Final answer:
The 'ei' in 'kaleidoscope' is pronounced as a long [i] sound.
Step-by-step explanation:
The vowel sound that ei makes in the word kaleidoscope is pronounced as a long [i] sound. This pronunciation can vary across different words in English, but in the case of kaleidoscope, the ei follows the pattern where ei is pronounced as [i] similar to the sound in receive or deceive. The pronunciation of vowels can be tricky in English due to the many exceptions and variations from the standard phonetic rules.