Prosodic mapping of text font based on the dimensional theory of emotions: a case study on style and size

Current text-to-speech systems do not support the effective provision of the semantics and the cognitive aspects of the documents’ typographic cues (e.g., font type, style, and size). A novel approach is introduced for the acoustic rendition of text font based on the emotional analogy between the visual (text font cues) and the acoustic (speech prosody) modalities. The methodology is based on: a) modeling reader’s emotional state response (“Pleasure”, “Arousal” and “Dominance”) induced by the document’s font cues and b) the acoustic mapping of the emotional state using expressive speech synthesis. A case study was conducted for the proposed methodology by calculating the prosodic values on specific font cues (several font styles and font sizes) and by examining listeners’ preferences on the acoustic rendition of bold, italics, bold-italics, and various font sizes. The experimental results after the user evaluation indicate that the acoustic rendition of font size variations as well as bold and italics is recognized successfully, but bold-italics are confused with bold, due to the similarities of their prosodic variations.