Efficient Neural Coding in Auditory and Speech Perception

• Published in: Trends in neurosciences (Regular ed.) 2019-01, Vol.42 (1), p.56-65
• Main Authors: Gervain, Judit, Geffen, Maria N.
• Format: Article
• Language: English
• Subjects: Acoustic Stimulation - methods; Animals; Auditory Cortex - physiology; auditory perception; Auditory Perception - physiology; Cochlear Nerve - physiology; efficient neural coding; Humans; information theory; Speech - physiology; speech perception; Speech Perception - physiology
• ISSN: 0166-2236; 1878-108X
• DOI: 10.1016/j.tins.2018.09.004

Speech has long been recognized as ‘special’. Here, we suggest that one of the reasons for speech being special is that our auditory system has evolved to encode it in an efficient, optimal way. The theory of efficient neural coding argues that our perceptual systems have evolved to encode environmental stimuli in the most efficient way. Mathematically, this can be achieved if the optimally efficient codes match the statistics of the signals they represent. Experimental evidence suggests that the auditory code is optimal in this mathematical sense: statistical properties of speech closely match response properties of the cochlea, the auditory nerve, and the auditory cortex. Even more interestingly, these results may be linked to phenomena in auditory and speech perception. Efficient neural coding may support the selectivity for speech in the auditory pathway. The auditory neuronal code matches the statistics of natural and behaviorally relevant sounds. Speech perception may rely on the same auditory coding mechanisms that facilitate efficient coding of other natural sound statistics.