Languages like Spanish and Japanese do get more “syllables per second” out than English, but syllable speed isn’t the whole story.
Languages that are spoken faster tend to pack less information into each syllable, making up the difference. Languages like Mandarin pack more information into each syllable, although they are spoken slower.
When the two factors are combined, humans convey information at approximately the same rate, indepently of language: about 39 bits per second.
This trade-off is similar to computer networks, where, according to Nyquist and Shannon, if you have less symbols, you can send them faster with the same bandwidth.
Although languages convey information at the same rate, I do wonder what would happen if we measured different SNR (Signal-Noise Ratio) conditions.
Theoretically, Spanish and Japanese should be more robust in low SNR (noisy) environments than high-density languages like Mandarin or English.
This is a short piece of scientific outreach based on the article: Coupé, C., Oh, Y. M., Dediu, D., & Pellegrino, F. (2019). Different languages, similar encoding efficiency: Comparable information rates across the human communicative niche. Science Advances, 5(9). https://doi.org/10.1126/sciadv.aaw2594