")
         class_name = f"{feats_type.capitalize()}Set"
         return getattr(module, class_name)