| 摘要 |
1,214,011. Speech synthesizer. ELEKTRONISCHE RECHENMASCHINEN WISSENSCHAFTLICHER INDUSTRIEBETRIEBKARL-MARX-STADT VEB. 15 Dec., 1967, No. 57135/67. Heading H4R. In' a speech synthesizer a formant filter frequency and a formant filter bandwidth are controlled by the settings of respective ring counters, and a change in the sound produced by the synthesizer is obtained by keying in the new formant parameters and causing the counters to count in the appropriate direction until the counts correspond to the new formant parameters. As shown in Fig. 5 formant characteristics are fed in to set characteristic relays in 17 either in accordance with the operation of a keyboard or according to a stored programme. The characteristic relays in 17 are of the fast to operate and slow to release type so that, for the period immediately following a new formant frequency and bandwidth being fed in, both the new characteristics and the previous characteristics are available. The stored characteristics are fed to direction seeking circuits 13 and 16, for respectively the frequency and bandwidth of the formant, where the old value and the new value are compared in a logic circuit, shown in Fig. 3, to cause a bi-stable circuit 11, Fig. 3, to be set in one state, e.g. L, if the old value is greater than the new value, and into the other state, O, when the old value is less than the new value. The state of bi-stable device causes one or other of a set of gates, 19 or 20, in the counters 14 and 15, shown in detail in Fig. 2, to be enabled to cause the counter to count either forwards or backwards, in response to clock pulses from generator 10, to the required new position. The stored characteristic is also fed from the relays 17 to inhibit the appropriate one of gates 25 to 29 so that the counter stops at the appropriate count relating to the new value of the characteristic. The selection of the required settings of counters 14 and 15 to the values corresponding to the required frequency and bandwidth of the formant filter causes the enabling of a particular gate in the co-ordinate switch 18, Fig. 5, to energize the appropriate point in a potential field 12 which comprises a conductive sheet, or an electrolytic tank having a number of output electrodes connected to the modulators of a conventional channel vocoder. The potential distribution on the electrodes depends on the precise injection point, or points, and thus controls the frequency and bandwidth of the formants synthetized by the vocoder. |
