The spelling of the word "CBCTA" can be explained using the International Phonetic Alphabet (IPA). "CBCTA" is spelled /siːbiːsiːtiːei/ in IPA. Each letter represents a phoneme (distinct speech sound) in this sequence. The first three letters (C, B, and C) represent the sounds /siː/, /biː/, and /siː/ respectively. The last two letters (T and A) represent the sounds /tiː/ and /ei/ respectively. When pronounced together, these sounds make up the word "CBCTA".