undoing changes to signal_representations.ipynb

notebooks/signal_representations.ipynb

 {
  "metadata": {
   "name": "",
-  "signature": "sha256:0f5bdcdb555e9e415e3ddb05f3eee4995c96e8ad80dd3738a9fd6235988030e1"
+  "signature": "sha256:ae6c27deba8367f15947de6fb73b13258b984d8121de375ff949577a6d459d95"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -74,13 +74,13 @@
        ],
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 1,
+       "prompt_number": 12,
        "text": [
-        "<IPython.lib.display.Audio at 0x387ec90>"
+        "<IPython.lib.display.Audio at 0xefadad0>"
        ]
       }
      ],
-     "prompt_number": 1
+     "prompt_number": 12
     },
     {
      "cell_type": "markdown",