Roughly is the operative word there. It's a ballpark figure, like within an order or magnitude. It's hard to quantify in the first place. We can think of a l

Roughly is the operative word there. It's a ballpark figure, like within an order or magnitude. It's hard to quantify in the first place. We can think of a language like a digital modulation, with the set of sounds being a symbol constellation, and the syllable time, as the baud rate. When you do such numbers, most (all?) languages fall in a fairly narrow window (something like 30 - 50 bits of actual information per second at average speaking speed). If a language has fewer possible sounds, the syllables come more quickly. This is an innate tradeoff with a communication channel in information theory. But the analogy is only partial because, unlike most designed protocols, the symbol distribution is not a normal or random distribution. And human language has, in information theory terms, internal redundancy and compression (pronouns do a table lookup) as well as error correction codes and checksums (most combinations are illegal). This makes a analogy beteeen spoken language and a modem less than straightforward, though they are governed by the same underlying laws.