<span class="o">.</span><span class="n">ndarray</span><span class="p">:</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Computes the envelope of a given signal spectrum.</span>

<span class="sd">    Parameters</span>
<span class="sd">    ----------</span>
<span class="sd">    X : np.ndarray [shape=(K,M+1)] , complex-valued</span>
<span class="sd">        A complex spectrogram</span>

<span class="sd">    filt_len : int</span>
<span class="sd">        Length of the convolution wind