.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "gallery/modulations.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_gallery_modulations.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_gallery_modulations.py:


Generate FM, AM and SFM stimuli
===============================

This demonstrates how to generate amplitude, frequency, and spectrotemporal
modulated stimuli.

.. GENERATED FROM PYTHON SOURCE LINES 8-35

.. code-block:: Python

    import matplotlib.pyplot as plt
    import numpy as np

    from psiaudio import stim
    from psiaudio import util
    from psiaudio.calibration import FlatCalibration


    def plot_waveform(w, fs):
        figure, axes = plt.subplots(1, 3, figsize=(8, 8/3), constrained_layout=True)
        t = np.arange(len(w)) / fs
        axes[0].plot(t, w)
        axes[0].set_xlabel('Time (sec)')
        axes[0].set_ylabel(f'Amplitude (Pa)')
        axes[1].set_xlabel('Time (sec)')
        axes[1].set_ylabel('Frequency (kHz)')
        axes[1].specgram(w, Fs=fs);
        axes[1].set_yscale('octave', octaves=0.5)
        axes[1].axis(ymin=2e3, ymax=8e3, xmin=0, xmax=1)
        axes[2].plot(util.patodb((util.psd_df(w, fs=fs)).iloc[1:]))
        axes[2].set_xlabel('Frequency (kHz)')
        axes[2].set_ylabel('Amplitude (dB SPL)')
        axes[2].set_xscale('octave', octaves=0.5)
        axes[2].axis(ymin=0, xmin=2e3, xmax=8e3)
        return figure, axes









.. GENERATED FROM PYTHON SOURCE LINES 36-39

The AM and STM noise can both be generated using the `stm` function. The
difference is in the `cpo` (cycles per octave) being set to 0 for modulations
only in the time domain.

.. GENERATED FROM PYTHON SOURCE LINES 39-43

.. code-block:: Python


    fs = 16000









.. GENERATED FROM PYTHON SOURCE LINES 44-45

Add a taper to the rolloff.

.. GENERATED FROM PYTHON SOURCE LINES 45-82

.. code-block:: Python

    frequency = {
        'fc': 4e3,
        'octaves': 1,
        'rolloff_octaves': 0.25,
        'rolloff': 16,
    }

    w_stm = stim.stm(
        fs=fs,
        frequency=frequency,
        depth=9,
        duration=1,
        cpo=2,
        cps=4,
        mod_type='exp',
        calibration=FlatCalibration.from_spl(94),
        level=60,
    )

    w_am = stim.stm(
        fs=fs,
        frequency=frequency,
        depth=9,
        duration=1,
        cpo=0,
        cps=4,
        mod_type='exp',
        calibration=FlatCalibration.from_spl(94),
        level=60,
    )

    w_fm = stim.sfm(fs, 4e3, 4, 100, 1, 60, FlatCalibration.from_spl(94))

    plot_waveform(w_fm, fs)
    plot_waveform(w_am, fs)
    plot_waveform(w_stm, fs)
    plt.show()



.. rst-class:: sphx-glr-horizontal


    *

      .. image-sg:: /gallery/images/sphx_glr_modulations_001.png
         :alt: modulations
         :srcset: /gallery/images/sphx_glr_modulations_001.png
         :class: sphx-glr-multi-img

    *

      .. image-sg:: /gallery/images/sphx_glr_modulations_002.png
         :alt: modulations
         :srcset: /gallery/images/sphx_glr_modulations_002.png
         :class: sphx-glr-multi-img

    *

      .. image-sg:: /gallery/images/sphx_glr_modulations_003.png
         :alt: modulations
         :srcset: /gallery/images/sphx_glr_modulations_003.png
         :class: sphx-glr-multi-img






.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.791 seconds)


.. _sphx_glr_download_gallery_modulations.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: modulations.ipynb <modulations.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: modulations.py <modulations.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: modulations.zip <modulations.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_