In many spoken cases you will be able to hear the difference between 得/地, because 得 is often realised as dé and 地 as dè.
Native speakers do make a conscious effort to use them in different situations in writing.
地 is used to link a verb and an adverb, as in
Or “the students ran back to the classroom quickly to prepare for lessons.”
You won't hear any difference in spoken because both are pronounced the same de.
In writing, 他高兴得跳起来 is correct. 他舒服地睡觉 and 他舒服得睡觉 are not idiomatic because they are not a typical Chinese way but English. We'd say 他睡得很舒服 in this case.