replace in opening quotations

node181.html

@@ -11,8 +11,8 @@ original version by:  Nikos Drakos, CBLU, University of Leeds
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
 
-<TITLE>Timbre stamp (``vocoder")</TITLE>
-<META NAME="description" CONTENT="Timbre stamp (``vocoder")">
+<TITLE>Timbre stamp ("vocoder")</TITLE>
+<META NAME="description" CONTENT="Timbre stamp ("vocoder")">
 <META NAME="keywords" CONTENT="book">
 <META NAME="resource-type" CONTENT="document">
 <META NAME="distribution" CONTENT="global">
@@ -66,7 +66,7 @@ original version by:  Nikos Drakos, CBLU, University of Leeds
 <!--End of Navigation Panel-->
 
 <H2><A NAME="SECTION001373000000000000000">
-Timbre stamp (``vocoder")</A>
+Timbre stamp ("vocoder")</A>
 </H2>
 
 <P>
@@ -99,7 +99,7 @@ are <IMG
  WIDTH="28" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
  SRC="img1237.png"
  ALT="$c[k]$"> for the control source, we just
-``whiten" the filter input, multiplying by <IMG
+"whiten" the filter input, multiplying by <IMG
  WIDTH="46" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
  SRC="img1238.png"
  ALT="$1/f[k]$">, and then stamp the control
@@ -113,7 +113,7 @@ done by limiting the whitening factor <IMG
  SRC="img1238.png"
  ALT="$1/f[k]$"> to a specified maximum value
 using the <TT>clip~</TT> object.  The limit is controlled by the
-``squelch" parameter, which is squared and divided by 100 to map values
+"squelch" parameter, which is squared and divided by 100 to map values
 from 0 to 100 to a useful range.
 
 <P>