Math in docstrings
## General

* pyfar version: 0.5.1

## Description

Formulas in the docstrings are not displayed correctly. Seems to be broken since Sphinx 5.3 (or similar)
diff --git a/docs/conf.py b/docs/conf.py
index 0ebb1b71..27dfad79 100755
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -38,7 +38,7 @@ extensions = [
     'sphinx.ext.napoleon',
     'sphinx.ext.autosummary',
     'matplotlib.sphinxext.plot_directive',
-    'sphinx.ext.imgmath',
+    'sphinx.ext.mathjax',
     'autodocsumm']
 
 # show tocs for classes and functions of modules using the autodocsumm
@@ -49,8 +49,6 @@ autodoc_default_options = {'autosummary': True}
 # package matplotlib.sphinxext.plot_directive
 plot_include_source = True
 
-imgmath_latex_preamble = r'\\usepackage{array}'
-
 # Add any paths that contain templates here, relative to this directory.
 # templates_path = ['_templates']
 
diff --git a/pyfar/dsp/dsp.py b/pyfar/dsp/dsp.py
index 8b77aa1c..a0fcc665 100644
--- a/pyfar/dsp/dsp.py
+++ b/pyfar/dsp/dsp.py
@@ -1366,7 +1366,7 @@ def find_impulse_response_start(
     """
     ir_squared = np.abs(impulse_response.time)**2
 
-    mask_start = np.int(0.9*impulse_response.n_samples)
+    mask_start = int(0.9*impulse_response.n_samples)
 
     mask = np.arange(mask_start, ir_squared.shape[-1])
     noise = np.mean(np.take(ir_squared, mask, axis=-1), axis=-1)
diff --git a/tests/test_dsp_normalize.py b/tests/test_dsp_normalize.py
index d4bf0ec9..1402a65d 100644
--- a/tests/test_dsp_normalize.py
+++ b/tests/test_dsp_normalize.py
@@ -44,11 +44,11 @@ def test_domains_normalization():
     time = pf.dsp.normalize(signal, domain="time")
     freq = pf.dsp.normalize(signal, domain="freq")
 
-    assert np.max(np.abs(time.time)) == 1
+    npt.assert_allclose(np.max(np.abs(time.time)), 1)
     assert np.max(np.abs(time.freq)) != 1
 
     assert np.max(np.abs(freq.time)) != 1
-    assert np.max(np.abs(freq.freq)) == 1
+    npt.assert_allclose(np.max(np.abs(freq.freq)), 1)
 
 
 @pytest.mark.parametrize('unit, limit1, limit2', (
['tests/test_dsp_normalize.py', 'docs/conf.py', 'pyfar/dsp/dsp.py']