Voice conversion is a technique for modifying speech acoustics, converting non-/para- linguistic information to any form we want while preserving the linguistic content. One of the most popular approaches to voice conversion is based on statistical processing, which is capable of extracting complex conversion functions from a parallel speech data set consisting of utterance pairs of the source and the target voices. Although this technique was originally studied in the context of speaker conversion, which converts the voice of a certain speaker to sound like that of another speaker, it has great potential to achieve various applications beyond speaker conversion. This talk will briefly review the recent progress of statistical voice conversion techniques, and will highlight a technique to achieve a lower conversion delay. Finally this talk will show some potential applications of real-time statistical voice conversion to augment our speech production, making it possible to enhance human-to-human speech communication beyond several constraints.