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US 5,099,498 AGranted
Method for suppressing quantization noises superimposed on a sinusoidal audible tone transmitted in a digital telecommunications exchange system
AssigneeSiemens Aktiengesellschaft
InventorsWerner Nagler, Hans-Werner Rudolf, Monika Stadler
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Abstract
A harmonic tone having an amplitude which is significantly lower than a fundamental audible tone is superimprosed on the audible tone to drown out quantization noises for audible tones transmitted in digital telecommunications exchange systems.
Claims4
In a method for transmitting an audible tone in a digital telecommunications system wherein the audible tone includes quantization noise which is disruptive of the audible tone, the improvement comprising the steps of:
- generating an audible tone which includes quantization noise;
- separately generating a harmonic tone of the audible tone at an amplitude significantly lower than the amplitude of the audible tone and sufficient high to mask said quantization noise;
- and
- additively superimposing the separately generated harmonic tone on the audible tone for transmission therewith.
1 more element
Dependencies are inferred from the claim text.