The SpiN project stands at the frontier between experimental linguistics and cognitive neuroscience research. It aims at achieving a critical break-through in the domain of speech-in-noise comprehension by setting up a dedicated interdisciplinary research team. The comprehension of speech in noise is a complex task even for normal hearing people and it is the primary and principal problem experienced by people facing hearing loss or auditory processing disorders. Under ecological conditions, a speech signal scarcely ever reaches the ear without any interfering noise. We will study our capacity to understand speech by relying on the interaction between auditory processing and the specialized cognitive processes involved in speech comprehension and degraded speech restoration. The originality of our approach is to investigate natural speech comprehension both from a language-based and an auditory-driven perspective, using the same synergy as is brought into play when those systems work to achieve speech comprehension. To this end, several experimental techniques including behavioural assessment, electrophysiological measurements and neuroimaging will be used to conduct tests in different target populations (normal hearing participants, hearing impaired and speech processing impaired patients). A systematic evaluation of auditory performances will be done and compared to results of all experiments carried out. In all the results we will highlight the inter-individual variability observed in speech comprehension performances. This will allow us to unravel the links between sensory processes and speech intelligibility and obtain valuable information for the understanding of the neurocognitive processes underlying the comprehension of speech in general. Understanding speech restoration in ecological situations constitutes a challenge that scientists are bound to face as it is becoming such an important societal issue given the omnipresence of noise in modern societies.