| 摘要 |
1,059,802. Vocoder. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 29, 1965 [April 6, 1964], No. 13167/65. Heading H4R. Digital data representing time multiplexed spectrum channel signals and excitation function signals of a channel vocoder are supplied from a data processing system EDV to a commutator switch S which feeds the individual channel signals to their respective synthesis channels 1 to n, each of which contains a digital-to-analogue converter DAW and the appropriate frequency filter FS. Switch S operates to feed. one sample per channel during each excitation function period, and if this sample is applied to. the filter as an amplitude modulated pulse the usual channel modulator becomes redundant. The various channel signals are added, amplified, and reproduced by a loud-speaker. The plurality of digital to analogue converters, one in each spectrum channel, may be replaced by one in the common line to the switch S. A buffer store may also be included in the common line to the switch S, Fig. 4 (not shown). |
