System for improving speech intelligibility through high frequency compression
AssigneeQNX Software Systems Limited
InventorsPhillip Hetherington, Xueman Li
Life of this patent
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Abstract
A speech enhancement system that improves the intelligibility and the perceived quality of processed speech includes a frequency transformer and a spectral compressor. The frequency transformer converts speech signals from the time domain to the frequency domain. The spectral compressor compresses a pre-selected portion of the high frequency band and maps the compressed high frequency band to a lower band limited frequency range.
Claims21
A speech system that improves the intelligibility and quality of a processed speech, comprising:
- a frequency transformer that converts speech signals into a spectrum of frequencies;
- and
- a spectral compressor electrically coupled to the frequency transformer that compresses a pre-selected high frequency band and maps the compressed high frequency band to a lower band limited frequency range.
A speech system that improves the intelligibility of a processed speech, comprising:
- a frequency transformer that converts speech signals into its frequency domain;
- a spectral compressor coupled to the frequency transformer that compresses a pre-selected high frequency band and maps the compressed high frequency band to a lower frequency band;
- a noise detector configured to detect and estimate a level of noise present;
- and
- a gain controller configured to adjust the gain of the compressed high frequency band proportionally to the changing level of an independent and extraneous signal.
A speech system that improves the intelligibility of a processed speech, comprising:
- a frequency transformer that converts speech signals from time domain into frequency domain in real time;
- a spectral compressor coupled to the frequency transformer that compresses a pre-selected high frequency band and maps the compressed high frequency band to a lower frequency band within a telephone pass band;
- a noise detector configured to detect and measure a background noise level of speech signals;
- and
- a gain controller configured to apply a variable gain to the compressed high frequency band in relation to the level of the background noise.
Dependencies are inferred from the claim text.