How to detect the frequence of a sound in JavaScript?
<p>How can I detect if a sound is playing in the hearing range?</p>

<p>For example,</p>

<p>Show a silence icon if:</p>

<ul>
<li>The range is lower than <em>20 Hz</em>,</li>
<li>The range is higher than <em>20 kHz</em>.</li>
</ul>

<p>instead <code>stream.paused</code> is <code>false</code>.</p>