After cochlear implantation, post-lingually deafened listeners are able to (partially) adapt to new patterns with electric hearing relative to previous patterns developed with acoustic hearing, typically within the first 3-6 months of cochlear implant use. Experienced listeners must also adapt to new electrical stimulation patterns provided by updated processors, strategies and/or changes to processor parameters. Thus, considerable auditory plasticity exists in cochlear implant listeners, even after years of experience with their device. While "passive" learning may allow for some adaptation, "active" auditory training may better exploit listeners' auditory plasticity. There is much evidence in studies that auditory training can improve speech and music perception, even after years of experience with a device and/or signal processing strategy. Researchers have consistently shown significant improvements in speech and music perception with moderate amounts (~10 hours) of computer- based training that provides audio-visual feedback (Fu et al., 2005; Galvin et al., 2007, 2009; Stacey and Summerfield, 2007, 2008; Stacey et al., 2010; Oba et al., 2011; Fu et al., 2012; Galvin et al., 2012). In these studies, speech recognition performance improved with training even after long-term experience with their device, and after extended baseline testing to minimize "procedural learning" effects. Training often generalized to untrained tasks, and performance gains were largely retained one month or more after training was stopped. Recent work by Oba et al. (2012) further showed that the improved auditory performance was due to the targeted auditory training, rather than generally improved attention and/or memory. In many of these studies, mean performance improved by 15-20 points after training. Indeed, as advances in CI technology seem to be reaching a point of diminishing returns, auditory training may provide the most cost-effective approach to maximize the benefit of cochlear implantation. Advances in computer technology have contributed greatly to the latest-generation cochlear implant and/or hearing aid technology. These advances also have allowed for the development of important rehabilitation tools, which may ultimately provide the greatest benefit for those hearing impaired who have difficulty with their device. Motivation is an important factor in successful patient outcomes. With the right tools and resources for auditory rehabilitation, cochlear implant and/or hearing aid users may find the necessary motivation and momentum to get the most from their implant and/or hearing aid.

While recent findings suggest great promise for auditory training in cochlear implant and/or hearing aid users, many challenges remain in terms of developing effective and efficient training protocols and materials. • The generalization of improvement to different speech tests and listening environments; • "Real-world" benefits are, of course, the ultimate goal of auditory training; • The financial cost occurred with auditory training; • The effort associated with CI patients' auditory training. How long must users train before realizing tangible returns on their efforts? It is critical to develop efficient and effective training programs with advanced protocols and comprehensive materials to minimize the time commitment while maximize training outcomes. It is important to develop training programs with advanced protocols and comprehensive materials that will provide rapid improvement over a relatively short time period, and that training with one protocol/material will generalize to the many listening environments that cochlear implant or hearing aid listeners may encounter in the real world. After almost 20 years’ of extensive research at House Research Institute supported by National Institute of Health, Emily Shannon Fu Foundation (Formerly TigerSpeech Technology) have developed computer-assisted speech training (CAST) technology for auditory rehabilitation based on advanced computer technology, signal processing, psychoacoustic, linguistic, and hand-on working experience with hundred of cochlear implant and/or hearind aid users. CAST technology has been successfully transformed into commercial products. Angel Sound is the latest and will be the exclusive products based on the CAST technology in the future. Angel Sound provides many advanced features to ensure the effectiveness and efficiency of the program, which are shown as follows. • Interactive, self-directed modules for adults and teens at all skill levels; • Comprenhensive training materials, including over 10,000 sounds, words, and sentences; • Advanced training protocols, including phonetic contrast, adaptive noise, keyword-in-sentence training protocols etc; • Signal processing to mimic the real-world listening conditions, such as background noise, telephone speech; • Extensive scientific verification for the training protocols and mateirlas used in the Angel Sound program

Angel series of auditory rehabilitation and assessment tools were developed by Dr. Qian-Jie Fu and Xiaosong Wang after losing their beloved daughter, Emily Fu. Angel Sound TM and other software will be provided free of charge by Emily Fu Foundation, which is to honor their dearest daughter Emily, her beautiful, smart, happy life though short brought a message to us that “life on earth is temporary no matter how long you live, but love is forever, and helping others is life’s true meaning”.