Laryngeals do not work

[RaphiSpoerri]

Trying to produce laryngeal sounds doesn't work, neither with the UI:

IMG_5443.mov

Nor do they work properly with the API. For example, based on the demo index.html:

say({}, { index: 4.5, diameter: 0 }, 0.1, 0.5, 0, 0);

I would expect this to be a glottal stop [ʔ], because the diameter is 0, but instead, it always makes a hissing noise, similar to [h]. Moreover, the laryngeal tongue animations never work, even with the API.