Sjoerd Mullender:

The (relatively) new chunk module uses seek, not setpos.  One instance
of the call still needed to be fixed.
diff --git a/Lib/aifc.py b/Lib/aifc.py
index f7288d5..0af6622 100644
--- a/Lib/aifc.py
+++ b/Lib/aifc.py
@@ -404,7 +404,7 @@
             dummy = self._ssnd_chunk.read(8)
             pos = self._soundpos * self._framesize
             if pos:
-                self._ssnd_chunk.setpos(pos + 8)
+                self._ssnd_chunk.seek(pos + 8)
             self._ssnd_seek_needed = 0
         if nframes == 0:
             return ''