For the ears, you can listen to an audio recording of this presentation.
[high fidelity audio playable under all personal computer operating systems via VLC media player, Microsoft Windows Media Player with the Xiph.org codecs for FLAC et al, OS X QuickTime with the XiphQT plugin, etc., on many Android-based mobile devices, and on iOS-based mobile devices via apps such as FLAC Player or Golden Ear]