ow</span>

<span class="sd">    Returns</span>
<span class="sd">    -------</span>
<span class="sd">    env : np.ndarray [shape=(K,M+1)] , real-valued</span>
<span class="sd">        Spectral Envelope</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="n">kern</span> <span class="o">=</span> <span class="n">win</span><span class="p">(</span><span class="n">filt_len</span><span class="p">,</span> <span class="mi">2</span><span class="p">)</span>  <span class="c1"># Hann Window</span>
    <