Method and circuit arrangement for adjusting the level or dynamic range of an audio signal
DCFirst Claim
1. A method for adjusting the level and/or dynamic range of a first audio signal (s1a) containing noise and information for reproduction in a space containing acoustic noise, comprising the steps of:
- measuring the level of said first audio signal to obtain a first measured value (p1),measuring the noise level of said first audio signal to obtain a second measured value (p2),measuring the acoustic noise level of said space to attain a third measured value (p3), andadjusting the level and/or dynamic range of said first audio signal in accordance with said first, second, and third measured values (p1,p2,p3).
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Abstract
The invention relates to a method and a circuit arrangement for adjusting the level and/or dynamic range of an audio signal in a transmission system and particularly in a mobile station. According to the invention, the level of acoustic noise in the environment of a terminal (10, 12) and the level and noise level of a received signal are measured (123) and the level and/or dynamic range of the reproduced signal are adjusted (121, 122) according to the results from said measurements. The solution according to the invention helps reduce the effect of noise in the signal transmitted on the transmission channel (11) and of the acoustic noise in the environment of the terminal (12) on the intelligibility of the reproduced information.
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Citations
34 Claims
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1. A method for adjusting the level and/or dynamic range of a first audio signal (s1a) containing noise and information for reproduction in a space containing acoustic noise, comprising the steps of:
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measuring the level of said first audio signal to obtain a first measured value (p1), measuring the noise level of said first audio signal to obtain a second measured value (p2), measuring the acoustic noise level of said space to attain a third measured value (p3), and adjusting the level and/or dynamic range of said first audio signal in accordance with said first, second, and third measured values (p1,p2,p3). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for adjusting the dynamic range and/or level of a second audio signal (s2a) picked up from a space, comprising the steps of:
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measuring the acoustic noise level of said space from said second audio signal (s2a) to obtain said third measured value (p3), measuring the continuous power level of said second audio signal (s2a) to obtain a fourth measured value (p4), adjusting the level and/or dynamic range of said second audio signal (s2a) in accordance with said third measured value (p3) and fourth measured value (p4). - View Dependent Claims (19)
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20. A circuit arrangement for adjusting the level and/or dynamic range of a first audio signal (s1a) reproduced in a space, comprising:
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means (303) for measuring the level of the first audio signal (s1a) to obtain a first measured value (p1), means (303) for measuring the noise level in the first audio signal (s1a) to obtain a second measured value (p2), means (313) for measuring the noise level in said space to obtain a third measured value (p3), and means (304,
306) for adjusting the level and/or dynamic range of the first audio signal (s1a) in accordance with said first, second and third measured values (p1,p2,p3). - View Dependent Claims (21, 22, 23, 24)
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25. A circuit arrangement for adjusting the level and/or dynamic range of a second audio signal (s2a) picked up from a space, comprising
means (312,313) tor measuring the ambient noise level of said space from said second audio signal to obtain said third measured value (p3), means (312,313) for measuring the level of said second audio signal and to obtain a fourth measured value (p4), and means (122, 314, 316) for adjusting the level and/or dynamic range of the second audio signal (s2a) in accordance with said third measured value (p3) and fourth measured value (p4).
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27. A method for adjusting the level and/or dynamic range of a first audio signal (s1a) containing noise and information for reproduction in a space containing acoustic noise, comprising the steps of:
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measuring the level of said first audio signal to obtain a first measured value (p1), measuring the noise level of said first audio signal to obtain a second measured value (p2), measuring the acoustic noise level of said space to obtain a third measured value (p3), and adjusting the level and/or dynamic range of said first audio signal in accordance with said first, second and third measured values (p1, p2, p3) by expanding the signal, when the signal level value is below a first threshold value (g), compressing the signal, when the signal level value is above a second threshold value (i), and processing the signal in a substantially linear manner, when the signal level value is between said first and second threshold values (g,i). - View Dependent Claims (28, 30)
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29. A method for adjusting the dynamic range and/or level of a second audio signal (s2a) picked up from a space, comprising the steps of:
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measuring the acoustic noise level of said space from said second audio signal (s2a) to obtain said third measured value (p3), measuring the continuous power level of said second audio signal (s2a) to obtain a fourth measured value (p4), adjusting the level and/or dynamic range of said second audio signal (s2a) according to said third measured value (p3) and fourth measured value (p4) by expanding the signal, when the signal level value is below a first threshold value (g), compressing the signal, when the signal level value is above a second threshold value (i), and processing the signal in a substantially linear manner, when the signal level value is between said two threshold values (g,i).
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31. A circuit arrangement for adjusting the level and/or dynamic range of a first audio signal (s1a) reproduced in a space, comprising:
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means (303) to measure the level of the first audio signal (s1a) to obtain a first measured value (p1), means (303) to measure the noise level in the first audio signal (s1a) to obtain a second measured value (p2), means (313) to measure the noise level in said space to obtain a third measured value (p3), and means (304,
306) to adjust the level and/or dynamic range of the first audio signal (s1a) according to said first, second and third measured values (p1,p2,p3) comprising;means for expanding the signal, when the signal level value is below a first threshold value (g), means for compressing the signal, when the signal level value is above a second threshold value (i), and means for processing the signal in a substantially linear manner, when the signal level value is between said two threshold values (g,i). - View Dependent Claims (32)
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33. A circuit arrangement for adjusting the level and/or dynamic range of a second audio signal (s2a) picked up from a space, comprising:
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means (312,313) to measure the ambient noise level of said space from said second audio signal to obtain said third measured value (p3), means (312,313) to measure the level of said second audio signal and to obtain a fourth measured value (p4), and means (122,314,316) to adjust the level and/or dynamic range of the second audio signal (s2a) according to said third measured value (p3) and fourth measured value (p4) comprising; means for expanding the signal, when the signal level value is below a first threshold value (g), means for compressing the signal, when the signal level value is above a second threshold value (i), and means for processing the signal in a substantially linear manner, when the signal level value is between said two threshold values (g,i). - View Dependent Claims (34)
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Specification