Complex sentence: Sending letters at higher speeds discourages the learner from hearing distinct dots and dashes, and analysing them too closely, instead, the dots and dashes that make up each letter, are percieved as a single unit.
Split into simpler sentences: Sending letters at higher speeds discourages the learner from hearing distinct dots and dashes, and analysing them too closely. Instead, the dots and dashes that make up each letter are percieved as a single unit.