.. only:: html

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

        Click :ref:`here <sphx_glr_download_auto_examples_plot_signals_and_features.py>`     to download the full example code
    .. rst-class:: sphx-glr-example-title

    .. _sphx_glr_auto_examples_plot_signals_and_features.py:


=======================
Create and Plot Signals
=======================

Create and plot signals / noise; combine them at a specific SNR.

To see how soundpy implements this, see `soundpy.dsp.generate_sound`, 
`soundpy.dsp.generate_noise` and `soundpy.dsp.add_backgroundsound`.

Let's import soundpy


.. code-block:: default

    import soundpy as sp








Create a Signal
^^^^^^^^^^^^^^^

First let's set what sample rate we want to use


.. code-block:: default

    sr = 44100









Let's create a signal of 10 Hz 


.. code-block:: default

    sig1_hz = 10
    sig1, sr = sp.generate_sound(freq=sig1_hz, amplitude = 0.4, sr=sr, dur_sec=1)
    sp.plotsound(sig1, sr=sr, feature_type = 'signal',
                   title = 'Signal: {} Hz'.format(sig1_hz), subprocess=True)





.. image:: /auto_examples/images/sphx_glr_plot_signals_and_features_001.png
    :alt: Signal: 10 Hz
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/feats.py:117: UserWarning: Due to matplotlib using AGG backend, cannot display plot. Therefore, the plot will be saved here: current working directory
      warnings.warn(msg)




Let's create a signal of 20 Hz


.. code-block:: default

    sig2_hz = 20 
    sig2, sr = sp.generate_sound(freq=sig2_hz, amplitude= 0.4, sr=sr, dur_sec=1)
    sp.plotsound(sig2, sr=sr, feature_type = 'signal',
                   title = 'Signal: {} Hz'.format(sig2_hz), subprocess=True)




.. image:: /auto_examples/images/sphx_glr_plot_signals_and_features_002.png
    :alt: Signal: 20 Hz
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/feats.py:117: UserWarning: Due to matplotlib using AGG backend, cannot display plot. Therefore, the plot will be saved here: current working directory
      warnings.warn(msg)




Combine Signals 
^^^^^^^^^^^^^^^

Add them together and see what they look like:


.. code-block:: default

    sig3 = sig1 + sig2
    sp.plotsound(sig3, sr=sr, feature_type = 'signal', 
                   title='Mixed Signals: {} Hz + {} Hz'.format(sig1_hz, sig2_hz), 
                   subprocess=True)





.. image:: /auto_examples/images/sphx_glr_plot_signals_and_features_003.png
    :alt: Mixed Signals: 10 Hz + 20 Hz
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/feats.py:117: UserWarning: Due to matplotlib using AGG backend, cannot display plot. Therefore, the plot will be saved here: current working directory
      warnings.warn(msg)




Generate Pseudo-Random Noise
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Create noise to add to the signal:


.. code-block:: default

    noise = sp.generate_noise(len(sig3), amplitude=0.02, random_seed=40)
    sp.plotsound(noise, sr=sr, feature_type = 'signal',
                   title='Random Noise', subprocess=True)




.. image:: /auto_examples/images/sphx_glr_plot_signals_and_features_004.png
    :alt: Random Noise
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/feats.py:117: UserWarning: Due to matplotlib using AGG backend, cannot display plot. Therefore, the plot will be saved here: current working directory
      warnings.warn(msg)




Control SNR: Adding a Background Sound
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Add noise at signal-to-noise ratio of 40


.. code-block:: default

    sig_noisy, snr = sp.dsp.add_backgroundsound(
        audio_main = sig3, 
        audio_background = noise, 
        sr = sr,
        snr = 40,
        clip_at_zero = False)

    # keep energy between 1 and -1 
    sig_noisy = sp.dsp.scalesound(sig_noisy, max_val=1)
    sp.plotsound(sig_noisy, sr=sr, feature_type = 'signal', title='Signal + Noise: 40 SNR',
                 subprocess=True)




.. image:: /auto_examples/images/sphx_glr_plot_signals_and_features_005.png
    :alt: Signal + Noise: 40 SNR
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/dsp.py:769: UserWarning: 
    Warning: `soundpy.dsp.clip_at_zero` found no samples close to zero. Clipping was not applied.

      warnings.warn(msg)
    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/feats.py:117: UserWarning: Due to matplotlib using AGG backend, cannot display plot. Therefore, the plot will be saved here: current working directory
      warnings.warn(msg)




Add noise at signal-to-noise ratio of 20


.. code-block:: default

    sig_noisy, snr = sp.dsp.add_backgroundsound(
        audio_main = sig3, 
        audio_background = noise,
        sr = sr,
        snr = 20)
    # keep energy between 1 and -1 
    sig_noisy = sp.dsp.scalesound(sig_noisy, max_val=1)
    sp.plotsound(sig_noisy, sr=sr, feature_type = 'signal', title='Signal + Noise: 20 SNR',
                 subprocess=True)




.. image:: /auto_examples/images/sphx_glr_plot_signals_and_features_006.png
    :alt: Signal + Noise: 20 SNR
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/dsp.py:769: UserWarning: 
    Warning: `soundpy.dsp.clip_at_zero` found no samples close to zero. Clipping was not applied.

      warnings.warn(msg)
    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/feats.py:117: UserWarning: Due to matplotlib using AGG backend, cannot display plot. Therefore, the plot will be saved here: current working directory
      warnings.warn(msg)




Add noise at signal-to-noise ratio of 10


.. code-block:: default

    sig_noisy, snr = sp.dsp.add_backgroundsound(
        audio_main = sig3, 
        audio_background = noise,
        sr = sr,
        snr = 10)
    # keep energy between 1 and -1 
    sig_noisy = sp.dsp.scalesound(sig_noisy, max_val=1)
    sp.plotsound(sig_noisy, sr=sr, feature_type = 'signal', title='Signal + Noise: 10 SNR',
                 subprocess=True)




.. image:: /auto_examples/images/sphx_glr_plot_signals_and_features_007.png
    :alt: Signal + Noise: 10 SNR
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/dsp.py:769: UserWarning: 
    Warning: `soundpy.dsp.clip_at_zero` found no samples close to zero. Clipping was not applied.

      warnings.warn(msg)
    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/feats.py:117: UserWarning: Due to matplotlib using AGG backend, cannot display plot. Therefore, the plot will be saved here: current working directory
      warnings.warn(msg)




Add noise at signal-to-noise ratio of 0


.. code-block:: default

    sig_noisy, snr = sp.dsp.add_backgroundsound(
        audio_main = sig3,
        audio_background = noise,
        sr = sr,
        snr = 0)
    # keep energy between 1 and -1 
    sig_noisy = sp.dsp.scalesound(sig_noisy, max_val=1)
    sp.plotsound(sig_noisy, sr=sr, feature_type = 'signal', title='Signal + Noise: 0 SNR',
                 subprocess=True)





.. image:: /auto_examples/images/sphx_glr_plot_signals_and_features_008.png
    :alt: Signal + Noise: 0 SNR
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/feats.py:117: UserWarning: Due to matplotlib using AGG backend, cannot display plot. Therefore, the plot will be saved here: current working directory
      warnings.warn(msg)




Add noise at signal-to-noise ratio of -10


.. code-block:: default

    sig_noisy, snr = sp.dsp.add_backgroundsound(
        audio_main = sig3, 
        audio_background = noise,
        sr = sr,
        snr = -10)
    # keep energy between 1 and -1 
    sig_noisy = sp.dsp.scalesound(sig_noisy, max_val=1)
    sp.plotsound(sig_noisy, sr=sr, feature_type = 'signal', title='Signal + Noise: -10 SNR',
                 subprocess=True)



.. image:: /auto_examples/images/sphx_glr_plot_signals_and_features_009.png
    :alt: Signal + Noise: -10 SNR
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/airos/Projects/github/a-n-rose/Python-Sound-Tool/soundpy/feats.py:117: UserWarning: Due to matplotlib using AGG backend, cannot display plot. Therefore, the plot will be saved here: current working directory
      warnings.warn(msg)





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

   **Total running time of the script:** ( 0 minutes  3.053 seconds)


.. _sphx_glr_download_auto_examples_plot_signals_and_features.py:


.. only :: html

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



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

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



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

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


.. only:: html

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

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