Halo: The Master Chief Collection

29 audio recordings are located in the "Streets of Mombasa" location. Another one is at the “Infoley” level, which will become available if you collect all previous audio recordings. Audio recordings collected while playing in co-op do not count toward unlocking the last audio recording. It is better to start the search from the last checkpoint of the "HeadquartersPUNM" level, after completion of which you will have access to all areas of the "Streets of Mombasa" location.

https://www.youtube.com/watch?v=_LKgUmmYK9E

https://www.youtube.com/watch?v=W7BCEBGHiQs