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AssigneePatelhold Patentverwertungs- & Elektro-Holding AG
InventorsAlban Graf, Gustav Guanella
Estimating the term…
The known process for transmitting two or more audio signals over a single transmission channel by eliminating alternate small segments from a first signal and filling the gaps with alternate small segments of a second signal and then filling in the gaps in the received signals with repeated segments, is found to be significantly improved with respect to comprehension or understandability, etc., if the audio signals are divided into a low frequency subband and one or more high frequency subbands and if the lowest frequency subband is transmitted substantially continuously while the higher frequency subbands are segmented and transmitted as before. Processes and apparatuses for splitting the audible signals into high and low frequency subbands and for treating the signals both on the sending and receiving sides to take advantage of the above discovery are disclosed. The invention concerns a process for improving the utilization of transmission channels for sound signals as speaking or music, by which process the sound signals are divided into segments of a certain length, of which only a reduced part thereof are transmitted, and wherein the gaps in the reduced part of the signal are again filled in at the receiving end by repetition, so that the resulting signals are at least partly understandable, depending on the appropriate choice of the length of segments, whereby the transmission gaps L can be used for transmission of additional signals.
In the process for improving the utilization of transmission channels for audio signals as speech or music by which process the sound signals are divided into segments of definite length of which only a reduced part is transmitted and on reception the gaps in the reduced signal are again filled by a repetition thereof so that signals result which are at least partially understandable whereby the gaps produced in the signal transmitted can be employed for transmitting additional signals, the improvement comprising splitting the audio signal to be transmitted into at least two frequency bands including a lower frequency subband and a higher frequency subband, the lower frequency subband having a width from about 300 Hz to about 1100 Hz, transmitting the lower frequency subband in its entirety, periodically interrupting the higher frequency subband to produce short subband segments of 20-50 milliseconds length containing gaps of a time length at least equal to said segments therebetween for transmission, and, at the receiving end, reproducing the lower frequency subband and the segments of the gapped higher frequency subband and filling in the gaps in the higher frequency subband by repetition of the adjacent segments.
Apparatus for improving the utilization of transmission channels for audio signals such as speech or music, comprising a band splitter for dividing an audio signal to be transmitted into at least two subbands including a lower frequency subband having a bandwidth from about 300 H.sub.z to about 1100 H.sub.z and a higher frequency subband, said band splitter having output lines for the higher frequency subband and the lower frequency subband, said lines being subsequently connected together to form a junction, interrupter means in the line of the higher frequency subband, before said junction, for dividing the said subband into segments of a length of 20-50 milliseconds wherein at least 1/2 of the original continuous subband length is eliminated;
Dependencies are inferred from the claim text.