Many people feel like Spanish or Japanese speakers are rushing, whereas Chinese or German speakers are much slower.
A study by French researcher François Pellegrino with 59 speakers of 7 languages has confirmed this feeling, so it’s true that “some spoken languages are faster than others”.
However, they also found out that there is less information in a Spanish syllable than in a Chinese one, so the “information density” is not the same in every language. Taking this parameter in consideration, and when calculating “information speed” rather than “syllable speed”, they found that all languages have approximately the same speed.
So to answer the question “are some spoken languages faster than others?”, it depends on what speed weare refering to…
More detail in this Scientific American article.