MicrophoneArray.append(MicrophoneArray), do not crash when signal exists

CHANGELOG.rst

@@ -11,7 +11,11 @@ adheres to `Semantic Versioning <http://semver.org/spec/v2.0.0.html>`_.
 `Unreleased`_
 -------------
 
-Nothing yet
+Bugfix
+~~~~~~
+
+- Fixes MicrophoneArray.append(MicrophoneArray)
+  AttributeError: 'MicrophoneArray' object has no attribute 'shape'.
 
 `0.8.4`_ - 2025-05-19
 ---------------------

pyroomacoustics/beamforming.py

@@ -535,20 +535,23 @@ def append(self, locs):
             a `numpy.ndarray` with each column containing the coordinates of a
             microphone.
         """
+        n_new_mics = 0
         if isinstance(locs, MicrophoneArray):
             self.R = np.concatenate((self.R, locs.R), axis=1)
             self.directivity += locs.directivity
+            n_new_mics = locs.R.shape[1]
         else:
             self.R = np.concatenate((self.R, locs), axis=1)
             self.directivity += [None] * locs.shape[1]
+            n_new_mics = locs.shape[1]
 
         # in case there was already some signal recorded, just pad with zeros
         if self.signals is not None:
             self.signals = np.concatenate(
                 (
                     self.signals,
                     np.zeros(
-                        (locs.shape[1], self.signals.shape[1]), dtype=self.signals.dtype
+                        (n_new_mics, self.signals.shape[1]), dtype=self.signals.dtype
                     ),
                 ),
                 axis=0,

pyroomacoustics/tests/test_microphone_array.py

@@ -99,3 +99,11 @@ def test_microphone_array_append(shape1, shape2, with_dir, from_raw_locs):
 
     assert mic_array.nmic == shape1[1] + shape2[1]
     assert len(mic_array.directivity) == shape1[1] + shape2[1]
+
+
+def test_microphone_array_append_with_existing_signals():
+    mic_array = pra.MicrophoneArray(np.ones((3, 2)), fs=_FS)
+    mic_array.signals = np.random.randn(2, 1000)
+    new_mic_array = pra.MicrophoneArray(np.ones((3, 1)), fs=_FS)
+    mic_array.append(new_mic_array)
+    assert mic_array.nmic == 3