Phonological processing is a central concept in cognitive psychology which is used to refer to mechanisms involved in representing, accessing or manipulating information related to the sound structure of language. Phonological Processing Skills (PhPS) are thus a set of abilities that we use in many different contexts in everyday life. Due to their intimate connection to the sound structure of spoken language, there are many Deaf and Hard of Hearing children (DHH) who struggle to develop them. PhPS is further related to the acquisition and use of lexical items as well as to the building and organization of the mental lexicon, which is especially difficult for DHH children who experience periods of auditory deprivation or distortion. Additionally, PhPS are interconnected to the development of phonological decoding, a skill that is challenging to achieve for many profoundly deaf children. The importance of PhPS in a vast number of communicative and learning situations makes it important to find efficient intervention methods for many DHH children.