Purely subjectively, as someone with a hearing loss who has learned a couple other languages (plus teaching myself how to speak my native English understandably

Purely subjectively, as someone with a hearing loss who has learned a couple other languages (plus teaching myself how to speak my native English understandably) I do think that different languages may be easier or harder for people to lipread, at least in my situation. Mandarin encodes a great deal of the information into the vowel including the tone. This is only partly visible, at best. (But I can hear this part just fine.) The various initial consonants are all visible on the lips. With the exception of the the aspiration contrast (Pinyin t/d, g/k etc.) which is almost invisible, and probably poses the biggest challenge. Voicing contrast like in English or French is also very hard to see. (But in my case easier to hear.) On the other hand, I find both for lipreading and hearing in English or French, it is the final consonants in syllables and the contrast between various consonant clusters I tend to lose. I'm not sure which is innately harder, they definitely pose different challenges. As an aside, it's an amazingly complex process cognitively, correlating often extremely subtle facial movements with particular sounds. And most of us do it! We're watching people's eyes and lips and chin and even their voice box and nostrils as they speak. And not just the hard of hearing. It's a classic and reproducible effect, where adding video of the speaker's face can make quiet or noisy borderline unintelligible speech suddenly quite intelligible. And when researchers play tricks, such as with visual information that conflicts with the auditory, the visual channel will often influence or even take priority over what is actually heard: https://en.wikipedia.org/wiki/McGurk_effect https://en.wikipedia.org/wiki/McGurk_effect