The spelling of the word "Jaisen" can be explained using the International Phonetic Alphabet (IPA). The first sound is /dʒ/ which represents the "j" sound. The following sound is /eɪ/ which is a diphthong representing the "ai" sound in "rain". The third sound is /s/ for the letter "s". The fourth sound is /ən/ which is a schwa followed by "n" sound. Putting all of these sounds together, we arrive at the spelling of "Jaisen".