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diff --git a/modules/sound/macros/mu2lin.sci b/modules/sound/macros/mu2lin.sci
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+function [y]=mu2lin(mu)
+    //Utility fct: converts mu-law encoding to linear signal.
+    //   y=mu2lin(mu) converts mu-law encoded 8-bit audio signals,
+    //   stored in the range 0 <= mu <= 255, to
+    //   linear signal amplitude in the range -s < y < s where
+    //   s = 32124/32768 ~= .9803.  The input mu is often obtained
+    //   using mget(...,'uc') to read byte-encoded audio files.
+    //  Translation of C program by:
+    //  Craig Reese: IDA/Supercomputing Research Center
+    //  Joe Campbell: Department of Defense
+    //  29 September 1989
+    SCALE = 1/32768;
+    ETAB = [0,132,396,924,1980,4092,8316,16764];
+    mu = 255-mu;
+    sig = mu>127;
+    e = fix(mu/16)-8*bool2s(sig)+1;
+    f = mu-fix(mu./16).*16;
+    y = f.*2.^(e+2);
+    e(:) = ETAB(e);
+    y = SCALE*(1-2*bool2s(sig)) .* (e+y);
+endfunction