About 40 million mild to severe deaf people have telephone conversations world wide. Often they have difficulty understanding the telephone speech. The intelligibility of telephone speech is much lower than that of person–to– person speech, the major factors being: - Loss of quality and information - Additional noise - Lack of visual cues This book analyzes the factors and explore various telephone speech enhancement techniques for better comprehensibility of the hearing impaired. In this attempt, the book discusses the natural and artificial speech processing and hearing processes, studies bandwidth extension procedures as a solution and introduces fuzzy logic for future enhancements to speech encoding. All combined, might not be a fun read, but definitely a food for thought for technologist of the social welfare genre.