As your Wikipedia link discusses, the &quot;internal voice&quot; is a <i>component</i> of subvocalization, but subvocalization also includes other things that happen at the same time (involuntary muscle movements.)<p>&gt; If I had to try to think about them as different concepts, I&#x27;d probably say that I never subvocalize, and usually don&#x27;t hear a voice when reading quickly, but perhaps do hear a voice when reading slowly or focusing on individual words.<p>Since the involuntary muscle movements that are the other part of subvocalization are generally <i>undetectable to the person doing the reading</i>, what is your basis for saying that you <i>never</i> subvocalize, even though you do hear a voice when reading slowly?