A method for detecting a response state of a subject's brain, wherein said method comprises: repeatedly presenting (1100) to said subject a sound stimulus to elicit a cerebral response； detecting (1200) a provoked brain response signal (20) in relation to each of said sound stimuli, wherein said provoked cerebral response signal (20) is an electrophysiological signal and said provoked cerebral response signal (20) comprises less a peak, related to a response caused by at least one neuron； determining (1300) a temporary window, said temporary window having a temporary width (21, 31, 41) that covers at least partially one of said at least one peak (32a-32g, 42a-42h) in said provoked brain response signal ； calculate (1400) an average triggered response signal (33, 43) based on said brain response signals triggered along said time window and compare said brain response signals triggered over along the time window with said response signal caused average, or calculate an average value based on one of said brain response signals caused along said time window and compare subparts of said brain response signal caused along said time window with said average value； and determine (1500) a variance and / or a volatility of the response of the at least one neuron, based on one of the two comparisons.Un método para detectar un estado de respuesta del cerebro de un sujeto, en donde dicho método comprende: presentar repetidamente (1100) a dicho sujeto un estímulo sonoro para provocar una respuesta cerebral； detectar (1200) una señal de respuesta cerebral provocada (20) en relación con cada uno de dichos estímulos sonoros, en donde dicha señal de respuesta cerebral provocada (20) es una señal electrofisiológica y dicha señal de respuesta cerebral provocada (20) comprende al menos un pico, relacionado con una respuesta provocada de al menos una neurona； determinar (1300) una ventana temporal, teniendo dicha ventana temporal una anchura temporal (21, 31, 41) que cubra al menos parci
