diff --git a/mosqito/sq_metrics/roughness/roughness_dw/_roughness_dw_main_calc.py b/mosqito/sq_metrics/roughness/roughness_dw/_roughness_dw_main_calc.py
index 7fe1e50e..1b23c16f 100644
--- a/mosqito/sq_metrics/roughness/roughness_dw/_roughness_dw_main_calc.py
+++ b/mosqito/sq_metrics/roughness/roughness_dw/_roughness_dw_main_calc.py
@@ -11,7 +11,6 @@
     _ear_filter_coeff,
 )
 from mosqito.utils.conversion import freq2bark, db2amp, amp2db, bark2freq
-import matplotlib.pyplot as plt
 
 def _roughness_dw_main_calc(spec, freq_axis, fs, gzi, hWeight):
     """
diff --git a/mosqito/sq_metrics/roughness/roughness_dw/roughness_dw.py b/mosqito/sq_metrics/roughness/roughness_dw/roughness_dw.py
index 8262dcab..5325b3b9 100644
--- a/mosqito/sq_metrics/roughness/roughness_dw/roughness_dw.py
+++ b/mosqito/sq_metrics/roughness/roughness_dw/roughness_dw.py
@@ -67,7 +67,10 @@ def roughness_dw(signal, fs=None, overlap=0.5, is_sdt_output=False):
     sig, time = time_segmentation(
         signal, fs, nperseg=nperseg, noverlap=noverlap, is_ecma=False
     )
-    nseg = sig.shape[1]
+    if len(sig.shape) == 1:
+        nseg = 1
+    else:
+        nseg = sig.shape[1]
 
     spec, _ = spectrum(sig, fs, nfft="default", window="blackman", db=False)