I'd say Chinese (or, at least, Mandarin) only because they have much stricter rules on what sounds can and cannot exist (For instance, a word cannot end with a "mm" sound, such as "thumb". As a result mandarin only has around 400 possible syllables whereas English has somewhere around 10,000-15,000). This is compensated by the use of tones (flat, rising, falling, swooping and neutral [short and punctuated]). Even so, one "word" can and often will literally have dozens of meanings. For example the word "horse" (馬) is pronounced "mǎ". Other words with the same sound and tone include: 碼, 瑪, 溤, 螞, 鷌, 嗎, 鎷 Limit that to sound only (no tone) and you have well over 100 possible words for "ma". Here's a Chinese tongue twister to demonstrate: 媽媽騎馬, (mā mā qí mǎ) 馬慢, (mǎ màn) 媽媽罵馬马嗎? (mā mā mà mǎ ma) [spoiler]Mother rides a horse. The horse is slow. Does mother scold the horse?[/spoiler] If you can't hear the tones, you can't narrow down the possibilities of words, which would make it exceedingly difficult when lip-reading.