| 摘要 |
The characteristic values are obtained from the signal to be verified, e.g. in the case of a voice signal the total energy in the individual frequency spectrum ranges, and these characteristic values are quantified. The frequency with which the individual partial ranges of the quantified characteristic values occur is found during a sampling phase, and these frequencies are stored. In the test phase, the signal is analyzed in the same way and the stored frequencies of the partial ranges into which the characteristic values of the signal to be verified have fallen are multiplied and compared with a threshold. In an arrangement for implementing the method, there is a characteristic store with a store address for a multi-digit binary number for each partial range of each characteristic. This store is addressed by a counter, the positions of which are allocated to the individual characteristics or spectrum ranges of the voice signal, and by the numbers of the partial ranges of the characteristics found during the analysis into which the characteristic values of the signal to be analyzed have fallen. In the sampling phase the content of each addressed store address is raised by 1 and in the test phase the frequencies obtained in the store addresses addressed are multiplied together. When a voice signal is processed for verification of the speaker, with the stepwise formation of the long-term spectrum, the intermediate values are compared with a range limit of a partial range read out from a range limit store and increased by 1 on exceeding a number allocated to this characteristic in an intermediate store. In this manner, it is possible at the end of the voice signal, immediately and without any further processing steps to obtain the quantified characteristics in the form of the numbers of the partial ranges which can then be used to increase the frequencies in the characteristic store. A summation over all spectrum values is made to standardize the incoming voice signals. Subsequently, to all spectrum values is added a given fraction of their value, performed in the simplest manner by position shifting, until the sum of all spectrum values exceeds a predetermined constant. Thus the determination of the quantified characteristics or the partial range sums is immediately effective. The multiplication of the frequencies may be replaced by the addition of the logarithmic frequencies. |
