diff --git a/README.md b/README.md
index 0c8617b2..6ee5da1d 100644
--- a/README.md
+++ b/README.md
@@ -82,7 +82,6 @@ Developed in the [Computer Graphcis and Virtual Reality Study Lab](https://cgvr.
 | Fire-suppressing gas release sound                  | Creative Commons 0                           | [Link](https://freesound.org/people/mrmccormack/sounds/182359/)                            | mrmccormack      |
 | Coughing sound in response to fire-suppressing gas  | Attribution 4.0                              | [Link](https://freesound.org/people/qubodup/sounds/739416/)                                | qubodup          |
 | Robot movement sound                                | Creative Commons 0                           | [Link](https://freesound.org/people/Brazilio123/sounds/661435/)                            | Brazilio123      |
-| Portal humming sound                                | Attribution 4.0                              | [Link](https://freesound.org/people/zimbot/sounds/122972/)                                 | zimbot           |
 | Spacewalk UFO sound                                 | Attribution NonCommercial 4.0                           | [Link](https://freesound.org/people/Speedenza/sounds/209366/)                           | Speedenza     |
 | Keyboard icons                                      | Creative Commons Attribution-NoDerivs 3.0    | [Link](https://icons8.com/)                                                                 | icons8           |