Abstract: A background sound sending side multiplexes and sends, in a multiplexer, uttered encoded speech data generated in a speech sending section and encoded background sound data outputted from a background sound storing section. Simultaneously, a background sound reproducing section, reproduces encoded background sound data and reproduced background sound signal is superposed on received speech in a receiving section and outputted from a receiver. A background sound receiving side demultiplexes, in a demultiplexer, received multiplexed data into received encoded speech data and encoded background sound data which are decoded in the receiving section and the background sound reproducing section respectively, and in the receiving section, a sound in which received speech and background sound are superposed is outputted from a receiver.

Abstract: A background sound sending side multiplexes and sends, in a multiplexer, uttered encoded speech data generated in a speech sending section and encoded background sound data outputted from a background sound storing section. Simultaneously, a background sound reproducing section, reproduces encoded background sound data and reproduced background sound signal is superposed on received speech in a receiving section and outputted from a receiver. A background sound receiving side demultiplexes, in a demultiplexer, received multiplexed data into received encoded speech data and encoded background sound data which are decoded in the receiving section and the background sound reproducing section respectively, and in the receiving section, a sound in which received speech and background sound are superposed is outputted from a receiver.

Abstract: This invention relates to a process for selectively recovering vanadium from spent catalysts which were used in hydrodesulufurization, hydrodemetallization, etc. of heavy oils until metals in said heavy oils accumulated thereon. More particularly, it relates to a process for recovering vanadium, and if desired, vanadium along with nickel from spent catalysts in such a way that said spent catalysts are chlorinated with chlorinating agent(s) at a temperature below 600.degree. C. without being subjected to calcination so as to convert almost all the vanadium compounds to vanadium tetrachloride which is recovered in the form of a gas, including the chlorination of nickel compounds of nickel chloride which can also be recovered as such by solvent extraction.