From 6aa6766457f00bb3eae1b3cddbd07ed4d0b24748 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 15:48:54 +0100
Subject: [PATCH 01/16] refactor Eyring reverberation time calculation

- update input variable names
- extend docstring
- update tests
---
 pyrato/parametric.py            | 70 ++++++++++++++++++++++-----------
 tests/test_parametric_eyring.py | 10 ++---
 2 files changed, 51 insertions(+), 29 deletions(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index cc00a3ff..21609b79 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -214,46 +214,70 @@ def mean_free_path(
     return 4 * volume / surface_area
 
 
-def reverberation_time_eyring(volume,surface,mean_alpha):
+def reverberation_time_eyring(
+        volume, surface_area, mean_absorption, speed_of_sound=343.4,
+    ):
     r"""
-    function which calculates reverberation time in rooms as
-    defined by Carl F. Eyring.
+    Calculate the reverberation time in rooms as defined by Carl Eyring.
+
+    The reverberation time is calculated according to Ref. [#]_ as
 
     .. math::
-        T_{60} = -0.161 \frac{\text{volume}}{\text{surface} \cdot
-            \ln(1 - \text{mean\_alpha})}
+        T_{60} = \frac{24 \cdot \ln(10)}{c}
+        \cdot \frac{V}{S \ln(1 - \tilde{\alpha})}
+
+    where :math:`V` is the room volume, :math:`S` is the total surface area
+    of the room, :math:`\tilde{\alpha}` is the average absorption coefficient
+    of the room surfaces, and :math:`c` is the speed of sound.
 
     Parameters
     ----------
-    volume : float, np.ndarray
-        Room volume in m3
-    surface : float, np.ndarray
-        Surface areas of all surfaces in the room in m2
-    mean_alpha : float, np.ndarray
-        Average absorption coefficient of room surfaces
+    volume : float
+        Room volume in :math:`\mathrm{m}^3`
+    surface : float
+        Total surface area of the room in :math:`\mathrm{m}^2`
+    mean_absorption : float, numpy.ndarray
+        Average absorption coefficient of room surfaces between 0 and 1. If
+        an array is passed, the reverberation time is calculated for each value
+        in the array.
+    speed_of_sound : float, numpy.ndarray
+        Speed of sound in m/s. Default is 343.4 m/s, which corresponds to the
+        speed of sound in air at 20 °C.
 
     Returns
     -------
-    reverberation_time_eyring: double
-         Eyring reverberation time in s
+    float, numpy.ndarray
+        Reverberation time in seconds. The shape matches the shape of the input
+        variable `mean_absorption`.
+
+    Examples
+    --------
+
+    >>> from pyrato.parametric import reverberation_time_eyring
+    >>> import numpy as np
+    >>> volume = 64
+    >>> surface_area = 96
+    >>> mean_absorption = [0.1, 0.3, 0.4]
+    >>> reverb_time = reverberation_time_eyring(
+    >>>     volume, surface_area, mean_absorption)
+    >>> np.round(reverb_time, 2)
 
     References
     ----------
-    .. [#] Eyring, C.F., 1930. Reverberation time in “dead” rooms. The Journal
-    of the Acoustical Society of America, 1(2A_Supplement), pp.168-168.
+    .. [#] Eyring, C.F., 1930. Reverberation time in "dead" rooms. The Journal
+           of the Acoustical Society of America, 1(2A_Supplement), pp.168-168.
 
     """
-
-    if volume <= 0:
+    mean_absorption = np.asarray(mean_absorption)
+    if np.any(volume) <= 0:
         raise ValueError("Volume should be larger than 0")
-    if surface <= 0:
+    if np.any(surface_area) <= 0:
         raise ValueError("Surface should be larger than 0")
-    if mean_alpha <0 or mean_alpha >1:
-        raise ValueError("mean_alpha should be between 0 and 1")
-
-    T60 = -0.161 * (volume / (surface * np.log(1 - mean_alpha)))
+    if np.any(mean_absorption < 0) or np.any(mean_absorption > 1):
+        raise ValueError("mean_absorption should be between 0 and 1")
 
-    return T60
+    factor = 24 * np.log(10) / speed_of_sound
+    return -factor * (volume / (surface_area * np.log(1 - mean_absorption)))
 
 
 def calculate_sabine_reverberation_time(surfaces, alphas, volume):
diff --git a/tests/test_parametric_eyring.py b/tests/test_parametric_eyring.py
index 757a3c2e..f9967faa 100644
--- a/tests/test_parametric_eyring.py
+++ b/tests/test_parametric_eyring.py
@@ -7,20 +7,18 @@ def test_analytic_Eyring():
     volume = 64
     surface = 96
     mean_alpha = 0.2
-    reverb_test = reverberation_time_eyring(volume,surface,mean_alpha)
+    reverb_test = reverberation_time_eyring(volume, surface, mean_alpha)
     npt.assert_allclose(reverb_test, 0.481, rtol=1e-3)
 
 @pytest.mark.parametrize("volume, surface", [(0, -2), (-1, 0)])
 def test_input_geometry_Eyring(volume, surface):
     mean_alpha = 0.2
     with pytest.raises(ValueError, match="should be larger than 0"):
-        reverberation_time_eyring(volume,surface,mean_alpha)
+        reverberation_time_eyring(volume, surface, mean_alpha)
 
 @pytest.mark.parametrize("mean_alpha", [-1, 2])
 def test_input_alpha_Eyring(mean_alpha):
     volume = 64
     surface = 96
-    with pytest.raises(
-        ValueError, match="mean_alpha should be between 0 and 1"
-    ):
-        reverberation_time_eyring(volume,surface,mean_alpha)
+    with pytest.raises(ValueError, match="should be between 0 and 1"):
+        reverberation_time_eyring(volume, surface, mean_alpha)

From 49050488e63c45b0d766e756210899ee10d6e669 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 16:17:55 +0100
Subject: [PATCH 02/16] - Add type hints - formatting and linting fixes

---
 pyrato/parametric.py            | 12 +++++++-----
 tests/test_parametric_eyring.py |  4 ++--
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 21609b79..1978d7cd 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -215,7 +215,10 @@ def mean_free_path(
 
 
 def reverberation_time_eyring(
-        volume, surface_area, mean_absorption, speed_of_sound=343.4,
+        volume: float,
+        surface_area: float,
+        mean_absorption: np.typing.NDArray[float],
+        speed_of_sound: float = 343.4,
     ):
     r"""
     Calculate the reverberation time in rooms as defined by Carl Eyring.
@@ -234,13 +237,13 @@ def reverberation_time_eyring(
     ----------
     volume : float
         Room volume in :math:`\mathrm{m}^3`
-    surface : float
+    surface_area : float
         Total surface area of the room in :math:`\mathrm{m}^2`
     mean_absorption : float, numpy.ndarray
         Average absorption coefficient of room surfaces between 0 and 1. If
         an array is passed, the reverberation time is calculated for each value
         in the array.
-    speed_of_sound : float, numpy.ndarray
+    speed_of_sound : float
         Speed of sound in m/s. Default is 343.4 m/s, which corresponds to the
         speed of sound in air at 20 °C.
 
@@ -252,7 +255,6 @@ def reverberation_time_eyring(
 
     Examples
     --------
-
     >>> from pyrato.parametric import reverberation_time_eyring
     >>> import numpy as np
     >>> volume = 64
@@ -272,7 +274,7 @@ def reverberation_time_eyring(
     if np.any(volume) <= 0:
         raise ValueError("Volume should be larger than 0")
     if np.any(surface_area) <= 0:
-        raise ValueError("Surface should be larger than 0")
+        raise ValueError("Surface area should be larger than 0")
     if np.any(mean_absorption < 0) or np.any(mean_absorption > 1):
         raise ValueError("mean_absorption should be between 0 and 1")
 
diff --git a/tests/test_parametric_eyring.py b/tests/test_parametric_eyring.py
index f9967faa..6cab4698 100644
--- a/tests/test_parametric_eyring.py
+++ b/tests/test_parametric_eyring.py
@@ -1,4 +1,4 @@
-"""Tests for Eyring's equation"""
+"""Tests for Eyring's equation."""
 import numpy.testing as npt
 import pytest
 from pyrato.parametric import reverberation_time_eyring
@@ -10,7 +10,7 @@ def test_analytic_Eyring():
     reverb_test = reverberation_time_eyring(volume, surface, mean_alpha)
     npt.assert_allclose(reverb_test, 0.481, rtol=1e-3)
 
-@pytest.mark.parametrize("volume, surface", [(0, -2), (-1, 0)])
+@pytest.mark.parametrize(("volume", "surface"), [(0, -2), (-1, 0)])
 def test_input_geometry_Eyring(volume, surface):
     mean_alpha = 0.2
     with pytest.raises(ValueError, match="should be larger than 0"):

From 10a3ff4f68ea6f237d8c84b8ad57221dbec803f0 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 16:19:12 +0100
Subject: [PATCH 03/16] improve grouping of input checks

---
 pyrato/parametric.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 1978d7cd..abf4e37a 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -270,11 +270,12 @@ def reverberation_time_eyring(
            of the Acoustical Society of America, 1(2A_Supplement), pp.168-168.
 
     """
-    mean_absorption = np.asarray(mean_absorption)
     if np.any(volume) <= 0:
         raise ValueError("Volume should be larger than 0")
     if np.any(surface_area) <= 0:
         raise ValueError("Surface area should be larger than 0")
+
+    mean_absorption = np.asarray(mean_absorption)
     if np.any(mean_absorption < 0) or np.any(mean_absorption > 1):
         raise ValueError("mean_absorption should be between 0 and 1")
 

From a75b430c4c02cc482a3d463a4cfb89eac8925157 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <mberz@users.noreply.github.com>
Date: Mon, 16 Feb 2026 17:00:06 +0100
Subject: [PATCH 04/16] Add return in example

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
---
 pyrato/parametric.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index abf4e37a..92375c6a 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -263,7 +263,7 @@ def reverberation_time_eyring(
     >>> reverb_time = reverberation_time_eyring(
     >>>     volume, surface_area, mean_absorption)
     >>> np.round(reverb_time, 2)
-
+    array([1.02, 0.3 , 0.21])
     References
     ----------
     .. [#] Eyring, C.F., 1930. Reverberation time in "dead" rooms. The Journal

From 1a788586adcec45fab6044f8edf618d5533896ef Mon Sep 17 00:00:00 2001
From: Marco Berzborn <mberz@users.noreply.github.com>
Date: Mon, 16 Feb 2026 17:00:25 +0100
Subject: [PATCH 05/16] formatting example

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
---
 pyrato/parametric.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 92375c6a..75bde2ce 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -261,7 +261,7 @@ def reverberation_time_eyring(
     >>> surface_area = 96
     >>> mean_absorption = [0.1, 0.3, 0.4]
     >>> reverb_time = reverberation_time_eyring(
-    >>>     volume, surface_area, mean_absorption)
+    ...     volume, surface_area, mean_absorption)
     >>> np.round(reverb_time, 2)
     array([1.02, 0.3 , 0.21])
     References

From 58699116036ee1beb4bd9c476b477c8459349729 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:11:56 +0100
Subject: [PATCH 06/16] update typing

---
 pyrato/parametric.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 75bde2ce..42cfaa75 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -4,6 +4,7 @@
 such as Sabine's theory of sound in rooms.
 """
 import numpy as np
+from typing import Union
 
 def calculate_speed_of_sound(temperature):
     r"""Calculate the speed of sound in air depending on the temperature.
@@ -217,7 +218,7 @@ def mean_free_path(
 def reverberation_time_eyring(
         volume: float,
         surface_area: float,
-        mean_absorption: np.typing.NDArray[float],
+        mean_absorption: Union[float, np.typing.NDArray[float]],
         speed_of_sound: float = 343.4,
     ):
     r"""

From f2d1a3293de8e10bbc66920396373e71754b9626 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:12:08 +0100
Subject: [PATCH 07/16] fix obsolete use of np.any

---
 pyrato/parametric.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 42cfaa75..274de6de 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -271,9 +271,9 @@ def reverberation_time_eyring(
            of the Acoustical Society of America, 1(2A_Supplement), pp.168-168.
 
     """
-    if np.any(volume) <= 0:
+    if volume <= 0:
         raise ValueError("Volume should be larger than 0")
-    if np.any(surface_area) <= 0:
+    if surface_area <= 0:
         raise ValueError("Surface area should be larger than 0")
 
     mean_absorption = np.asarray(mean_absorption)

From 10babb206aa08473bceead6aa11033fd369dd563 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:12:37 +0100
Subject: [PATCH 08/16] update tests & explicitly include edge cases for
 absorption

---
 pyrato/parametric.py            | 10 +++++++++-
 tests/test_parametric_eyring.py | 34 ++++++++++++++++++++-------------
 2 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 274de6de..990889f4 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -281,7 +281,15 @@ def reverberation_time_eyring(
         raise ValueError("mean_absorption should be between 0 and 1")
 
     factor = 24 * np.log(10) / speed_of_sound
-    return -factor * (volume / (surface_area * np.log(1 - mean_absorption)))
+
+    reverberation_time = -factor * (
+        volume/(surface_area * np.log(1 - mean_absorption)))
+
+    mask = np.isclose(mean_absorption, 0, atol=1e-10, rtol=1e-10)
+
+    reverberation_time = np.where(mask, np.inf, reverberation_time)
+
+    return reverberation_time
 
 
 def calculate_sabine_reverberation_time(surfaces, alphas, volume):
diff --git a/tests/test_parametric_eyring.py b/tests/test_parametric_eyring.py
index 6cab4698..b562fb26 100644
--- a/tests/test_parametric_eyring.py
+++ b/tests/test_parametric_eyring.py
@@ -2,23 +2,31 @@
 import numpy.testing as npt
 import pytest
 from pyrato.parametric import reverberation_time_eyring
+import numpy as np
 
-def test_analytic_Eyring():
+@pytest.mark.parametrize(
+        ("mean_absorption", "expected"),
+        [
+            ([0.2, 0.2], [0.481, 0.481]),
+            (1, 0),
+            (0, np.inf),
+            ([0, 1, 0], [np.inf, 0, np.inf]),
+        ])
+def test_analytic_Eyring(mean_absorption, expected):
     volume = 64
-    surface = 96
-    mean_alpha = 0.2
-    reverb_test = reverberation_time_eyring(volume, surface, mean_alpha)
-    npt.assert_allclose(reverb_test, 0.481, rtol=1e-3)
+    surface_area = 96
+    reverb_test = reverberation_time_eyring(volume, surface_area, mean_absorption)
+    npt.assert_allclose(reverb_test, expected, rtol=1e-3)
 
-@pytest.mark.parametrize(("volume", "surface"), [(0, -2), (-1, 0)])
-def test_input_geometry_Eyring(volume, surface):
-    mean_alpha = 0.2
+@pytest.mark.parametrize(("volume", "surface_area"), [(0, -2), (-1, 0)])
+def test_input_geometry_Eyring(volume, surface_area):
+    mean_absorption = 0.2
     with pytest.raises(ValueError, match="should be larger than 0"):
-        reverberation_time_eyring(volume, surface, mean_alpha)
+        reverberation_time_eyring(volume, surface_area, mean_absorption)
 
-@pytest.mark.parametrize("mean_alpha", [-1, 2])
-def test_input_alpha_Eyring(mean_alpha):
+@pytest.mark.parametrize("mean_absorption", [-1, 2])
+def test_input_absorption_Eyring(mean_absorption):
     volume = 64
-    surface = 96
+    surface_area = 96
     with pytest.raises(ValueError, match="should be between 0 and 1"):
-        reverberation_time_eyring(volume, surface, mean_alpha)
+        reverberation_time_eyring(volume, surface_area, mean_absorption)

From e1517d1627d9d04e555a6477fb15e44a7c284448 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:39:33 +0100
Subject: [PATCH 09/16] Add check speed of sound negative

---
 pyrato/parametric.py            | 2 ++
 tests/test_parametric_eyring.py | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 990889f4..dd9d4f85 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -271,6 +271,8 @@ def reverberation_time_eyring(
            of the Acoustical Society of America, 1(2A_Supplement), pp.168-168.
 
     """
+    if speed_of_sound <= 0:
+        raise ValueError("Speed of sound should be larger than 0")
     if volume <= 0:
         raise ValueError("Volume should be larger than 0")
     if surface_area <= 0:
diff --git a/tests/test_parametric_eyring.py b/tests/test_parametric_eyring.py
index b562fb26..c8b42df4 100644
--- a/tests/test_parametric_eyring.py
+++ b/tests/test_parametric_eyring.py
@@ -30,3 +30,12 @@ def test_input_absorption_Eyring(mean_absorption):
     surface_area = 96
     with pytest.raises(ValueError, match="should be between 0 and 1"):
         reverberation_time_eyring(volume, surface_area, mean_absorption)
+
+def test_error_speed_of_sound_Eyring():
+    volume = 64
+    surface_area = 96
+    mean_absorption = 0.2
+    with pytest.raises(ValueError, match="should be larger than 0"):
+        reverberation_time_eyring(
+            volume, surface_area, mean_absorption,
+            speed_of_sound=-1)

From ca62a039de4402ea5e4e28fb0d5b57d80d7c8625 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:39:49 +0100
Subject: [PATCH 10/16] more compact format

---
 pyrato/parametric.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index dd9d4f85..3ecfc048 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -287,9 +287,10 @@ def reverberation_time_eyring(
     reverberation_time = -factor * (
         volume/(surface_area * np.log(1 - mean_absorption)))
 
-    mask = np.isclose(mean_absorption, 0, atol=1e-10, rtol=1e-10)
-
-    reverberation_time = np.where(mask, np.inf, reverberation_time)
+    reverberation_time = np.where(
+        np.isclose(mean_absorption, 0, atol=1e-10, rtol=1e-10),
+        np.inf,
+        reverberation_time)
 
     return reverberation_time
 

From 9d6b8a3f29aac86a6dbebad874929c243951a7b1 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:40:21 +0100
Subject: [PATCH 11/16] docstring format

---
 pyrato/parametric.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 3ecfc048..f335dde4 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -264,7 +264,8 @@ def reverberation_time_eyring(
     >>> reverb_time = reverberation_time_eyring(
     ...     volume, surface_area, mean_absorption)
     >>> np.round(reverb_time, 2)
-    array([1.02, 0.3 , 0.21])
+        array([1.02, 0.3 , 0.21])
+
     References
     ----------
     .. [#] Eyring, C.F., 1930. Reverberation time in "dead" rooms. The Journal

From 7784fc6bf1d52f509fdfb0727a22a61e4b9d328f Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:44:24 +0100
Subject: [PATCH 12/16] formatting

---
 pyrato/parametric.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index f335dde4..6f18eb9c 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -264,7 +264,7 @@ def reverberation_time_eyring(
     >>> reverb_time = reverberation_time_eyring(
     ...     volume, surface_area, mean_absorption)
     >>> np.round(reverb_time, 2)
-        array([1.02, 0.3 , 0.21])
+    ... array([1.02, 0.3 , 0.21])
 
     References
     ----------

From d242042801045da7dda820728c692bb010a44ef6 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:44:24 +0100
Subject: [PATCH 13/16] formatting

---
 tests/test_parametric_eyring.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/test_parametric_eyring.py b/tests/test_parametric_eyring.py
index c8b42df4..6a8936c9 100644
--- a/tests/test_parametric_eyring.py
+++ b/tests/test_parametric_eyring.py
@@ -15,7 +15,8 @@
 def test_analytic_Eyring(mean_absorption, expected):
     volume = 64
     surface_area = 96
-    reverb_test = reverberation_time_eyring(volume, surface_area, mean_absorption)
+    reverb_test = reverberation_time_eyring(
+        volume, surface_area, mean_absorption)
     npt.assert_allclose(reverb_test, expected, rtol=1e-3)
 
 @pytest.mark.parametrize(("volume", "surface_area"), [(0, -2), (-1, 0)])

From e472cacca0239cdfd356495197d667e7edce77dc Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:50:43 +0100
Subject: [PATCH 14/16] suppress warnings for divide by zero which are
 explicitly handled below

---
 pyrato/parametric.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 6f18eb9c..f6cc7028 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -285,8 +285,9 @@ def reverberation_time_eyring(
 
     factor = 24 * np.log(10) / speed_of_sound
 
-    reverberation_time = -factor * (
-        volume/(surface_area * np.log(1 - mean_absorption)))
+    with np.errstate(divide='ignore'):
+        reverberation_time = -factor * (
+            volume/(surface_area * np.log(1 - mean_absorption)))
 
     reverberation_time = np.where(
         np.isclose(mean_absorption, 0, atol=1e-10, rtol=1e-10),

From d4d603c528d0432ae7af532344316a9bff83635e Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Mon, 16 Feb 2026 17:54:24 +0100
Subject: [PATCH 15/16] docstring and type hinting update

---
 pyrato/parametric.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index f6cc7028..72f98888 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -220,14 +220,14 @@ def reverberation_time_eyring(
         surface_area: float,
         mean_absorption: Union[float, np.typing.NDArray[float]],
         speed_of_sound: float = 343.4,
-    ):
+    ) -> np.typing.NDArray[float]:
     r"""
     Calculate the reverberation time in rooms as defined by Carl Eyring.
 
     The reverberation time is calculated according to Ref. [#]_ as
 
     .. math::
-        T_{60} = \frac{24 \cdot \ln(10)}{c}
+        T_{60} = -\frac{24 \cdot \ln(10)}{c}
         \cdot \frac{V}{S \ln(1 - \tilde{\alpha})}
 
     where :math:`V` is the room volume, :math:`S` is the total surface area
@@ -250,7 +250,7 @@ def reverberation_time_eyring(
 
     Returns
     -------
-    float, numpy.ndarray
+    numpy.ndarray
         Reverberation time in seconds. The shape matches the shape of the input
         variable `mean_absorption`.
 

From 31b4b00084d5359fa37596773af3e60acf9f9eb0 Mon Sep 17 00:00:00 2001
From: Marco Berzborn <m.berzborn@tue.nl>
Date: Thu, 19 Feb 2026 17:08:31 +0100
Subject: [PATCH 16/16] Update type hinting to be compatible with earlier numpy
 versions

---
 pyrato/parametric.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pyrato/parametric.py b/pyrato/parametric.py
index 72f98888..08d4ca91 100644
--- a/pyrato/parametric.py
+++ b/pyrato/parametric.py
@@ -218,9 +218,9 @@ def mean_free_path(
 def reverberation_time_eyring(
         volume: float,
         surface_area: float,
-        mean_absorption: Union[float, np.typing.NDArray[float]],
+        mean_absorption: Union[float, np.ndarray],
         speed_of_sound: float = 343.4,
-    ) -> np.typing.NDArray[float]:
+    ) -> np.ndarray:
     r"""
     Calculate the reverberation time in rooms as defined by Carl Eyring.