From 78309783cbaa60eb5f979d0c771552f129cde92b Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Mon, 18 May 2026 17:23:16 -0400
Subject: [PATCH 01/11] Remove strategy from NoiseGeneratorRecording

---
 src/spikeinterface/generation/noise_tools.py | 51 ++++----------------
 1 file changed, 9 insertions(+), 42 deletions(-)

diff --git a/src/spikeinterface/generation/noise_tools.py b/src/spikeinterface/generation/noise_tools.py
index f64a8abe72..55bd03b694 100644
--- a/src/spikeinterface/generation/noise_tools.py
+++ b/src/spikeinterface/generation/noise_tools.py
@@ -1,5 +1,4 @@
 import numpy as np
-from typing import Literal
 
 from spikeinterface.core import BaseRecording, BaseRecordingSegment
 from spikeinterface.core.generate import _ensure_seed
@@ -33,12 +32,6 @@ class NoiseGeneratorRecording(BaseRecording):
         The dtype of the recording. Note that only np.float32 and np.float64 are supported.
     seed : int | None, default: None
         The seed for np.random.default_rng.
-    strategy : "tile_pregenerated" | "on_the_fly", default: "tile_pregenerated"
-        The strategy of generating noise chunk:
-          * "tile_pregenerated": pregenerate a noise chunk of noise_block_size sample and repeat it
-                                 very fast and cusume only one noise block.
-          * "on_the_fly": generate on the fly a new noise block by combining seed + noise block index
-                          no memory preallocation but a bit more computaion (random)
     noise_block_size : int, default: 30000
         Size in sample of noise block.
 
@@ -57,7 +50,6 @@ def __init__(
         cov_matrix: np.ndarray | None = None,
         dtype: np.dtype | str | None = "float32",
         seed: int | None = None,
-        strategy: Literal["tile_pregenerated", "on_the_fly"] = "tile_pregenerated",
         noise_block_size: int = 30000,
     ):
 
@@ -65,7 +57,6 @@ def __init__(
         dtype = np.dtype(dtype).name  # Cast to string for serialization
         if dtype not in ("float32", "float64"):
             raise ValueError(f"'dtype' must be 'float32' or 'float64' but is {dtype}")
-        assert strategy in ("tile_pregenerated", "on_the_fly"), "'strategy' must be 'tile_pregenerated' or 'on_the_fly'"
 
         if np.isscalar(noise_levels):
             noise_levels = np.ones((1, num_channels)) * noise_levels
@@ -103,7 +94,6 @@ def __init__(
                 cov_matrix,
                 dtype,
                 segments_seeds[i],
-                strategy,
             )
             self.add_recording_segment(rec_segment)
 
@@ -115,7 +105,6 @@ def __init__(
             "cov_matrix": cov_matrix,
             "dtype": dtype,
             "seed": seed,
-            "strategy": strategy,
             "noise_block_size": noise_block_size,
         }
 
@@ -131,7 +120,6 @@ def __init__(
         cov_matrix,
         dtype,
         seed,
-        strategy,
     ):
         assert seed is not None
 
@@ -144,23 +132,6 @@ def __init__(
         self.cov_matrix = cov_matrix
         self.dtype = dtype
         self.seed = seed
-        self.strategy = strategy
-
-        if self.strategy == "tile_pregenerated":
-            rng = np.random.default_rng(seed=self.seed)
-
-            if self.cov_matrix is None:
-                self.noise_block = (
-                    rng.standard_normal(size=(self.noise_block_size, self.num_channels), dtype=self.dtype)
-                    * noise_levels
-                )
-            else:
-                self.noise_block = rng.multivariate_normal(
-                    np.zeros(self.num_channels), self.cov_matrix, size=self.noise_block_size
-                )
-
-        elif self.strategy == "on_the_fly":
-            pass
 
     def get_num_samples(self) -> int:
         return self.num_samples
@@ -169,7 +140,7 @@ def get_traces(
         self,
         start_frame: int | None = None,
         end_frame: int | None = None,
-        channel_indices: list | None = None,
+        channel_indices: list | np.ndarray | tuple | None = None,
     ) -> np.ndarray:
 
         if start_frame is None:
@@ -188,18 +159,15 @@ def get_traces(
 
         pos = 0
         for block_index in range(first_block_index, last_block_index + 1):
-            if self.strategy == "tile_pregenerated":
-                noise_block = self.noise_block
-            elif self.strategy == "on_the_fly":
-                rng = np.random.default_rng(seed=(self.seed, block_index))
-                if self.cov_matrix is None:
-                    noise_block = rng.standard_normal(size=(self.noise_block_size, self.num_channels), dtype=self.dtype)
-                else:
-                    noise_block = rng.multivariate_normal(
-                        np.zeros(self.num_channels), self.cov_matrix, size=self.noise_block_size
-                    )
+            rng = np.random.default_rng(seed=(self.seed, block_index))
+            if self.cov_matrix is None:
+                noise_block = rng.standard_normal(size=(self.noise_block_size, self.num_channels), dtype=self.dtype)
+            else:
+                noise_block = rng.multivariate_normal(
+                    np.zeros(self.num_channels), self.cov_matrix, size=self.noise_block_size
+                )
 
-                noise_block *= self.noise_levels
+            noise_block *= self.noise_levels
 
             if block_index == first_block_index:
                 if first_block_index != last_block_index:
@@ -284,7 +252,6 @@ def generate_noise(
         sampling_frequency=sampling_frequency,
         durations=durations,
         dtype=dtype,
-        strategy="on_the_fly",
         noise_levels=noise_levels,
         cov_matrix=cov_matrix,
         seed=seed,

From 3282876865e825608493065f529338897843c823 Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Mon, 18 May 2026 17:42:26 -0400
Subject: [PATCH 02/11] Add spectral_density (impl. with a wrapper segment)

---
 src/spikeinterface/generation/noise_tools.py  | 65 ++++++++++++++++++-
 .../generation/tests/test_noise_tools.py      | 58 +++++++++++++++++
 2 files changed, 122 insertions(+), 1 deletion(-)

diff --git a/src/spikeinterface/generation/noise_tools.py b/src/spikeinterface/generation/noise_tools.py
index 55bd03b694..579fca994b 100644
--- a/src/spikeinterface/generation/noise_tools.py
+++ b/src/spikeinterface/generation/noise_tools.py
@@ -3,6 +3,8 @@
 from spikeinterface.core import BaseRecording, BaseRecordingSegment
 from spikeinterface.core.generate import _ensure_seed
 from spikeinterface.core.core_tools import define_function_from_class
+from spikeinterface.preprocessing.basepreprocessor import BasePreprocessorSegment
+from spikeinterface.core.recording_tools import get_chunk_with_margin
 
 
 class NoiseGeneratorRecording(BaseRecording):
@@ -28,6 +30,14 @@ class NoiseGeneratorRecording(BaseRecording):
         Std of the white noise (if an array, defined by per channels)
     cov_matrix : np.ndarray | None, default: None
         The covariance matrix of the noise
+    spectral_density : np.ndarray | None, default: None
+        The spectral density of the noise, as you could estimate from an array of snippets with shape
+        `(n_snippets, spectral_snippet_length)` by the following method (Welch's method):
+
+        ```python
+        periodogram = rfft(snippets, n=next_fast_len(snippets.shape[1]), norm="ortho")
+        spectral_density = np.sqrt((periodogram * periodogram.conj()).mean(axis=0))
+        ```
     dtype : np.dtype | str | None, default: "float32"
         The dtype of the recording. Note that only np.float32 and np.float64 are supported.
     seed : int | None, default: None
@@ -48,6 +58,7 @@ def __init__(
         durations: list[float],
         noise_levels: float | np.ndarray = 1.0,
         cov_matrix: np.ndarray | None = None,
+        spectral_density: np.ndarray | None = None,
         dtype: np.dtype | str | None = "float32",
         seed: int | None = None,
         noise_block_size: int = 30000,
@@ -95,6 +106,10 @@ def __init__(
                 dtype,
                 segments_seeds[i],
             )
+            if spectral_density is not None:
+                rec_segment = AddTemporalCorrelationsSegment(
+                    rec_segment, spectral_density
+                )
             self.add_recording_segment(rec_segment)
 
         self._kwargs = {
@@ -190,13 +205,52 @@ def get_traces(
         return traces
 
 
+class AddTemporalCorrelationsSegment(BasePreprocessorSegment):
+    def __init__(self, parent_recording_segment, spectral_density: np.ndarray):
+        super().__init__(parent_recording_segment)
+        assert spectral_density.ndim == 1
+        self.spectral_density = spectral_density
+        self.margin = spectral_density.shape[0] - 1
+        self.block_len = 2 * spectral_density.shape[0] - 1
+        self.kernel = np.fft.fftshift(np.fft.irfft(spectral_density, n=self.block_len))
+
+    def get_traces(
+        self,
+        start_frame: int | None = None,
+        end_frame: int | None = None,
+        channel_indices: list | np.ndarray | tuple | None = None,
+    ):
+        from scipy.signal import convolve
+
+        traces = get_chunk_with_margin(
+            self.parent_recording_segment,
+            start_frame=start_frame,
+            end_frame=end_frame,
+            channel_indices=channel_indices,
+            margin=self.margin,
+            add_reflect_padding=True,
+        )
+        # need to use "direct", or else output differs numerically when start_frame, end_frame change
+        # that's because the FFT method would FFT the traces, and there would be slight numerical differences
+        traces = convolve(traces.T, self.kernel[None], mode="valid", method="direct").T
+        return traces
+
+
+
 noise_generator_recording = define_function_from_class(
     source_class=NoiseGeneratorRecording, name="noise_generator_recording"
 )
 
 
 def generate_noise(
-    probe, sampling_frequency, durations, dtype="float32", noise_levels=15.0, spatial_decay=None, seed=None
+    probe,
+    sampling_frequency,
+    durations,
+    dtype="float32",
+    noise_levels=15.0,
+    spatial_decay=None,
+    spectral_density=None,
+    seed=None,
 ):
     """
     Generate a noise recording.
@@ -217,6 +271,14 @@ def generate_noise(
         If tuple, then this represent the range.
     spatial_decay : float | None, default: None
         If not None, the spatial decay of the noise used to generate the noise covariance matrix.
+    spectral_density : np.ndarray | None, default: None
+        The spectral density of the noise, as you could estimate from an array of snippets with shape
+        `(n_snippets, spectral_snippet_length)` by the following method (Welch's method):
+
+        ```python
+        periodogram = rfft(snippets, n=next_fast_len(snippets.shape[1]), norm="ortho")
+        spectral_density = np.sqrt((periodogram * periodogram.conj()).mean(axis=0))
+        ```
     seed : int | None, default: None
         The seed for random generator.
 
@@ -254,6 +316,7 @@ def generate_noise(
         dtype=dtype,
         noise_levels=noise_levels,
         cov_matrix=cov_matrix,
+        spectral_density=spectral_density,
         seed=seed,
     )
 
diff --git a/src/spikeinterface/generation/tests/test_noise_tools.py b/src/spikeinterface/generation/tests/test_noise_tools.py
index f633ed1de4..3463f91aae 100644
--- a/src/spikeinterface/generation/tests/test_noise_tools.py
+++ b/src/spikeinterface/generation/tests/test_noise_tools.py
@@ -1,7 +1,10 @@
+import numpy as np
 import probeinterface
+import pytest
 
 from spikeinterface.generation import (
     generate_noise,
+    NoiseGeneratorRecording,
 )
 
 
@@ -40,5 +43,60 @@ def test_generate_noise():
     # plt.show()
 
 
+@pytest.mark.parametrize("duration", [1.0, 2.0, 2.2])
+def test_noise_generator_temporal(duration):
+    psdlen = 25
+    kdomain = np.linspace(0.0, 10.0, psdlen)
+    fake_psd = (kdomain + 0.1) * np.exp(-kdomain)
+    # this ensures std dev of output ~= 1
+    fake_psd /= np.sqrt((fake_psd**2).mean())
+
+    # Test that the recording has the correct size in shape
+    sampling_frequency = 30000  # Hz
+    durations = [duration]
+    dtype = np.dtype("float32")
+    num_channels = 2
+    seed = 0
+
+    rec = NoiseGeneratorRecording(
+        num_channels=num_channels,
+        sampling_frequency=sampling_frequency,
+        durations=durations,
+        dtype=dtype,
+        seed=seed,
+        spectral_density=fake_psd,
+    )
+
+    # check output matches at different chunks
+    full_traces = rec.get_traces()
+    end_frame = rec.get_num_frames()
+    for t0 in [0, 100]:
+        for t1 in [end_frame, end_frame - 100]:
+            chk = rec.get_traces(0, t0, t1)
+            chk0 = full_traces[t0:t1]
+            np.testing.assert_array_equal(chk, chk0)
+
+    np.testing.assert_allclose(full_traces.std(), 1.0, rtol=0.02)
+
+    # re-estimate the psd from the result
+    # it will not be perfect, okay!
+    n = 2 * psdlen - 1
+    snips = full_traces[: n * (full_traces.shape[0] // n)]
+    snips = snips.reshape(-1, n, snips.shape[-1])
+    psd = np.fft.rfft(snips, n=n, axis=1, norm="ortho")
+    psd = np.sqrt(np.square(np.abs(psd)).mean(axis=(0, 2)))
+
+    sample_size = snips.shape[0] * snips.shape[2]
+    standard_error = 1.0 / np.sqrt(sample_size)
+
+    # accuracy is good at low freqs
+    np.testing.assert_allclose(
+        psd[1 : psdlen // 3],
+        fake_psd[1 : psdlen // 3],
+        atol=3 * standard_error,
+        rtol=0.1,
+    )
+    np.testing.assert_allclose(psd, fake_psd, atol=0.5)
+
 if __name__ == "__main__":
     test_generate_noise()

From 6ee700d12a6ec05ed8a518089e1658807ec7125e Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Mon, 18 May 2026 21:51:54 +0000
Subject: [PATCH 03/11] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 src/spikeinterface/generation/noise_tools.py            | 5 +----
 src/spikeinterface/generation/tests/test_noise_tools.py | 1 +
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/spikeinterface/generation/noise_tools.py b/src/spikeinterface/generation/noise_tools.py
index 579fca994b..89de50eab2 100644
--- a/src/spikeinterface/generation/noise_tools.py
+++ b/src/spikeinterface/generation/noise_tools.py
@@ -107,9 +107,7 @@ def __init__(
                 segments_seeds[i],
             )
             if spectral_density is not None:
-                rec_segment = AddTemporalCorrelationsSegment(
-                    rec_segment, spectral_density
-                )
+                rec_segment = AddTemporalCorrelationsSegment(rec_segment, spectral_density)
             self.add_recording_segment(rec_segment)
 
         self._kwargs = {
@@ -236,7 +234,6 @@ def get_traces(
         return traces
 
 
-
 noise_generator_recording = define_function_from_class(
     source_class=NoiseGeneratorRecording, name="noise_generator_recording"
 )
diff --git a/src/spikeinterface/generation/tests/test_noise_tools.py b/src/spikeinterface/generation/tests/test_noise_tools.py
index 3463f91aae..476b95631d 100644
--- a/src/spikeinterface/generation/tests/test_noise_tools.py
+++ b/src/spikeinterface/generation/tests/test_noise_tools.py
@@ -98,5 +98,6 @@ def test_noise_generator_temporal(duration):
     )
     np.testing.assert_allclose(psd, fake_psd, atol=0.5)
 
+
 if __name__ == "__main__":
     test_generate_noise()

From 6809fb0a9cad2d24a1eb6f73885df0b7500afedc Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Tue, 19 May 2026 10:01:16 -0400
Subject: [PATCH 04/11] tests: Removing some stray strategy args to the
 NoiseGeneratorRecording

---
 src/spikeinterface/core/generate.py                             | 2 +-
 src/spikeinterface/core/tests/test_generate.py                  | 2 --
 src/spikeinterface/curation/tests/common.py                     | 2 +-
 src/spikeinterface/exporters/tests/common.py                    | 2 +-
 src/spikeinterface/extractors/toy_example.py                    | 2 +-
 .../sortingcomponents/motion/tests/test_motion_interpolation.py | 2 +-
 src/spikeinterface/sortingcomponents/tests/common.py            | 2 +-
 src/spikeinterface/widgets/tests/test_widgets.py                | 2 +-
 8 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/src/spikeinterface/core/generate.py b/src/spikeinterface/core/generate.py
index 1470473fe2..d5afca9bc1 100644
--- a/src/spikeinterface/core/generate.py
+++ b/src/spikeinterface/core/generate.py
@@ -2286,7 +2286,7 @@ def generate_ground_truth_recording(
     upsample_factor=None,
     upsample_vector=None,
     generate_sorting_kwargs=dict(firing_rates=15, refractory_period_ms=4.0),
-    noise_kwargs=dict(noise_levels=5.0, strategy="on_the_fly"),
+    noise_kwargs=dict(noise_levels=5.0),
     generate_unit_locations_kwargs=dict(margin_um=10.0, minimum_z=5.0, maximum_z=50.0, minimum_distance=20),
     generate_templates_kwargs=None,
     dtype="float32",
diff --git a/src/spikeinterface/core/tests/test_generate.py b/src/spikeinterface/core/tests/test_generate.py
index c5a0b83f87..09849583dd 100644
--- a/src/spikeinterface/core/tests/test_generate.py
+++ b/src/spikeinterface/core/tests/test_generate.py
@@ -220,7 +220,6 @@ def test_noise_generator_several_noise_levels():
         dtype="float32",
         seed=32,
         noise_levels=1,
-        strategy="on_the_fly",
         noise_block_size=20000,
     )
     assert np.all(np.abs(get_noise_levels(rec1) - 1) < 0.1)
@@ -232,7 +231,6 @@ def test_noise_generator_several_noise_levels():
         dtype="float32",
         seed=32,
         noise_levels=[0, 1, 2, 3],
-        strategy="on_the_fly",
         noise_block_size=20000,
     )
     assert np.all(np.abs(get_noise_levels(rec2) - np.arange(4)) < 0.1)
diff --git a/src/spikeinterface/curation/tests/common.py b/src/spikeinterface/curation/tests/common.py
index a665b074a6..662dfdaa78 100644
--- a/src/spikeinterface/curation/tests/common.py
+++ b/src/spikeinterface/curation/tests/common.py
@@ -25,7 +25,7 @@ def make_sorting_analyzer(sparse=True, num_units=5, durations=[300.0]):
         num_channels=4,
         num_units=num_units,
         generate_sorting_kwargs=dict(firing_rates=20.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=5.0, strategy="on_the_fly"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
 
diff --git a/src/spikeinterface/exporters/tests/common.py b/src/spikeinterface/exporters/tests/common.py
index d86df0c6c8..186f850b88 100644
--- a/src/spikeinterface/exporters/tests/common.py
+++ b/src/spikeinterface/exporters/tests/common.py
@@ -18,7 +18,7 @@ def make_sorting_analyzer(sparse=True, with_group=False):
             contact_shape_params={"radius": 6},
         ),
         generate_sorting_kwargs=dict(firing_rates=10.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=5.0, strategy="on_the_fly"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
 
diff --git a/src/spikeinterface/extractors/toy_example.py b/src/spikeinterface/extractors/toy_example.py
index 626ea0050a..fb028a5707 100644
--- a/src/spikeinterface/extractors/toy_example.py
+++ b/src/spikeinterface/extractors/toy_example.py
@@ -155,7 +155,7 @@ def toy_example(
         ms_after=ms_after,
         dtype="float32",
         seed=seed,
-        noise_kwargs=dict(noise_levels=10.0, strategy="on_the_fly"),
+        noise_kwargs=dict(noise_levels=10.0),
     )
 
     return recording, sorting
diff --git a/src/spikeinterface/sortingcomponents/motion/tests/test_motion_interpolation.py b/src/spikeinterface/sortingcomponents/motion/tests/test_motion_interpolation.py
index 9635bad48b..7c232a4328 100644
--- a/src/spikeinterface/sortingcomponents/motion/tests/test_motion_interpolation.py
+++ b/src/spikeinterface/sortingcomponents/motion/tests/test_motion_interpolation.py
@@ -241,7 +241,7 @@ def test_InterpolateMotionRecording():
             contact_shape_params={"radius": 6},
         ),
         generate_sorting_kwargs=dict(firing_rates=6.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=5.0, strategy="on_the_fly"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
 
diff --git a/src/spikeinterface/sortingcomponents/tests/common.py b/src/spikeinterface/sortingcomponents/tests/common.py
index e8bee33794..c691c70f15 100644
--- a/src/spikeinterface/sortingcomponents/tests/common.py
+++ b/src/spikeinterface/sortingcomponents/tests/common.py
@@ -16,7 +16,7 @@ def make_dataset():
             contact_shape_params={"radius": 6},
         ),
         generate_sorting_kwargs=dict(firing_rates=6.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=5.0, strategy="on_the_fly"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
 
diff --git a/src/spikeinterface/widgets/tests/test_widgets.py b/src/spikeinterface/widgets/tests/test_widgets.py
index c811c386e2..5468b373e9 100644
--- a/src/spikeinterface/widgets/tests/test_widgets.py
+++ b/src/spikeinterface/widgets/tests/test_widgets.py
@@ -54,7 +54,7 @@ def setUpClass(cls):
                 contact_shape_params={"radius": 6},
             ),
             generate_sorting_kwargs=dict(firing_rates=10.0, refractory_period_ms=4.0),
-            noise_kwargs=dict(noise_levels=5.0, strategy="on_the_fly"),
+            noise_kwargs=dict(noise_levels=5.0),
             seed=2205,
         )
         # cls.recording = recording.save(folder=cache_folder / "recording")

From 16257621430c8188cabcb132fae01b8d80c39bc7 Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Tue, 19 May 2026 10:08:06 -0400
Subject: [PATCH 05/11] tests: del 'tile_pregenerated' kw to
 `generate_ground_truth_recording()`

---
 src/spikeinterface/core/tests/test_analyzer_extension_core.py   | 2 +-
 src/spikeinterface/core/tests/test_sorting_tools.py             | 2 +-
 src/spikeinterface/core/tests/test_sortinganalyzer.py           | 2 +-
 src/spikeinterface/core/tests/test_sparsity.py                  | 2 +-
 src/spikeinterface/core/tests/test_template_tools.py            | 2 +-
 src/spikeinterface/core/tests/test_waveform_tools.py            | 2 +-
 .../tests/test_waveforms_extractor_backwards_compatibility.py   | 2 +-
 7 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/spikeinterface/core/tests/test_analyzer_extension_core.py b/src/spikeinterface/core/tests/test_analyzer_extension_core.py
index fd550c729e..f0b918af6c 100644
--- a/src/spikeinterface/core/tests/test_analyzer_extension_core.py
+++ b/src/spikeinterface/core/tests/test_analyzer_extension_core.py
@@ -30,7 +30,7 @@ def get_sorting_analyzer(cache_folder, format="memory", sparse=True):
                 alpha=(200.0, 500.0),
             )
         ),
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2406,
     )
     if format == "memory":
diff --git a/src/spikeinterface/core/tests/test_sorting_tools.py b/src/spikeinterface/core/tests/test_sorting_tools.py
index 4194f459b3..92b68373bf 100644
--- a/src/spikeinterface/core/tests/test_sorting_tools.py
+++ b/src/spikeinterface/core/tests/test_sorting_tools.py
@@ -52,7 +52,7 @@ def test_random_spikes_selection():
         num_channels=10,
         num_units=5,
         generate_sorting_kwargs=dict(firing_rates=10.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
     max_spikes_per_unit = 12
diff --git a/src/spikeinterface/core/tests/test_sortinganalyzer.py b/src/spikeinterface/core/tests/test_sortinganalyzer.py
index a9bd71b5c0..648c926860 100644
--- a/src/spikeinterface/core/tests/test_sortinganalyzer.py
+++ b/src/spikeinterface/core/tests/test_sortinganalyzer.py
@@ -31,7 +31,7 @@ def get_dataset():
         num_channels=10,
         num_units=5,
         generate_sorting_kwargs=dict(firing_rates=10.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
 
diff --git a/src/spikeinterface/core/tests/test_sparsity.py b/src/spikeinterface/core/tests/test_sparsity.py
index 6e85221621..59f46c5699 100644
--- a/src/spikeinterface/core/tests/test_sparsity.py
+++ b/src/spikeinterface/core/tests/test_sparsity.py
@@ -152,7 +152,7 @@ def get_dataset():
         num_channels=10,
         num_units=5,
         generate_sorting_kwargs=dict(firing_rates=10.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=1.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=1.0),
         seed=2205,
     )
     recording.set_property("group", ["a"] * 5 + ["b"] * 5)
diff --git a/src/spikeinterface/core/tests/test_template_tools.py b/src/spikeinterface/core/tests/test_template_tools.py
index a28680612a..c6e78c2a37 100644
--- a/src/spikeinterface/core/tests/test_template_tools.py
+++ b/src/spikeinterface/core/tests/test_template_tools.py
@@ -19,7 +19,7 @@ def get_sorting_analyzer():
         sampling_frequency=10_000.0,
         num_channels=4,
         num_units=10,
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
     recording.annotate(is_filtered=True)
diff --git a/src/spikeinterface/core/tests/test_waveform_tools.py b/src/spikeinterface/core/tests/test_waveform_tools.py
index 5e0350f833..0d677129ac 100644
--- a/src/spikeinterface/core/tests/test_waveform_tools.py
+++ b/src/spikeinterface/core/tests/test_waveform_tools.py
@@ -29,7 +29,7 @@ def get_dataset():
         num_channels=4,
         num_units=7,
         generate_sorting_kwargs=dict(firing_rates=5.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=1.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=1.0),
         seed=2205,
     )
     return recording, sorting
diff --git a/src/spikeinterface/core/tests/test_waveforms_extractor_backwards_compatibility.py b/src/spikeinterface/core/tests/test_waveforms_extractor_backwards_compatibility.py
index e75f3be156..702cfc7ad1 100644
--- a/src/spikeinterface/core/tests/test_waveforms_extractor_backwards_compatibility.py
+++ b/src/spikeinterface/core/tests/test_waveforms_extractor_backwards_compatibility.py
@@ -34,7 +34,7 @@ def get_dataset():
                 alpha=(100.0, 500.0),
             )
         ),
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2406,
     )
     return recording, sorting

From 330f50cb5e7b27279373045e74321d3b1ebda894 Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Tue, 19 May 2026 10:24:04 -0400
Subject: [PATCH 06/11] tests: remove tile_pregenerated in analyzer extension
 tests

---
 .../postprocessing/tests/common_extension_tests.py              | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/spikeinterface/postprocessing/tests/common_extension_tests.py b/src/spikeinterface/postprocessing/tests/common_extension_tests.py
index e03d54fe74..f565fe6a21 100644
--- a/src/spikeinterface/postprocessing/tests/common_extension_tests.py
+++ b/src/spikeinterface/postprocessing/tests/common_extension_tests.py
@@ -30,7 +30,7 @@ def get_dataset():
                 alpha=(100.0, 500.0),
             )
         ),
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
     return recording, sorting

From c8afd1e05a6ea7b2464507cf36df36d8da3a7469 Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Tue, 19 May 2026 10:33:58 -0400
Subject: [PATCH 07/11] tests: del tile_pregenerated in test_multi_extensions

---
 .../postprocessing/tests/test_multi_extensions.py             | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/spikeinterface/postprocessing/tests/test_multi_extensions.py b/src/spikeinterface/postprocessing/tests/test_multi_extensions.py
index e3c45fe8ef..820aaad4f6 100644
--- a/src/spikeinterface/postprocessing/tests/test_multi_extensions.py
+++ b/src/spikeinterface/postprocessing/tests/test_multi_extensions.py
@@ -70,7 +70,7 @@ def get_dataset_to_merge():
         num_channels=10,
         num_units=10,
         generate_sorting_kwargs=dict(firing_rates=10.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         generate_unit_locations_kwargs=dict(margin_um=10.0, minimum_z=2.0, maximum_z=15.0, minimum_distance=20),
         seed=2205,
     )
@@ -102,7 +102,7 @@ def get_dataset_to_split():
         num_channels=10,
         num_units=10,
         generate_sorting_kwargs=dict(firing_rates=10.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
 

From 53a5a641e2d7e49bade94be402527dfd5bb84a12 Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Tue, 19 May 2026 10:46:07 -0400
Subject: [PATCH 08/11] tests: del tile_pregenerated in test_metrics_functions

---
 .../metrics/quality/tests/test_metrics_functions.py             | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/spikeinterface/metrics/quality/tests/test_metrics_functions.py b/src/spikeinterface/metrics/quality/tests/test_metrics_functions.py
index e267b176ce..04b3c068fb 100644
--- a/src/spikeinterface/metrics/quality/tests/test_metrics_functions.py
+++ b/src/spikeinterface/metrics/quality/tests/test_metrics_functions.py
@@ -84,7 +84,7 @@ def _sorting_analyzer_violations():
         sampling_frequency=sorting.sampling_frequency,
         num_channels=6,
         sorting=sorting,
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
     sorting_analyzer = create_sorting_analyzer(sorting, recording, format="memory", sparse=True)

From 608577feec2bbd7c552f9878ec880cab39bdfdb9 Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Tue, 19 May 2026 10:59:40 -0400
Subject: [PATCH 09/11] tests: del tile_pregenerated in metrics/conftest

---
 src/spikeinterface/metrics/conftest.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/spikeinterface/metrics/conftest.py b/src/spikeinterface/metrics/conftest.py
index 5313e763c1..e43a044d2d 100644
--- a/src/spikeinterface/metrics/conftest.py
+++ b/src/spikeinterface/metrics/conftest.py
@@ -65,7 +65,7 @@ def sorting_analyzer_simple():
                 alpha=(200.0, 500.0),
             )
         ),
-        noise_kwargs=dict(noise_levels=5.0, strategy="tile_pregenerated"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=1205,
     )
 

From 8c1bb86fceed2ed3aaf35ef3d4428e10971eb157 Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Tue, 19 May 2026 11:00:46 -0400
Subject: [PATCH 10/11] tests: del on_the_fly in common_benchmark_testing

---
 src/spikeinterface/benchmark/tests/common_benchmark_testing.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/spikeinterface/benchmark/tests/common_benchmark_testing.py b/src/spikeinterface/benchmark/tests/common_benchmark_testing.py
index 49f9e9350a..6833babc5f 100644
--- a/src/spikeinterface/benchmark/tests/common_benchmark_testing.py
+++ b/src/spikeinterface/benchmark/tests/common_benchmark_testing.py
@@ -39,7 +39,7 @@ def make_dataset(job_kwargs={}):
             contact_shape_params={"radius": 6},
         ),
         generate_sorting_kwargs=dict(firing_rates=6.0, refractory_period_ms=4.0),
-        noise_kwargs=dict(noise_levels=5.0, strategy="on_the_fly"),
+        noise_kwargs=dict(noise_levels=5.0),
         seed=2205,
     )
 

From c4a035d411403ba931c55796c1a348e2de0ee758 Mon Sep 17 00:00:00 2001
From: Charlie Windolf <charliexwindolf@gmail.com>
Date: Tue, 19 May 2026 11:27:03 -0400
Subject: [PATCH 11/11] noise: forgot that get_chunk_with_margin() -> tuple.
 also assert length is correct.

---
 src/spikeinterface/generation/noise_tools.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/spikeinterface/generation/noise_tools.py b/src/spikeinterface/generation/noise_tools.py
index 89de50eab2..e3b6a28c47 100644
--- a/src/spikeinterface/generation/noise_tools.py
+++ b/src/spikeinterface/generation/noise_tools.py
@@ -220,7 +220,12 @@ def get_traces(
     ):
         from scipy.signal import convolve
 
-        traces = get_chunk_with_margin(
+        if start_frame is None:
+            start_frame = 0
+        if end_frame is None:
+            end_frame = self.get_num_samples()
+
+        traces, *_ = get_chunk_with_margin(
             self.parent_recording_segment,
             start_frame=start_frame,
             end_frame=end_frame,
@@ -231,6 +236,7 @@ def get_traces(
         # need to use "direct", or else output differs numerically when start_frame, end_frame change
         # that's because the FFT method would FFT the traces, and there would be slight numerical differences
         traces = convolve(traces.T, self.kernel[None], mode="valid", method="direct").T
+        assert traces.shape[0] == end_frame - start_frame
         return traces