tidybayes has support for extracting draws from emmeans objects and then summarizing them using whatever interval type you want. Something like this might work:
library(emmeans)
library(tidybayes)
model4b.model %>%
emmeans( ~ noise_level * token) %>%
contrast(method = "pairwise") %>%
gather_emmeans_draws() %>%
median_qi(.width = .90)
That will give you median and 90% quantile (equal-tailed) intervals. If you want highest-density intervals, you could use something like mode_hdi in place of median_qi. The full set of variants is [mean|median|mode]_[qi|hdi|hdci], where hdi is highest-density (not necessarily continuous) interval, and hdci is highest-density continuous interval — i.e. hdi may return multiple intervals, which might be undesirable; hdci does not, though the result is not necessarily an HDI.
For more examples of tidybayes + emmeans (including plots), see here