A method for recognizing a concept in a signal, e.g. a speech signal, by an apparatus, the method comprising: receiving, by a receiver of the apparatus, a first signal, sampling (215, 220, 225), by the apparatus, the first signal for forming a first one-dimensional symbol sequence from the received first signal, e.g. by using vector quantization, specifying the presence of a concept in the first sequence by a concept tag, for each concept tag c k, with k varying from 1 to N c, and for each given lag l d, with d varying from 1 to N l, wherein a lag l d indicates a distance of d elements in the symbol sequence: obtaining (230, 235), by the apparatus, a transition frequency matrix T(a i, a j |l d, c k) of size Nq x Nq, wherein Nq is the number of possible symbols, by incrementing the matrix element at position i,j whenever the symbols a i and a j co-occur in the first sequence with the lag l d in the presence of the concept tag c k, obtaining, by the apparatus, a transition probability matrix P'(a i, aj|l d, c k) by normalizing the transition frequency matrix T by all possible transitions Pʹ a i, a j | l d, c k = T a i, a j | l d, c k ∑ x = 1 N q ⁢ T a i, a x | l d, c k, obtaining, by the apparatus, a tag probability matrix P(ai, a j |l d, c k) by P a i, a j | l d, c k = Pʺ a i, a j | l d, c k ∑ z = 1 N c ⁢ Pʺ a i, a j | l d, c z - 1 N c, where Pʹʹ a i, a j | l d, c k = Pʹ a i, a j | l d, c k + T a i, a j | l d, c k ∑ x = 1 N q ⁢ ∑ y = 1 N q ⁢ T a x, a y | l d, c k, receiving, by the receiver of the apparatus, a second signal, and recognizing (280, 285), by the apparatus, the presence of a concept at position t in a second symbol sequence, which is formed from the received second signal, as the concept tag c k maximizing the value of A c i t = ∑ d = 1 N l ⁢ P ⁢ s ⁢ t - l d, s t | l d, c i with i from 1 to N c. receiving, by a receiver of the apparatus, a first signal, sampling (215, 220, 225), by the apparatus, the first signal for forming a first one-dimensional symbol sequence from the received first signal, e.g. by using vector quantization, specifying the presence of a concept in the first sequence by a concept tag, for each concept tag c k, with k varying from 1 to N c, and for each given lag l d, with d varying from 1 to N l, wherein a lag l d indicates a distance of d elements in the symbol sequence: obtaining (230, 235), by the apparatus, a transition frequency matrix T(a i, a j |l d, c k) of size Nq x Nq, wherein Nq is the number of possible symbols, by incrementing the matrix element at position i,j whenever the symbols a i and a j co-occur in the first sequence with the lag l d in the presence of the concept tag c k, obtaining, by the apparatus, a transition probability matrix P'(a i, aj|l d, c k) by normalizing the transition frequency matrix T by all possible transitions Pʹ a i, a j | l d, c k = T a i, a j | l d, c k ∑ x = 1 N q ⁢ T a i, a x | l d, c k, obtaining, by the apparatus, a tag probability matrix P(ai, a j |l d, c k) by P a i, a j | l d, c k = Pʺ a i, a j | l d, c k ∑ z = 1 N c ⁢ Pʺ a i, a j | l d, c z - 1 N c, where Pʹʹ a i, a j | l d, c k = Pʹ a i, a j | l d, c k + T a i, a j | l d, c k ∑ x = 1 N q ⁢ ∑ y = 1 N q ⁢ T a x, a y | l d, c k, receiving, by the receiver of the apparatus, a second signal, and recognizing (280, 285), by the apparatus, the presence of a concept at position t in a second symbol sequence, which is formed from the received second signal, as the concept tag c k maximizing the value of A c i t = ∑ d = 1 N l ⁢ P ⁢ s ⁢ t - l d, s t | l d, c i with i from 1 to N c. obtaining (230, 235), by the apparatus, a transition frequency matrix T(a i, a j |l d, c k) of size Nq x Nq, wherein Nq is the number of possible symbols, by incrementing the matrix element at position i,j whenever the symbols a i and a j co-occur in the first sequence with the lag l d in the presence of the concept tag c k, obtaining, by the apparatus, a transition probability matrix P'(a i, aj|l d, c k) by normalizing the transition frequency matrix T by all possible transitions Pʹ a i, a j | l d, c k = T a i, a j | l d, c k ∑ x = 1 N q ⁢ T a i, a x | l d, c k, obtaining, by the apparatus, a tag probability matrix P(ai, a j |l d, c k) by P a i, a j | l d, c k = Pʺ a i, a j | l d, c k ∑ z = 1 N c ⁢ Pʺ a i, a j | l d, c z - 1 N c, where Pʹʹ a i, a j | l d, c k = Pʹ a i, a j | l d, c k + T a i, a j | l d, c k ∑ x = 1 N q ⁢ ∑ y = 1 N q ⁢ T a x, a y | l d, c k, receiving, by the receiver of the apparatus, a second signal, and recognizing (280, 285), by the apparatus, the presence of a concept at position t in a second symbol sequence, which is formed from the received second signal, as the concept tag c k maximizing the value of A c i t = ∑ d = 1 N l ⁢ P ⁢ s ⁢ t - l d, s t | l d, c i with i from 1 to N c.