AUDIO SIGNAL PROCESSING METHOD AND AUDIO SIGNAL PROCESSING DEVICE

Abstract

An audio signal processing procedure comprises obtaining an audio signal and a detected signal; obtaining a frequency range, wherein the frequency range includes an upper cutoff frequency and a lower cutoff frequency; calculating a first sound pressure difference between the audio signal filtered at the upper cutoff frequency and the audio signal filtered at the lower cutoff frequency; calculating a second sound pressure difference between the detected signal filtered at the upper cutoff frequency and the detected signal filtered at the lower cutoff frequency; generating a compensation value according to the first sound pressure difference and the second sound pressure difference; and adjusting the audio signal according to the compensation value.Based on the first sound pressure difference corresponding to the audio signal and the second sound pressure difference corresponding to the detected signal, the compensation value is generated to compensate for the audio signal in order to prevent sound attenuation and amplification.

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] This application claims priority over Chinese utility model application No. CN202422320448.3, filed on September 23, 2024, pursuant to 35 USC. §119(e), the entire contents of which are hereby incorporated by reference. TECHNICAL AREA

[0002] The present invention relates to sound processing and in particular to an audio signal processing method and an audio signal processing device for avoiding sound attenuation and amplification. BACKGROUND OF THE INVENTION

[0003] Currently, the rapid development of technology is improving the quality of daily life, increasing user demand for sound quality, and consequently, the quality of audio devices is also improving. Headphones are a common audio device. Wireless earbuds are popular due to their portability, but the shape of earbuds is not suitable for all ear shapes, and the environment in which they are used can cause sound attenuation and amplification, negatively impacting the sound quality. SUMMARY OF THE INVENTION

[0004] According to the foregoing, the present invention provides an audio signal processing method and an audio signal processing device for solving the problem of sound attenuation and amplification.

[0005] According to the preceding problem, the present invention provides an audio signal processing method comprising: obtaining an audio signal and a detected signal; obtaining a frequency range, wherein the frequency range includes an upper cutoff frequency and a lower cutoff frequency; calculating a first sound pressure difference between the audio signal filtered at the upper cutoff frequency and the audio signal filtered at the lower cutoff frequency; calculating a second sound pressure difference between the detected signal filtered at the upper cutoff frequency and the detected signal filtered at the lower cutoff frequency; generating a compensation value according to the first sound pressure difference and the second sound pressure difference; and adjusting the audio signal according to the compensation value.

[0006] In one embodiment of the present invention, obtaining the frequency range comprises: filtering the audio signals to obtain a first audio signal with respect to the upper cutoff frequency and a second audio signal with respect to the lower cutoff frequency; and filtering the detected signal to obtain a first detected signal with respect to the upper cutoff frequency and a second detected signal with respect to the lower cutoff frequency.

[0007] In one embodiment of the present invention, calculating a first sound pressure difference corresponding to the upper cutoff frequency and the lower cutoff frequency of the audio signal comprises: obtaining a first sound pressure value corresponding to the upper cutoff frequency and a second sound pressure value corresponding to the lower cutoff frequency according to the first audio signal and the second audio signal, and performing a subtraction operation on the first sound pressure value and the second sound pressure value to generate the first sound pressure difference.

[0008] In one embodiment of the present invention, calculating the second sound pressure difference, which corresponds to the upper cutoff frequency and the lower cutoff frequency of the detected signal, comprises: obtaining a first detected sound pressure value corresponding to the upper cutoff frequency and a second detected sound pressure value corresponding to the lower cutoff frequency, based on the first detected signal and the second detected signal; and performing a subtraction operation on the first detected sound pressure value and the second detected sound pressure value to generate the second sound pressure difference.

[0009] In one embodiment of the present invention, generating the compensation value according to the first sound pressure difference and the second sound pressure difference comprises: performing a subtraction operation on the first sound pressure difference and the second sound pressure difference to generate a transient sound pressure value; performing an addition operation on the transient sound pressure value and a previous sound pressure value to generate a current sound pressure value; and generating the compensation value according to the current sound pressure value.

[0010] In one embodiment of the present invention, generating the compensation value according to the first sound pressure difference and the second sound pressure difference comprises: performing a subtraction operation on the first sound pressure difference and the second sound pressure difference to generate a transient sound pressure value; performing an addition operation on the transient sound pressure value and a previous sound pressure value to generate a current sound pressure value; receiving an external operation signal and generating a dynamic target sound pressure value according to the external operation signal; setting the current sound pressure value according to the dynamic target sound pressure value; and generating the compensation value according to the current sound pressure value.

[0011] In one embodiment of the present invention, the audio signal processing method further comprises smoothing the first sound pressure difference and the second sound pressure difference.

[0012] According to the preceding problem, the present invention provides an audio signal processing device comprising a loudspeaker, a microphone, and a processor. The loudspeaker is configured to reproduce an audio signal. The microphone is configured to generate a detected signal.The processor is connected to the speaker and the microphone, and the processor performs the following steps: obtaining a frequency range, where the frequency range includes an upper cutoff frequency and a lower cutoff frequency; calculating a first sound pressure difference between the audio signal filtered at the upper cutoff frequency and the audio signal filtered at the lower cutoff frequency; calculating a second sound pressure difference between the detected signal filtered at the upper cutoff frequency and the detected signal filtered at the lower cutoff frequency; generating a compensation value according to the first and second sound pressure differences; and adjusting the audio signal according to the compensation value.

[0013] In one embodiment of the present invention, the processor comprises a high-pass filter and a low-pass filter, and the obtaining of the frequency range by the processor comprises: filtering the audio signal through the high-pass filter and the low-pass filter to obtain a first audio signal with respect to the upper cutoff frequency and a second audio signal with respect to the lower cutoff frequency, wherein the high-pass filter and the low-pass filter each filter the detected signal according to a reference frequency to obtain a first detected signal with respect to the upper cutoff frequency and a second detected signal with respect to the lower cutoff frequency.

[0014] In one embodiment of the present invention, the calculation of a first sound pressure difference between the audio signal filtered at the upper cutoff frequency and the audio signal filtered at the lower cutoff frequency by the processor comprises: the processor obtains, according to the first audio signal and the second audio signal, a first sound pressure value corresponding to the upper cutoff frequency and a second sound pressure value corresponding to the lower cutoff frequency; and the processor performs a subtraction operation on the first sound pressure value and the second sound pressure value to generate the first sound pressure difference.

[0015] In one embodiment of the present invention, the calculation of a second sound pressure difference between the detected signal filtered at the upper cutoff frequency and the detected signal filtered at the lower cutoff frequency by the processor comprises: the processor obtains, according to the first detected signal and the second detected signal, a first detected sound pressure value corresponding to the upper cutoff frequency and a second detected sound pressure value corresponding to the lower cutoff frequency; and the processor performs a subtraction operation on the first detected sound pressure value and the second detected sound pressure value to generate the second sound pressure difference.

[0016] In one embodiment of the present invention, the processor comprises a memory and a low-shelf filter, wherein the memory stores a previous sound pressure value and the processor generates the compensation value according to the first sound pressure difference and the second sound pressure difference: the processor performs a subtraction operation on the first sound pressure difference and the second sound pressure difference to generate a transient sound pressure value; the processor performs an addition operation on the transient sound pressure value and the previous sound pressure value to generate a current sound pressure value; and the low-shelf filter generates the compensation value according to the current sound pressure value.

[0017] In one embodiment of the present invention, the processor comprises a memory and a depth cowtail filter, wherein the memory stores a previous sound pressure value and the processor generates the compensation value according to the first sound pressure difference and the second sound pressure difference by: the processor performs a subtraction operation on the first sound pressure difference and the second sound pressure difference to generate a transient sound pressure value; the processor performs an addition operation on the transient sound pressure value and the previous sound pressure value to generate a current sound pressure value; the processor receives an external operation signal and generates a dynamic target sound pressure value according to the external operation signal; the processor sets the current sound pressure value according to the dynamic target sound pressure value;and the low-frequency cowtail filter generates a compensation value according to the set current sound pressure level.

[0018] In one embodiment of the present invention, the processor further performs a smoothing process on the first sound pressure difference and the second sound pressure difference.

[0019] In summary, in the audio signal processing method and audio signal processing device of the present invention, based on the first sound pressure of the audio signal corresponding to the loudspeaker and the second sound pressure difference of the detected signal corresponding to the microphone, the compensation value is generated to compensate the audio signal in order to prevent sound attenuation and amplification.

[0020] The above description is only an overview of the technical solution of the present invention. To better understand the technical means of the present invention and to facilitate its implementation according to the description, the present invention is described in detail below with embodiments of the present invention and with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a block diagram of an audio signal processing device according to an embodiment of the present invention. Fig. Figure 2 is a block diagram of a processor according to an embodiment of the present invention. Fig. Figure 3 is a flowchart of an audio signal processing method according to an embodiment of the present invention. Fig. Figure 4 is a flowchart for calculating a first sound pressure difference in the audio signal processing method according to an embodiment of the present invention. Fig. Figure 5 is a flowchart for calculating a second sound pressure difference in the audio signal processing method according to an embodiment of the present invention. Fig. Figure 6A is a flowchart for generating a compensation value in the audio signal processing method according to an embodiment of the present invention. Fig. Figure 6B is a flowchart for generating the compensation value in the audio signal processing method according to a further implementation of the present invention. Fig. Figure 7 is a flowchart of the audio signal processing method according to a further embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] The implementation of the present invention is described below with reference to specific embodiments, and persons who have ordinary technical knowledge in the field can easily understand the advantages and effects of the present invention from the contents disclosed in this detailed description.

[0022] It should be noted that the embodiments of the present invention and the features of these embodiments can be combined without contradiction. The present invention is described in detail below with reference to the drawings and in conjunction with exemplary embodiments. To enable the person skilled in the art to better understand the present invention, the technical scheme of the embodiments of the present invention is clearly and completely described below in conjunction with the drawings. It is obvious that the described embodiments are only illustrations of part of the present invention, not all embodiments. According to the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative work fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first," "second," etc., in the description and claims of the present invention and in the drawings mentioned above are used to distinguish similar objects and are not intended to describe a specific order or sequence. Furthermore, the terms "including" and "with," and any variation thereof, are intended to encompass non-exclusive inclusions, such as a process, method, system, product, or apparatus comprising a number of steps or elements, and are not intended to limit the steps or elements that are clearly listed, which may include other steps or elements that are not clearly listed or are inherent in such processes, methods, products, or equipment.

[0024] Fig. Figure 1 is a block diagram of an audio signal processing device according to an embodiment of the present invention. As shown in Fig. As shown in Figure 1, the audio signal processing device comprises a loudspeaker 10, a microphone 20, and a processor 30. The audio signal processing device can be, but is not limited to, a headset or a wireless earphone. The loudspeaker 10 is configured to reproduce an audio signal. The microphone 20 is configured to generate a detected signal. The processor 30 is connected to the loudspeaker 10 and the microphone 20 to receive the audio signal and the detected signal. The digital signal processing and the generation of compensation values ​​performed by the processor 30 on the audio signal and the detected signal are described in the section on the audio signal processing procedure.

[0025] Specifically, the audio signal is reproduced via the loudspeaker 10 to generate sound (e.g., a song or the sound of a musical instrument), and the microphone 20 is adjacent to the loudspeaker 10 and generates a detected signal corresponding to the sound. The processor 30 can be a central processing unit, a graphics processing unit, or another type of processor, the foregoing being merely examples and not limiting the scope set out in this application.

[0026] Furthermore, the audio signal processing device is wirelessly connected to an external electronic device to receive an external operating signal. This external electronic device could be, for example, a mobile phone or a tablet computer. The processor 30 adjusts the current sound pressure level according to the external operating signal. The steps of the processor 30 that adjust the current sound pressure level according to the external operating signal are described in the section on the audio signal processing procedure.

[0027] Fig. Figure 2 is a block diagram of a processor according to an embodiment of the present invention. As in Fig. As shown in Figure 2, the processor 30 comprises a high-pass filter 31, a low-pass filter 32, a memory 33, and a low-frequency shelving filter 34. The high-pass filter 31 filters the low-frequency portion of the audio signal and the detected signal, while allowing the high-frequency portion to pass. The low-pass filter 32 filters the high-frequency portion of the audio signal and the detected signal, while allowing the low-frequency portions to pass. The memory 33 stores previous sound pressure values. The low-frequency shelving filter 34 compensates for the frequency response of the low-frequency portion of the audio signal.

[0028] In another embodiment, the processor 30 comprises a memory 33 and a peaking filter. The memory 33 stores digital transfer functions corresponding to the high-pass filter 31 and the low-pass filter 32. The processor 30 retrieves these digital transfer functions from the memory 33 and applies them to filter the audio signal and the detected signal, thus performing the functions of the high-pass filter 31 and the low-pass filter 32. The peaking filter compensates for the frequency response of the low-frequency portion of the audio signal.

[0029] Fig. Figure 3 is a flowchart of an audio signal processing method according to an embodiment of the present invention. As in Fig. As shown in section 3, the audio signal processing procedure comprises steps S11 to S16. This is shown in Fig. The three audio signal processing methods shown can be compared to those in Fig. 1 and Fig. The audio signal processing device shown in section 2 may be adapted, but is not limited to it. The following example describes steps S11 to S16 by illustrating the operation of the device shown in Fig. The audio signal processing device shown in 1 is used for illustration purposes.

[0030] Step S11: Receiving an audio signal and a detected signal. As mentioned above, the processor 30 is configured to receive the audio signal and the detected signal from the speaker 10 and the microphone 20.

[0031] Step S12: Obtaining a frequency range, where the frequency range includes an upper cutoff frequency and a lower cutoff frequency.

[0032] In one embodiment, the high-pass filter 31 filters the audio signal according to a reference frequency, filtering out the low-frequency portion of the audio signal that is lower than the reference frequency and retaining the high-frequency portion of the audio signal that is higher than the reference frequency as a first audio signal. The low-pass filter 32 filters the audio signal according to the reference frequency, filtering out the high-frequency portion of the audio signal that is higher than the reference frequency and retaining the low-frequency portion of the audio signal that is lower than the reference frequency as a second audio signal. In other words, the first audio signal is a high-frequency signal and the second audio signal is a low-frequency signal. The processor 30 obtains the upper and lower cutoff frequencies according to the first and second audio signals.

[0033] The high-pass filter 31 filters the detected signal according to the reference frequency, filtering out the low-frequency portion of the detected signal that is lower than the reference frequency and retaining the high-frequency portion of the detected signal that is higher than the reference frequency as a first detected signal. The low-pass filter 32 filters the detected signal according to the reference frequency, filtering out the high-frequency portion of the detected signal that is higher than the reference frequency and retaining the low-frequency portion of the detected signal that is lower than the reference frequency as a second detected signal. In other words, the first detected signal is a high-frequency signal and the second detected signal is a low-frequency signal. The processor 30 obtains the upper and lower cutoff frequencies according to the first and second detected signals.

[0034] In another embodiment, the processor 30 receives the digital transfer functions corresponding to the high-pass filter 31 and the low-pass filter 32 from the memory 33 and applies the digital transfer functions corresponding to the high-pass filter 31 and the low-pass filter 32 to perform signal filtering on the audio signal and the detected signal in order to obtain a first audio signal, a second audio signal, a first detected signal and a second detected signal.

[0035] Step S13: Calculating a first sound pressure difference between the audio signal filtered at the upper cutoff frequency and the audio signal filtered at the lower cutoff frequency. In particular, the processor 30 first receives a first sound pressure value of the audio signal at an upper cutoff frequency and a second sound pressure value of the audio signal at a lower cutoff frequency and performs a subtraction operation on the first sound pressure value and the second sound pressure value to generate the first sound pressure difference.

[0036] Fig. Figure 4 is a flowchart for calculating a first sound pressure difference in the audio signal processing method according to an embodiment of the present invention. As in Fig. As shown in Figure 4, the step of calculating the first sound pressure difference corresponding to the upper and lower cutoff frequencies of the audio signal comprises steps S131 to S132. The following example describes steps S131 to S132 by illustrating the operation of the Fig. 1 and Fig. The audio signal processing device shown in section 2 is used for illustration purposes.

[0037] Step S131: Based on the first audio signal and the second audio signal, a first sound pressure value corresponding to the upper cutoff frequency and a second sound pressure value corresponding to the lower cutoff frequency are obtained. Specifically, the processor 30 obtains a first audio sound pressure value corresponding to the upper cutoff frequency from the first audio signal, and obtains a second sound pressure value corresponding to the lower cutoff frequency from the second audio signal.

[0038] Step S132: Performing a subtraction operation on the first sound pressure value and the second sound pressure value to generate the first sound pressure difference. Specifically, processor 30 subtracts the first audio signal sound pressure value from the second audio signal sound pressure value to generate a first sound pressure difference.

[0039] Step S14: Calculating a second sound pressure difference between the detected signal filtered at the upper cutoff frequency and the detected signal filtered at the lower cutoff frequency. In particular, the processor 30 first receives a first detected sound pressure value of the detected signal filtered at the upper cutoff frequency and a second detected sound pressure value of the audio signal filtered at the lower cutoff frequency, and performs a subtraction operation on the first detected sound pressure value and the second detected sound pressure value to generate the second sound pressure difference.

[0040] Fig. Figure 5 is a flowchart for calculating a second sound pressure difference in the audio signal processing method according to an embodiment of the present invention. As in Fig. As shown in Figure 5, the step of calculating the second sound pressure difference, corresponding to the upper and lower cutoff frequencies of the detected signal, comprises steps S141 to S143. The following example describes steps S141 to S143 by illustrating the operation of the Fig. 1 and Fig. The audio signal processing device shown in section 2 is used for illustration purposes.

[0041] Step S141: Based on the first detected signal and the second detected signal, a first detected sound pressure value corresponding to the upper cutoff frequency and a second detected sound pressure value corresponding to the lower cutoff frequency are obtained. In particular, based on the upper cutoff frequency, the processor 30 obtains a first detected sound pressure value corresponding to the upper cutoff frequency from the first detected signal, and, based on the lower cutoff frequency, it obtains the second detected sound pressure value corresponding to the lower cutoff frequency from the second detected signal.

[0042] Step S142: Performing a subtraction operation on the first detected sound pressure value and the second detected sound pressure value to generate the second sound pressure difference. Specifically, processor 30 subtracts the first detected sound pressure value from the second detected sound pressure value to generate a second sound pressure difference.

[0043] Steps S13 and S14 each calculate the sound pressure difference between the audio signal and the detected signal, which was filtered at the upper and lower cutoff frequencies, respectively. Processor 30 can execute steps S13 and S14 simultaneously to generate the first and second sound pressure differences synchronously. Alternatively, processor 30 can execute steps S13 and S14 separately to generate the first and second sound pressure differences.

[0044] Step S15: Generating a compensation value according to the first sound pressure difference and the second sound pressure difference.

[0045] In one implementation, the processor performs 30 calculations on the first sound pressure difference and the second sound pressure difference to generate a current sound pressure value, and generates a compensation value according to the current sound pressure value.

[0046] Fig. Figure 6A is a flowchart for generating a compensation value in the audio signal processing method according to an embodiment of the present invention. As shown in Fig. As shown in Figure 6A, the step of generating a compensation value according to the first sound pressure difference and the second sound pressure difference comprises steps S151A to S153A. The following example describes steps S151A to S153A by illustrating the operation of the Fig. 1 and Fig. The audio signal processing device shown in section 2 is used for illustration purposes.

[0047] Step S151A: Performing a subtraction operation on the first sound pressure difference and the second sound pressure difference to generate a transient sound pressure value. Specifically, processor 30 subtracts the first sound pressure difference from the second sound pressure difference to generate a transient sound pressure value.

[0048] Step S152A: Performing an addition operation on the transient sound pressure value and a previous sound pressure value to generate a current sound pressure value. Specifically, processor 30 first receives the previous sound pressure value from memory 33 and adds the previous sound pressure value and the transient sound pressure value to generate the current sound pressure value. At this point, processor 30 transfers the current sound pressure value to memory 33 for storage, and the current sound pressure value stored in memory 33 is used as the previous sound pressure value.

[0049] The processor 30 performs steps S13, S14, S151A and S152A for the previous audio signal and the previous detected signal to generate the current sound pressure value, and transfers the corresponding previous audio signal and the previous detected signal to the memory 33 for storage, and the current sound pressure value, which corresponds to the previous audio signal and the previous detected signal, is considered to be the previous sound pressure value.

[0050] Step S153A: Generating the compensation value according to the current sound pressure level. Specifically, the processor 30 transmits the current sound pressure level to the low-frequency cowtail filter 34, and the low-frequency cowtail filter 34 generates a compensation value according to the current sound pressure level. For example, if the current sound pressure level is 5 dB, the compensation value generated by the low-frequency cowtail filter 34 is -5 dB.

[0051] In another embodiment, the processor 30 performs calculations on the first and second sound pressure differences to generate a current sound pressure value and receives an operating signal from an external electronic device to generate a dynamic target sound according to the operating signal. The processor 30 then sets the current sound pressure value according to the dynamic target sound pressure value and generates a compensation value according to the set current sound pressure value.

[0052] Fig. Figure 6B is a flowchart for generating the compensation value in the audio signal processing method according to another implementation of the present invention. As shown in Fig. As shown in Figure 6B, the step of generating a compensation value according to the first sound pressure difference and the second sound pressure difference comprises steps S151B to S155B. Steps S151B and S152B are the same as steps S151A and S152A in Figure 6B. Fig. 6A and are not described again here. The following example illustrates steps S153B to S155B by showing the operation of the in Fig. 1 and Fig. The audio signal processing device shown in section 2 is used for illustration purposes.

[0053] Step S153B: Receiving an external operating signal and generating a dynamic target sound pressure level according to the external operating signal.

[0054] Specifically, the user employs an external electronic device to generate an external operating signal, which is then transmitted to the audio signal processing device. In response to the input of the external operating signal, the processor 30 generates a corresponding dynamic target sound pressure level based on that signal. The external electronic device can generate a variety of different operating signals, and these signals correspond to a variety of different dynamic target sound pressure levels. In other words, the dynamic target sound pressure level changes with changes in the external operating signal.

[0055] Step S154B: Adjusting the current sound pressure level according to the dynamic target sound pressure level. Specifically, processor 30 modifies the current sound pressure level according to the dynamic target sound pressure level. Processor 30 also performs a subtraction operation on the current sound pressure level and the dynamic target sound pressure level. After the subtraction operation, the current sound pressure level is the set current sound pressure level. The set current sound pressure level changes with the dynamic target sound pressure level.

[0056] Step S155B: Generating the compensation value according to the current sound pressure level. Specifically, the processor 30 transmits the set current sound pressure level to the low-frequency cowtail filter 34, and the low-frequency cowtail filter 34 generates a compensation value according to the set current sound pressure level. For example, if the current sound pressure level after adjustment is -3 dB, the compensation value generated by the low-frequency cowtail filter 34 is +3 dB.

[0057] Steps S151B to S155B adjust the current sound pressure level according to the user's preference. Since adjusting the current sound pressure level changes the compensation value, this change affects the sonic effect of the audio signal in the low-frequency portion. For example, steps S151B to S155B either increase or decrease the sonic effect of the low-frequency portion of the audio signal.

[0058] Step S16: Adjusting the audio signal according to the compensation value. In particular, the low-frequency cowtail filter 34 adjusts the sound pressure level of the audio signal according to the compensation value in order to compensate for the frequency response of the audio signal in the low-frequency part.

[0059] When the loudspeaker 10 is playing a piece of music, the piece contains several sections of audio signals. As the loudspeaker 10 plays each section of the audio signal, the processor 30 executes steps S13, S14, S151, and S152 for each section of the audio signal and each section of the detected signal to obtain the corresponding current sound pressure level. The multiple sections of current sound pressure levels, corresponding to the multiple audio signals, are all distinct. The low-frequency shelving filter 34 generates multiple compensation values ​​according to multiple distinct current sound pressure levels, and the processor 30 compensates multiple audio signals according to multiple compensation values.

[0060] For example, a piece of music contains a first audio signal segment, a second audio signal segment, and a third audio signal segment. The first audio signal segment corresponds to the first segment of the detected signal, the second audio signal segment corresponds to the second segment of the detected signal, and the third audio signal segment corresponds to the third segment of the detected signal. When the loudspeaker 10 plays the first audio signal segment, the processor 30 performs steps S13, S14, S151, and S152 on the first audio signal segment and the first segment of the detected signal to generate a first current sound pressure value and transfers the first current sound pressure value to the memory 33 and the low-frequency cowtail filter 34. The low-frequency cowtail filter 34 also generates a first compensation value according to the first current sound pressure value.The low-pass filter 34 uses the first compensation value to adjust the first audio signal section.

[0061] When the loudspeaker 10 plays the second audio signal segment, the processor 30 performs steps S13, S14, and S151 on the second audio signal segment and the second detected signal to generate a second transient sound pressure value. The first current sound pressure value is considered the first previous sound pressure value, and the processor 30 performs step S152 on the second transient sound pressure value and the first previous sound pressure value to generate a second current sound pressure value. The processor then passes this second current sound pressure value to memory 33 and the low-frequency shelving filter 34. The low-frequency shelving filter 34 generates a second compensation value based on the second current sound pressure value. The low-frequency shelving filter 34 uses this second compensation value to compensate for the second audio signal segment.Therefore, if the second transient sound pressure value is zero, the first previous sound pressure value is equal to the second current sound pressure value, and the second compensation value generated by the deep cowtail filter 34 is the same as the first compensation value, thus preventing the deep cowtail filter 34 from setting the compensation value to zero.

[0062] When the loudspeaker 10 reproduces the third audio signal segment, the processor 30 performs steps S13, S14, and S151 on the third audio signal segment and the third detected signal to generate a third transient sound pressure value. The current sound pressure value is considered to be the second previous sound pressure value, and the processor 30 performs step S152 on the third transient sound pressure value and the second previous sound pressure value to generate a third current sound pressure value and transfers the third current sound pressure value to memory 33 for storage. The processor 30 also generates a third compensation value according to the third current sound pressure value, and the low-frequency cowtail filter 34 uses the third compensation value to compensate for the third audio signal segment.Therefore, if the third transient sound pressure value is zero, the second previous sound pressure value is equal to the third current sound pressure value, and the third compensation value generated by the deep cowtail filter 34 is the same as the second compensation value, thus preventing the deep cowtail filter 34 from setting the compensation value to zero.

[0063] In the audio signal processing method of this embodiment, different compensation values ​​are generated according to the correction requirements of several different audio signals in order to compensate for several different audio signals, thereby preventing the occurrence of sound attenuation and amplification.

[0064] Fig. Figure 7 is a flowchart of the audio signal processing method according to another embodiment of the present invention. As in Fig. As shown in Figure 7, the audio signal processing procedure comprises steps S21 to S27. Steps S21 to S24, step S26, and step S27 are the same as those shown in Figure 7. Fig. The 3 steps S11 to S16 shown are not described again here. The following example represents step S25 by describing the operation of the Fig. The audio signal processing device shown in 1 is used for illustration purposes.

[0065] Step S25: Smoothing the first and second sound pressure differences. Specifically, processor 30 performs a smoothing process on the first and second sound pressure differences. It should be noted that the upper cutoff frequency is a high-frequency range based on the reference frequency and has a multitude of first frequency points, and the lower cutoff frequency is a low-frequency range based on the reference frequency and has a multitude of second frequency points. Accordingly, the first sound pressure difference comprises a multitude of first data points, the second sound pressure difference comprises a multitude of second data points, the representative value of the first sound pressure difference is the average of the multitude of first data points, and the representative value of the second sound pressure difference is the average of the multitude of second data points.Therefore, the smoothing process removes abnormal data points from the multitude of first data points and the multitude of second data points.

[0066] In summary, the audio signal processing method and audio signal processing device of the present invention generates a compensation value based on the first sound pressure of the audio signal corresponding to the loudspeaker and the second sound pressure difference of the detected signal corresponding to the microphone, in order to compensate for the audio signal in order to prevent sound attenuation and amplification. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 202422320448.3

[0001]

Claims

[1] Audio signal processing techniques, comprising: - Receiving an audio signal and a detected signal; - Obtaining a frequency range, wherein the frequency range includes an upper cutoff frequency and a lower cutoff frequency; - Calculating a first sound pressure difference between the audio signal filtered at the upper cutoff frequency and the audio signal filtered at the lower cutoff frequency; - Calculating a second sound pressure difference between the detected signal filtered at the upper cutoff frequency and the detected signal filtered at the lower cutoff frequency; - Generating a compensation value according to the first sound pressure difference and the second sound pressure difference; and - Adjusting the audio signal according to the compensation value. [2] Audio signal processing method according to claim 1, wherein preserving the frequency range comprises: - Filtering the audio signal to obtain a first audio signal with respect to the upper cutoff frequency and a second audio signal with respect to the lower cutoff frequency; and - Filtering the detected signal to obtain a first detected signal with respect to the upper cutoff frequency and a second detected signal with respect to the lower cutoff frequency. [3] Audio signal processing method according to claim 1 or claim 2, wherein the calculation of a first sound pressure difference between the audio signal filtered at the upper cutoff frequency and the audio signal filtered at the lower cutoff frequency comprises: according to the first audio signal and the second audio signal, obtaining a first sound pressure value corresponding to the upper cutoff frequency and a second sound pressure value corresponding to the lower cutoff frequency; and Performing a subtraction operation on the first sound pressure value and the second sound pressure value to generate the first sound pressure difference. [4] Audio signal processing method according to one of the preceding claims, in particular claim 2, comprising the calculation of the second sound pressure difference between the detected signal at the upper frequency and the detected signal at the lower frequency: According to the first detected signal and the second detected signal, obtaining a first detected sound pressure value corresponding to the upper cutoff frequency and a second detected sound pressure value corresponding to the lower cutoff frequency; and Performing a subtraction operation on the first detected sound pressure value and the second detected sound pressure value to generate the second sound pressure difference. [5] Audio signal processing method according to any one of claims 1 to 4, wherein generating the compensation value according to the first sound pressure difference and the second sound pressure difference comprises: Performing a subtraction operation on the first sound pressure difference and the second sound pressure difference to generate a transient sound pressure value; Performing an addition operation on the transient sound pressure value and a previous sound pressure value to generate a current sound pressure value; and Generating a compensation value according to the current sound pressure level. [6] Audio signal processing method according to any one of claims 1 to 5, comprising generating the compensation value according to the first sound pressure difference and the second sound pressure difference: Performing a subtraction operation on the first sound pressure difference and the second sound pressure difference to generate a transient sound pressure value; Performing an addition operation on the transient sound pressure value and a previous sound pressure value to generate a current sound pressure value; Receiving an external operating signal and generating a dynamic target sound pressure level according to the external operating signal; adjusting the current sound pressure level according to the dynamic target sound pressure level; and Generating a compensation value according to the set current sound pressure level. [7] Audio signal processing method according to any one of claims 1 to 6, further comprising smoothing the first sound pressure difference and the second sound pressure difference. [8] Audio signal processing device comprising: - a loudspeaker designed to reproduce an audio signal; - a microphone designed to generate a detected signal; and - a processor connected to the speaker and microphone, the processor being configured to perform the following: - Obtaining a frequency range, wherein the frequency range includes an upper cutoff frequency and a lower cutoff frequency; - Calculating a first sound pressure difference between the audio signal filtered at the upper cutoff frequency and the audio signal filtered at the lower cutoff frequency; - Calculating a second sound pressure difference between the detected signal filtered at the upper cutoff frequency and the detected signal filtered at the lower cutoff frequency; - Generating a compensation value according to the first sound pressure difference and the second sound pressure difference; and - Adjusting the audio signal according to the compensation value. [9] Audio signal processing device according to claim 8, wherein the processor comprises a high-pass filter and a low-pass filter, and where the processing of the frequency range involves filtering the audio signal through the high-pass filter and the low-pass filter to obtain a first audio signal with respect to the upper cutoff frequency and a second audio signal with respect to the lower cutoff frequency, and wherein the high-pass filter and the low-pass filter each filter the detected signal according to a reference frequency in order to obtain a first detected signal with respect to the upper cutoff frequency and a second detected signal with respect to the lower cutoff frequency. [10] Audio signal processing device according to claim 8 or claim 9, wherein the calculation of the first sound pressure difference between the audio signal filtered at the upper cutoff frequency and the audio signal filtered at the lower cutoff frequency by the processor comprises the following: The processor receives, according to the first audio signal and the second audio signal, a first sound pressure value corresponding to the upper cutoff frequency and a second sound pressure value corresponding to the lower cutoff frequency; and The processor performs a subtraction operation on the first sound pressure value and the second sound pressure value to generate a first sound pressure difference. [11] Audio signal processing device according to any one of claims 8 to 10, in particular claim 9, wherein the processor calculates a second sound pressure difference between the detected signal filtered at the upper cutoff frequency and the detected signal filtered at the lower cutoff frequency, comprising: Based on the first detected signal and the second detected signal, the processor receives a first detected sound pressure value corresponding to the upper cutoff frequency and a second detected sound pressure value corresponding to the lower cutoff frequency; and The processor performs a subtraction operation on the first detected sound pressure value and the second detected sound pressure value to generate the second sound pressure difference. [12] Audio signal processing device according to any one of claims 8 to 11, wherein the processor comprises: - a storage device designed to store a previous sound pressure level; and - a low-frequency cowtail filter; and wherein generating the compensation value according to the first sound pressure difference and the second sound pressure difference by the processor comprises the following: The processor performs a subtraction operation on the first sound pressure difference and the second sound pressure difference to generate a transient sound pressure value; The processor performs an addition operation on the transient sound pressure value and a previous sound pressure value to generate a current sound pressure value; and The deep cowtail filter generates a compensation value according to the current sound pressure level. [13] Audio signal processing device according to any one of claims 8 to 12, wherein the processor comprises: - a storage device designed to store a previous sound pressure level; and - a low-frequency cowtail filter; and wherein generating the compensation value according to the first sound pressure difference and the second sound pressure difference by the processor comprises the following: The processor performs a subtraction operation on the first sound pressure difference and the second sound pressure difference to generate a transient sound pressure value; The processor performs an addition operation on the transient sound pressure value and the previous sound pressure value to generate a current sound pressure value; The processor receives an external operating signal and generates a dynamic target sound pressure level according to the external operating signal; the processor adjusts the current sound pressure level according to the dynamic target sound pressure level; and The deep cowtail filter generates a compensation value according to the set current sound pressure level. [14] Audio signal processing device according to one of claims 8 to 13, wherein the processor further performs a smoothing process on the first sound pressure difference and the second sound pressure difference.

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