Publication: IEICE TRANSACTIONS on Information and Systems Publication Date: 2014/06/01 Vol. E97-DNo. 6pp. 1419-1428 Type of Manuscript: Special Section PAPER (Special Section on Advances in Modeling for Real-world Speech Information Processing and its Application) Category: Voice Conversion and Speech Enhancement Keyword: singing voice, voice conversion, perceived age, spectral and prosodic features, subjective evaluations,