Audio signal processing circuit and audio signal processing method

Abstract

An audio signal processing circuit and an audio signal processing method are disclosed. The audio signal processing circuit includes a filter, a gain control circuit, and a bass boost circuit. The filter is configured to filter an audio signal to generate a filtered signal. The gain control circuit is coupled to the filter and configured to divide the filtered signal into a first segment and a second segment in time domain, measure a first amplitude of the first segment and a second amplitude of the second segment, and generate a gain value based on the first amplitude, wherein the first amplitude is greater than the second amplitude. The bass boost circuit is coupled to the filter and the gain control circuit and configured to adjust the amplitudes of the first segment and the second segment according to the gain value.

Description

Technical Field

[0001] This invention application relates to audio processing, and more particularly to audio processing of low-frequency signals. Background Technology

[0002] The increasingly smaller physical size of speakers in modern electronic devices limits the reproduction of low-frequency signals, leading to consumer dissatisfaction with the sound output quality of audio playback systems, especially low-frequency sounds.

[0003] Increasing the energy of the low-frequency band is an intuitive solution, but too much energy in the low-frequency band may damage the speaker. Alternatively, in order to reduce the energy of the low-frequency band (to avoid damage to the speaker), the overall signal energy may be reduced, which in turn compresses the energy of the mid-to-high frequency band (i.e., makes the mid-to-high frequency sound quieter).

[0004] Therefore, improving users' listening experience of low-frequency signals in a more effective way has become an important topic in this field. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide an audio signal processing circuit and an audio signal processing method to improve the shortcomings of the prior art.

[0006] This invention discloses an audio signal processing circuit, comprising a filter, a gain control circuit, and a bass boost circuit. The filter is used to filter the audio signal to generate a filtered signal. The gain control circuit is coupled to the filter and is used to divide the filtered signal into a first segment and a second segment of substantially equal length in the time domain, measure a first amplitude of the first segment and a second amplitude of the second segment, and generate a gain value based on the first amplitude, wherein the first amplitude is greater than the second amplitude. The bass boost circuit is coupled to the filter and the gain control circuit and is used to adjust the amplitudes of the first segment and the second segment according to the gain value.

[0007] This invention application also discloses an audio signal processing circuit, comprising a first filter, a second filter, a gain control circuit, a bass boost circuit, a third filter, a nonlinear processing circuit, a fourth filter, a delay circuit, and an adder circuit. The first filter filters the audio signal to generate a first filtered signal. The second filter filters the audio signal to generate a second filtered signal. The gain control circuit is coupled to the first filter and is used to divide the first filtered signal into a first segment and a second segment of substantially equal length in the time domain, measure a first amplitude of the first segment and a second amplitude of the second segment, and generate a gain value based on the first amplitude, wherein the first amplitude is greater than the second amplitude. The bass boost circuit is coupled to the second filter and the gain control circuit and is used to adjust the second filtered signal according to the gain value to generate an intermediate signal. The third filter is coupled to the bass boost circuit and is used to filter the intermediate signal to generate a third filtered signal. The nonlinear processing circuit is coupled to the bass boost circuit and is used to process the intermediate signal to generate a harmonic signal. The fourth filter is coupled to the nonlinear processing circuit and is used to filter the harmonic signal to generate a fourth filtered signal. A delay circuit is coupled to the third filter to delay the third filtered signal, thereby generating a delayed signal. An adder circuit is coupled to the delay circuit and the fourth filter to add the fourth filtered signal and the delayed signal to generate an output signal.

[0008] This application further discloses an audio signal processing method, comprising: dividing a signal into multiple segments in the time domain; determining a segment group based on the acoustic characteristics of the signal in the multiple segments, wherein the segment group includes multiple target segments of substantially the same length; measuring the amplitude of the signal in the multiple target segments to determine a characteristic amplitude of the segment group; generating at least one gain value based on the characteristic amplitude; and adjusting the amplitude of the signal in the multiple target segments based on the at least one gain value.

[0009] The features, implementation, and effects of this invention will be described in detail below with reference to the accompanying drawings. Attached Figure Description

[0010] To make the above-mentioned and other objects, features, advantages and embodiments of this invention application clearer and easier to understand, the following description will be made in conjunction with the accompanying drawings.

[0011] Figure 1 This is a functional block diagram of an embodiment of the audio signal processing circuit of this invention.

[0012] Figure 2 This is a flowchart of an embodiment of the audio signal processing method of this invention.

[0013] Figure 3 This is a graph showing the relationship between the amplitude of the filtered signal Sf1 and time.

[0014] Figure 4 A functional block diagram showing one embodiment of the gain control circuit is displayed;

[0015] Figure 5 This is a functional block diagram of another embodiment of the audio signal processing circuit of this invention.

[0016] Figure 6 This is a functional block diagram of another embodiment of the audio signal processing circuit of this invention.

[0017] Figure 7 A functional block diagram of another embodiment of the audio signal processing circuit of this application; and

[0018] Figure 8 This is a functional block diagram of another embodiment of the audio signal processing circuit of this invention.

[0019] Symbol Explanation

[0020] 100, 400, 500, 600, 700: Audio signal processing circuits

[0021] 110, 412, 416, 510, 610: Filters

[0022] 120: Bass Boost Circuit

[0023] 130: Gain control circuit

[0024] Sin: Audio signal

[0025] Sf1, Sf2, Sf3, Sf4, Sf5, Sf6, Sf7, Sf8, Sf9: Filtered signals

[0026] G: Gain value

[0027] Sout: Output signal

[0028] t1, t2, t3, t4, t5, t6, tk, tk+1: Time points

[0029] A1, A2, A3, A4, A5, Ak: Sections

[0030] AG: Segment Group

[0031] Bth: Threshold Value

[0032] 310, 320: Curves

[0033] 132: Calculation Circuit

[0034] 134: Memory

[0035] 410: Virtual bass circuit

[0036] 420, 520: Delay circuits

[0037] 430, 620: Adder circuit

[0038] 414: Nonlinear processing circuit

[0039] SH: Harmonic signal

[0040] Sm1, Sm2: Intermediate signals

[0041] Sd1, Sd2, Sd3, Sd4: Delayed signals

[0042] S210, S220, S225, S230, S240, S250: Steps Detailed Implementation

[0043] The technical terms used in the following description are conventional terms in this technical field. If this specification provides explanations or definitions for certain terms, the explanations or definitions in this specification shall prevail.

[0044] The technical terms used in the following description are based on the customary terms in this technical field. If this specification provides explanations or definitions for certain terms, the explanations or definitions in this specification shall prevail.

[0045] The disclosure of this invention application includes an audio signal processing circuit and an audio signal processing method. Since some components of the audio signal processing circuit of this invention application may be known individually, details of known components will be omitted in the following description without affecting the full disclosure and implementability of the device invention. Furthermore, some or all of the processes of the audio signal processing method of this invention application can be in software and / or hardware form, and can be executed by the audio signal processing circuit of this invention application or its equivalent device. Without affecting the full disclosure and implementability of the method invention, the following description of the method invention will focus on the steps rather than the hardware.

[0046] Figure 1This is a functional block diagram of an embodiment of the audio signal processing circuit of this invention. The audio signal processing circuit 100 includes a filter 110, a bass boost circuit 120, and a gain control circuit 130. The filter 110 is used to filter the audio signal Sin to generate a filtered signal Sf1. The filtered signal Sf1 is the low-frequency component of the audio signal Sin; that is, the filter 110 can be a band-pass filter or a low-pass filter. The gain control circuit 130 generates a gain value G based on multiple segments of the filtered signal Sf1 in the time domain, and the bass boost circuit 120 adjusts the filtered signal Sf1 according to the gain value G to generate an output signal Sout.

[0047] Please see Figure 2 , Figure 2 This is a flowchart of an embodiment of the audio signal processing method of this invention. Figure 2 The process is executed by the bass boost circuit 120 and the gain control circuit 130, and includes the following steps.

[0048] Step S210: The gain control circuit 130 divides the filtered signal Sf1 (i.e., the low-frequency component of the audio signal Sin) into multiple segments of substantially equal length in the time domain. (See also...) Figure 3 , Figure 3 This is a graph showing the relationship between the amplitude of the filtered signal Sf1 and time. As shown in the figure, the filtered signal Sf1 is divided into multiple segments in time by the gain control circuit 130 (including segment A1 between time points t1 and t2, segment A2 between time points t2 and t3, ..., segment Ak between time points tk and tk+1, ..., where k is a positive integer). The lengths of these multiple segments are substantially the same (i.e., t2-t1 = t3-t2 = t4-t3 = ... = tk+1-tk).

[0049] Step S220: The gain control circuit 130 determines a segment group, which includes multiple target segments. Step S220 includes sub-step S225: The gain control circuit 130 determines the target segments in the segment group by analyzing and / or comparing acoustic features (e.g., frequency components, timbre, time envelope, etc.), where the multiple target segments have the same or similar frequency distribution or frequency components. In some embodiments, the gain control circuit 130 analyzes the frequency components of the filtered signal Sf1 in each segment and considers segments containing one or more target frequency bands as target segments. For example, assuming the target frequency bands are 30–50 Hz and 80–95 Hz, and when segments A1 and A2 both have signal components in the 30–50 Hz and 80–95 Hz frequency bands, the gain control circuit 130 classifies segments A1 and A2 into the same segment group (i.e., considers segments A1 and A2 as target segments).

[0050] Because all target segments in a segment group have the same or similar frequency components, the segment group may correspond to the same timbre signal. Even if the spectral distribution of the same pitch is similar in musical expression, the proportions of each frequency component contained when the electric guitar, trumpet, and timpani produce the same pitch are different, which allows the human senses to distinguish the timbre of different sound sources.

[0051] In the following explanation, the example is taken as segment group AG containing segments A2, A3, A4 and A5 (that is, segments A2 to A5 are the target segments).

[0052] Step S230: The gain control circuit 130 measures or detects the amplitude of each target segment within the segment group to determine the characteristic amplitude of the segment group. Continuing the example above, the gain control circuit 130 measures the amplitudes of segments A2 to A5, obtaining amplitudes B2 to B5 corresponding to segments A2 to A5 respectively, and takes the largest amplitude among B2 to B5 as the characteristic amplitude of the segment group AG. It should be understood that taking the largest amplitude in the segment group can be a dynamic concept to implement real-time gain adjustment. For example, in other embodiments, if the amplitude relationship corresponding to segments A2 to A5 is amplitude B3 > amplitude B2 > amplitude B4 > amplitude B5. As time progresses, the maximum amplitude at time point t3 (after segment A2) is amplitude B2; at time point t4 (after segment A3), the maximum recorded amplitude is amplitude B3; when time progresses to time points t5 (after segment A4) and t6 (after segment A5), the maximum recorded amplitude of the segment group is still amplitude B3 (that is, based on the progress of time, after at least two target segments have elapsed, the "maximum recorded amplitude" can be obtained based on the target segments that have been experienced, and the amplitude B3 in the aforementioned embodiment belongs to the "local maximum amplitude" in the segment group).

[0053] Step S240: The gain control circuit 130 generates at least one gain value G based on the characteristic amplitude. In some embodiments, the gain control circuit 130 uses the ratio of the characteristic amplitude to the amplitude of the target segment as the gain value G; for example, continuing the previous example, assuming that the amplitude B2 of segment A2 among segments A2 to A5 is the largest (i.e., the characteristic amplitude is B2), then the gain values ​​G corresponding to segments A3, A4, and A5 are B2 / B3, B2 / B4, and B2 / B5, respectively. In other embodiments, the gain control circuit 130 uses a lookup table (stored in memory) to determine the gain value G based on the characteristic amplitude, and the gain value G can be used for all target segments in the segment group (i.e., the gain value G is determined based on the "maximum amplitude of the region").

[0054] Step S250: The bass boost circuit 120 adjusts the amplitudes B2 to B5 of the filtered signal Sf1 in the plurality of target segments A2 to A5 according to the at least one gain value G. In some embodiments, the bass boost circuit 120 multiplies the amplitudes B2 to B5 of segments A2 to A5 by the gain value G to boost the amplitude of segments A2 to A5. In other words, after processing by the bass boost circuit 120, the filtered signal Sf1 receives a relevant amplitude or energy boost within the time corresponding to the segment group AG (i.e., between time points t2 and t6). As mentioned above, the method by which the gain control circuit 130 generates the gain value G based on the characteristic amplitude is not limited to this. If a real-time gain adjustment method is adopted, the gain control circuit 130 may generate the gain value G based on "recording the maximum amplitude" rather than "the maximum amplitude of the region" as time progresses. Therefore, the gain value G may also change frequently. Furthermore, the method of gain adjustment is not limited to this; in addition to the overall adjustment of the gain value G, the bass boost circuit 120 may also adjust the amplitude of each segment individually. In some embodiments, if the bass boost circuit 120 makes additional gain adjustments to the characteristic amplitude itself (e.g., with a gain value α), the filtered signal Sf1 can receive a higher (but not limited) amplitude or energy boost within the time of the segment group AG. For example, if a gain of B2*α is applied to the characteristic amplitude B2, the post-gain amplitudes corresponding to segments A3, A4, and A5 are B2*α / B3, B2*α / B4, and B2*α / B5, respectively.

[0055] In summary, the audio signal processing circuit 100 can appropriately boost the low-frequency components of the audio signal Sin (i.e., the filtered signal Sf1), allowing the low-frequency components with lower energy to exceed the user's hearing threshold Bth (i.e., making it easier for the user to perceive low-frequency sounds), while still maintaining the relative magnitudes within the same tone. Figure 3 As shown, the amplitude of the filtered signal Sf1 (curve 310) before processing by the bass boost circuit 120 is less than the threshold value Bth in segments A4 and A5 (i.e., the user cannot perceive low-frequency sound after time point t4). However, the amplitude of the filtered signal Sf1 (curve 320) after processing by the bass boost circuit 120 is still greater than the threshold value Bth between time points t4 and t5. In other words, after the audio signal Sin is processed, its dynamic range decreases (i.e., decays) more slowly. Therefore, the user can perceive a stronger and longer-lasting low-frequency sound (i.e., a more obvious low-frequency effect).

[0056] In some embodiments, the sub-step S225 described above can assist in determining the similarity of spectral or frequency components by training artificial intelligence (AI, such as a neural network).

[0057] In some embodiments, for segments that do not belong to any segment group (i.e., non-target segments), the gain control circuit 130 determines its gain value G to be 1 (i.e., the bass boost circuit 120 does not adjust the amplitude of the segment), or determines the gain value G by looking up a table according to the values ​​of each segment.

[0058] In some embodiments, the bass boost circuit 120 is a signal amplifier used to multiply the filtered signal Sf1 by the gain value G to generate the output signal Sout.

[0059] In some embodiments, such as Figure 4 As shown, the gain control circuit 130 includes a computing circuit 132 and a memory 134. The computing circuit 132 can be a circuit or electronic component with program execution capability, such as a central processing unit, microprocessor, microcontroller, microprocessor unit, digital signal processor (DSP), or equivalent circuit. The computing circuit 132 executes program code or program instructions stored in the memory 134. Figure 2 The steps are as follows. In other embodiments, those skilled in the art can design the gain control circuit 130 based on the above disclosure. That is, the gain control circuit 130 can be an application-specific integrated circuit (ASIC) or implemented by circuits or hardware such as a programmable logic device (PLD).

[0060] The audio signal processing circuit 100 can be combined with the virtual bass circuit. Figure 5 This is a functional block diagram of another embodiment of the audio signal processing circuit of this invention. The audio signal processing circuit 400 includes a filter 110, a bass boosting circuit 120, a gain control circuit 130, a virtual bass circuit 410, a delay circuit 420, and an adder circuit 430. The virtual bass circuit 410 includes a filter 412, a nonlinear processing circuit 414, and a filter 416.

[0061] Filter 412 is used to filter the audio signal Sin to generate a filtered signal Sf2. Filter 412 is a low-pass filter or a band-pass filter, and the frequency band of the filtered signal Sf2 is a frequency band that the speaker cannot produce at all. Nonlinear processing circuit 414 is used to process the filtered signal Sf2 to generate a harmonic signal SH. For example, the harmonic signal SH may contain harmonics at 200Hz, 300Hz, 400Hz, and 500Hz. Filter 416 is used to filter the harmonic signal SH to generate a filtered signal Sf3. Filter 416 can be a band-pass filter used to filter out unwanted harmonics in the harmonic signal SH; for example, filtering out harmonics above 500Hz leaves only the 200Hz, 300Hz, and 400Hz harmonics in the harmonic signal SH. Delay circuit 420 is used to delay the intermediate signal Sm1 generated by the bass boost circuit 120 and generate a delay signal Sd1 that is time-aligned with the filtered signal Sf3. The adder circuit 430 adds the filtered signal Sf3 and the delayed signal Sd1 to generate the output signal Sout.

[0062] The virtual bass circuit 410 is based on psychoacoustics, utilizing the harmonics of multiple low-frequency signals to generate a virtual pitch, thereby enhancing the user's perception of low-frequency sounds. The nonlinear processing circuit 414 is well-known to those skilled in the art; details can be found in TW patent document I462601, "Audio signal device and method."

[0063] Figure 6 This is a functional block diagram of another embodiment of the audio signal processing circuit of this invention. The audio signal processing circuit 500 includes a filter 110, a bass boost circuit 120, a gain control circuit 130, a virtual bass circuit 410, a delay circuit 420, an adder circuit 430, a filter 510, and a delay circuit 520. The filter 510 is used to filter the audio signal Sin to generate a filtered signal Sf4. The filter 510 can be a high-pass filter used to filter out low-frequency bands that the speaker cannot produce sound (i.e., the filtered signal Sf4 is the mid-to-high frequency component of the audio signal Sin). The delay circuit 520 is used to delay the filtered signal Sf4 to generate a delayed signal Sd2 aligned with the filtered signal Sf3. The adder circuit 430 adds the delayed signal Sd2, the filtered signal Sf3, and the delayed signal Sd1 to generate an output signal Sout.

[0064] Figure 7This is a functional block diagram of another embodiment of the audio signal processing circuit of this invention. The audio signal processing circuit 600 includes a filter 110, a bass boost circuit 120, a gain control circuit 130, a filter 412, a nonlinear processing circuit 414, a filter 416, a delay circuit 420, a filter 610, and an adder circuit 620. Filter 110 is used to filter the audio signal Sin to generate a filtered signal Sf5. The filtered signal Sf5 is the low-frequency component of the audio signal Sin. Filter 412 is used to filter the audio signal Sin to generate a filtered signal Sf6. Gain control circuit 130 generates a gain value G based on multiple segments in the time domain of the filtered signal Sf5, and bass boost circuit 120 adjusts the filtered signal Sf6 based on the gain value G to generate an intermediate signal Sm2. Nonlinear processing circuit 414 is used to process the intermediate signal Sm2 to generate a harmonic signal SH. Filter 416 is used to filter the harmonic signal SH to generate a filtered signal Sf7. Filter 610 is used to filter the intermediate signal Sm2 to adjust the frequency range for enhancing low-frequency signals (the range of harmonic generation and enhancement may differ; in some embodiments, filter 610 is an optional component) to generate a filtered signal Sf8. Delay circuit 420 is used to delay the filtered signal Sf8 and generate a delayed signal Sd3 that is time-aligned with the filtered signal Sf7. Adder circuit 620 adds the filtered signal Sf7 and the delayed signal Sd3 to generate the output signal Sout.

[0065] Figure 8 This is a functional block diagram of another embodiment of the audio signal processing circuit of this invention. The audio signal processing circuit 700 includes a filter 110, a bass boost circuit 120, a gain control circuit 130, a filter 412, a nonlinear processing circuit 414, a filter 416, a delay circuit 420, a filter 510, a delay circuit 520, a filter 610, and an adder circuit 620. Filter 510 is used to filter the audio signal Sin to generate a filtered signal Sf9 (the filtered signal Sf9 is the mid-to-high frequency component of the audio signal Sin). Delay circuit 520 is used to delay the filtered signal Sf9 to generate a delayed signal Sd4 aligned with the filtered signal Sf7. Adder circuit 620 adds the delayed signal Sd4, the filtered signal Sf7, and the delayed signal Sd3 to generate an output signal Sout.

[0066] The audio signal processing circuit and method disclosed in this invention can adaptively adjust the amplitude of the low-frequency components of an audio signal. Compared to conventional technologies, this invention improves the user's listening experience for low-frequency signals.

[0067] Since those skilled in the art can understand the implementation details and variations of the method invention of this application through the disclosure of the device invention, to avoid redundancy, repeated descriptions are omitted here without affecting the disclosure requirements and implementability of the method invention. Please note that the shapes, sizes, and proportions of the components in the illustrations disclosed above are merely illustrative and are intended to help those skilled in the art understand the invention, and are not intended to limit the invention. Furthermore, in some embodiments, the steps mentioned in the flowcharts disclosed above may be adjusted in order according to actual operation, and may even be performed simultaneously or partially simultaneously.

[0068] Although the contents of this application have been disclosed above through specific embodiments, these embodiments are not intended to limit the contents of this application. Those skilled in the art can modify or adjust the technical solutions of this application based on the explicit or implicit contents of this application without departing from the concept and scope of this application. All such changes may fall within the scope of patent protection sought by this application. In other words, the scope of protection of this application shall be determined by the scope defined in the claims.

Claims

1. An audio signal processing circuit, characterized by, The audio signal processing circuit includes: a filter for filtering an audio signal to generate a filtered signal; a gain control circuit coupled to the filter for dividing the filtered signal into a plurality of segments of substantially equal length in time domain, determining a segment group including a plurality of target segments having the same or similar frequency distribution, measuring an amplitude of each target segment in the segment group, and taking a maximum amplitude among the amplitudes of the plurality of target segments as a characteristic amplitude of the segment group, and generating a gain value for each target segment in the plurality of target segments based on the characteristic amplitude; and a bass boost circuit coupled to the filter and the gain control circuit for adjusting an amplitude of each target segment in the plurality of target segments according to the gain value of the target segment.

2. The audio signal processing circuit of claim 1, wherein, The gain control circuit performs spectral analysis on the plurality of segments to determine the segment group.

3. The audio signal processing circuit of claim 1, wherein, The filter is a first filter, the filtered signal is a first filtered signal, and the bass boost circuit generates an intermediate signal, the audio signal processing circuit further includes: a second filter for filtering the audio signal to generate a second filtered signal; a nonlinear processing circuit coupled to the second filter for processing the second filtered signal to generate a harmonic signal; a third filter coupled to the nonlinear processing circuit for filtering the harmonic signal to generate a third filtered signal; a delay circuit coupled to the bass boost circuit for delaying the intermediate signal to generate a delayed signal; and an adding circuit coupled to the third filter and the delay circuit for adding the third filtered signal and the delayed signal to generate an output signal. The filter is a first filter, the filtered signal is a first filtered signal, and the bass boost circuit generates an intermediate signal, the audio signal processing circuit further includes:

4. The audio signal processing circuit of claim 1, wherein, a second filter for filtering the audio signal to generate a second filtered signal; a nonlinear processing circuit coupled to the second filter for processing the second filtered signal to generate a harmonic signal; a third filter coupled to the nonlinear processing circuit for filtering the harmonic signal to generate a third filtered signal; a first delay circuit coupled to the bass boost circuit for delaying the intermediate signal to generate a first delayed signal; a fourth filter for filtering the audio signal to generate a fourth filtered signal; a second delay circuit coupled to the fourth filter for delaying the fourth filtered signal to generate a second delayed signal; and an adding circuit coupled to the third filter, the first delay circuit, and the second delay circuit for adding the third filtered signal, the first delayed signal, and the second delayed signal to generate an output signal. The audio signal processing circuit includes: a first filter for filtering an audio signal to generate a first filtered signal; 5. An audio signal processing circuit, characterized by a second filter for filtering the audio signal to generate a second filtered signal; ​ ​ a gain control circuit coupled to the first filter, for dividing the first filtered signal into a plurality of segments of substantially equal length in time domain, determining a segment group comprising a plurality of target segments having the same or similar frequency distribution, measuring the amplitude of each target segment in the segment group, and taking the maximum amplitude among the amplitudes of the plurality of target segments as a characteristic amplitude of the segment group, and generating a gain value for each target segment in the plurality of target segments based on the characteristic amplitude; a bass boost circuit coupled to the second filter and the gain control circuit, for adjusting the second filtered signal according to the gain value to generate an intermediate signal; a third filter coupled to the bass boost circuit, for filtering the intermediate signal to generate a third filtered signal; a nonlinear processing circuit coupled to the bass boost circuit, for processing the intermediate signal to generate a harmonic signal; a fourth filter coupled to the nonlinear processing circuit, for filtering the harmonic signal to generate a fourth filtered signal; a delay circuit coupled to the third filter, for delaying the third filtered signal to generate a delayed signal; and an adding circuit coupled to the delay circuit and the fourth filter, for adding the fourth filtered signal and the delayed signal to generate an output signal. The gain control circuit is configured to perform a spectral analysis on the plurality of segments to determine the segment group.

6. The audio signal processing circuit of claim 5, wherein, In an embodiment, the delay circuit is a first delay circuit, and the delayed signal is a first delayed signal, and the audio signal processing circuit further comprises:

7. The audio signal processing circuit of claim 5, wherein, a fifth filter, for filtering the audio signal to generate a fifth filtered signal; and a second delay circuit coupled to the fifth filter, for delaying the fifth filtered signal to generate a second delayed signal; and the adding circuit is further coupled to the second delay circuit, and the output signal further comprises the second delayed signal. The audio signal processing method comprises: dividing a signal into a plurality of segments in time domain; 8. An audio signal processing method, characterized by, determining a segment group based on the acoustic characteristics of the signal in the plurality of segments, wherein the segment group comprises a plurality of target segments of substantially equal length, and the plurality of target segments have the same or similar frequency components; measuring the amplitudes of the signal in the plurality of target segments, and taking the maximum amplitude among the amplitudes of the plurality of target segments as a characteristic amplitude of the segment group; generating a gain value for each target segment in the plurality of target segments based on the characteristic amplitude; and adjusting the amplitude of the corresponding target segment of the signal according to the gain value of each target segment in the plurality of target segments. The step of determining the segment group based on the frequency components of the signal in the plurality of segments is configured to perform a spectral analysis on the plurality of segments. ​ ​ 9. The audio signal processing method of claim 8, wherein, ​

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