Emphasis (telecommunications)
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It has been suggested that Pre-emphasis be merged into this article or section. (Discuss) Proposed since June 2011. |
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It has been suggested that Deemphasis be merged into this article or section. (Discuss) Proposed since June 2011. |
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This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2010) |
In FM transmission, emphasis is the intentional alteration of the amplitude-vs.-frequency characteristics of the signal to reduce adverse effects of noise in a communication system.
The high-frequency signal components are emphasized to produce a more equal modulation index for the transmitted frequency spectrum, and therefore a better signal-to-noise ratio for the entire frequency range.
The whole system of preemphasis and deemphasis is called emphasis. The frequency curve is decided by special time constants. The cutoff frequency can be calculated from that.
Emphasis is commonly used in audio digital recording, record cutting and in FM radio transmission.