The "Audio Messaging System" is described here: https://www.we-teve.com/watch/lPHnZn7P

Better microphone from 32:16 onwards.

0:00 Origin and background of the "Audio Messaging System"
3:23 Origin of the reply-tree, and that a visual indicator for recording in progress is needed
5:34 Handling of device access permissions in the browser
9:28 Update: Can't request permanent device access permission in the browser, recording indicator
14:15 Progressive Web App (PWA) for mobile
17:14 Notifications
18:45 Asynchronous audio messaging as generalized capability
22:04 Audio for/with Augmented Reality
24:54 Potential of asynchronous discussions and conversation
32:16 Hypermedia and annotations in/with/on audio
35:03 User management, grouping messages into "rooms"
38:41 Origin of the tree navigation: tooling attempt for media/content curation
42:06 Tree vs. graph for navigation and curation
47:46 Flat room list instead of an ever-branching tree to hold messages
51:20 Deletion of recordings
53:41 Playback issues with mobile browser: custom audio player needed for playback on mobile
59:52 Audio (speaking/listening: passive) more convenient than text (writing/reading: active)
1:05:08 Phone box, answering machines, voicemail
1:06:34 Re-use of recordings (clips, snippets)
1:09:12 Provisional replacement of the tree with a flat list of rooms
1:12:16 Audio annotations on computer program source code?