Voice output control device

Abstract

To provide a voice output control device capable of outputting sound of stable sound quality from a speaker even when a minimum resonance frequency fs of the speaker changes due to deterioration over time.SOLUTION: A voice output control device 10 includes a minimum resonance frequency measuring unit 111, a state determining unit 112, an output control value setting unit 113, and an equalizer 13. The minimum resonance frequency measuring unit 111 measures a minimum resonance frequency fs when a speaker 30 outputs sound on the basis of an input sound signal. The state determining unit 112 determines the degree of deterioration of the speaker 30 on the basis of the minimum resonance frequency fs. The output control value setting unit 113 sets a control value for each frequency band of the sound signal input to the speaker 30 on the basis of the degree of deterioration of the speaker 30. The equalizer 13 controls the output volume for each frequency band of the sound output by the speaker 30 on the basis of the control value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an audio output control device. [Background technology]

[0002] Patent Document 1 describes a speaker driving device equipped with a correction filter circuit whose frequency characteristics have a valley peak waveform that flattens out the peak waveform of low-frequency resonance that occurs at the lowest resonance frequency fs of a speaker housed in a small cabinet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-28419 A Summary of the Invention [Problem to be solved by the invention]

[0004] The speaker driver described in Patent Document 1 aims to achieve high-quality bass reproduction in a speaker housed in a small cabinet by flattening the low-frequency resonance peak that occurs at the lowest resonance frequency fs. However, the lowest resonance frequency fs of a speaker changes with the deterioration of speaker components, such as the damper, over time. As a result, the sound quality of the speaker changes with the deterioration over time.

[0005] An object of the present invention is to provide an audio output control device that can output audio with stable sound quality from a speaker even if the minimum resonance frequency fs of the speaker changes due to deterioration over time. [Means for solving the problem]

[0006] The present invention provides an audio output control device comprising: a minimum resonance frequency measuring unit that measures the lowest resonance frequency when a speaker is outputting audio based on an input audio signal; a state determination unit that determines the degree of deterioration of the speaker based on the minimum resonance frequency; an output control value setting unit that sets a control value for each frequency band of the audio signal input to the speaker based on the degree of deterioration of the speaker; and an equalizer that controls the output volume for each frequency band of the audio output by the speaker based on the control value. Effect of the Invention

[0007] According to the audio output control device of the present invention, even if the minimum resonance frequency fs of the speaker changes due to deterioration over time, audio with stable sound quality can be output from the speaker. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a sound output control device according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing a circuit for measuring the lowest resonance frequency fs in an audio output control device according to an embodiment. [Diagram 3] FIG. 3 is a graph showing the impedance curve of a speaker. [Figure 4] FIG. 4 is a graph showing a reference value of the minimum resonance frequency and the minimum resonance frequency after deterioration over time. [Diagram 5] FIG. 5 is a diagram showing a first example of the speaker adjustment information. [Figure 6] FIG. 6 is a diagram showing a second example of the speaker configuration information. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an audio output control device according to an embodiment will be described with reference to the accompanying drawings. In the description of the drawings, the same parts are given the same reference numerals and the description will be omitted.

[0010] With reference to FIG. 1, an example of the configuration of an audio output control device according to an embodiment will be described. A DSP (Digital Signal Processor) amplifier 10 shown in FIG. 1 performs various processes, which will be described later, on an input digital audio signal. The DSP amplifier 10 constitutes an audio output control device according to an embodiment. The DSP amplifier 10 includes a CPU (Central Processing Unit) 11, a memory (not shown), a storage unit 12, and an equalizer 13, and these components are electrically connected via a bus (not shown). A speaker 30 is connected to the DSP amplifier 10 shown in FIG. 1, and a digital audio signal processed by the DSP amplifier 10 is converted into an analog signal by a D / A converter (not shown) and input to the speaker 30.

[0011] A digital audio signal is input to the DSP amplifier 10 shown in Fig. 1. The digital audio signal is a time domain signal, and the DSP 10 performs various processes to the time domain signal, which will be described later. The DSP 10 may convert the digital audio signal into a frequency domain signal by performing a Discrete Fourier Transform (DFT) and then perform various processes to be described later. Typically, a Fast Fourier Transform (FFT) is used as the DFT. In this case, a Discrete Fourier Transformer is provided in front of an equalizer 13, which will be described later, in the DSP 10.

[0012] A time domain digital audio signal or a frequency domain digital audio signal subjected to a discrete Fourier transform is input to the equalizer 13. FIG.

[0013] The equalizer 13 amplifies or attenuates the sound pressure of each frequency band of the digital audio signal based on a control value of the digital audio signal set by an output control value setting unit described later, thereby correcting the digital audio signal. The equalizer 13 outputs the corrected digital audio signal to the speaker 30 via a D / A converter.

[0014] An analog audio signal is input to the speaker 30. The speaker 30 has a magnet, a voice coil wound around a voice coil bobbin, a diaphragm, and a damper. An end of the voice coil bobbin is connected to the center of the diaphragm, and the damper is connected to the voice coil bobbin and a frame to position the voice coil bobbin. By passing a predetermined amount of current through the voice coil based on the audio signal input to the speaker 30, the air inside the speaker 30 is compressed or expanded to become a kind of air spring, and the vibration of this air spring resonates the diaphragm at a specific frequency, outputting sound corresponding to the audio signal.

[0015] The storage unit 12 stores various information necessary to realize the functions of the audio output control device. The storage unit 12 is an arbitrary storage medium such as a semiconductor memory.

[0016] The CPU 11 executes processes to realize the functions of the audio output control device. The CPU 11 loads various programs stored in the storage unit 12 or the like into a memory, and executes various commands included in the programs. The memory is a storage medium such as a RAM (Random Access Memory).

[0017] The CPU 11 includes, as examples of functional configurations, a minimum resonance frequency measuring unit 111, a state determining unit 112, and an output control value setting unit 113.

[0018] The minimum resonance frequency measuring unit 111 measures the minimum resonance frequency when the speaker 30 is outputting sound based on an input audio signal. The minimum resonance frequency measuring unit 111 measures the current minimum resonance frequency fs of the speaker 30. The minimum resonance frequency measuring unit 111 measures the minimum resonance frequency by using, for example, a circuit as shown in FIG.

[0019] In the circuit of Fig. 2, the DSP amplifier 10 is normally connected to the speaker 30 by setting the switch SW to the terminal Ta side. As shown in Fig. 2, a micro resistor 40 is provided in a positive signal line connecting the DSP amplifier 10 and one end of the speaker 30. The resistance value of the micro resistor 40 is R. In addition, an fs monitor circuit 20, which is a voltage measurement circuit, is connected to both ends of the micro resistor 40.

[0020] The minimum resonant frequency measuring unit 111 switches the switch SW from terminal Ta to terminal Tb at a predetermined timing, and outputs a frequency sweep signal whose frequency gradually changes while the switch SW is switched from terminal Ta to terminal Tb. A sine wave signal whose frequency changes over time is used as the frequency sweep signal.

[0021] With the switch SW switched from terminal Ta to terminal Tb, the fs monitor circuit 20 detects the voltage value at the output end of the micro resistor 40. The fs monitor circuit 20 outputs the detected voltage value to the minimum resonant frequency measuring unit 111.

[0022] The minimum resonant frequency measuring unit 111 calculates the impedance Zsp of the speaker 30 at each frequency by applying the voltage value Vr of the microresistor 40 when a frequency sweep signal is output, the voltage value Vsp between the input terminals of the speaker 30 measured by a measurement circuit not shown, and the resistance value R of the microresistor 40 to the following equation.

[0023] Zsp = R Vsp / Vr

[0024] The minimum resonance frequency measuring unit 111 can calculate the impedance characteristics of the speaker 30 based on the impedance Zsp of the speaker 30 at each frequency. The minimum resonance frequency measuring unit 111 can find the minimum resonance frequency fs by finding the peak of the mountain of the calculated impedance characteristics.

[0025] The impedance characteristics of a typical speaker will be explained with reference to Figure 3. The horizontal axis of Figure 3 indicates frequency, and the vertical axis indicates speaker impedance. As shown in Figure 3, the impedance of a typical speaker is highest at the minimum resonance frequency fs, which is the lowest frequency that the speaker can reproduce, and as the frequency increases, it drops once, and then gradually increases toward the higher frequency ranges.

[0026] The timing at which the switch SW is switched from the terminal Ta to the terminal Tb to output the frequency sweep signal, i.e., the timing at which the lowest resonant frequency fs is measured, is not particularly limited. For example, when the speaker 30 is outputting music, the lowest resonant frequency measurement unit 111 may switch the switch SW from the terminal Ta to the terminal Tb to output the frequency sweep signal when it detects that the music has stopped between songs.

[0027] Furthermore, when it is detected that the user has instructed to measure the lowest resonance frequency by, for example, operating a button, the minimum resonance frequency measuring unit 111 may switch the switch SW from terminal Ta to terminal Tb to output a frequency sweep signal.

[0028] Furthermore, the minimum resonance frequency measurement unit 111 can calculate the impedance of the speaker 30 for a predetermined time without using a frequency sweep signal while the speaker 30 is outputting music, and calculate the minimum resonance frequency fs by frequency analyzing the calculated impedance for the predetermined time. However, for more accurate measurement, it is preferable to use a frequency sweep signal as described above. Also, it is preferable to measure the minimum resonance frequency fs after about 10 minutes have passed since the speaker 30 started outputting sound and the damper movement has stabilized to a certain extent.

[0029] It is known that the minimum resonance frequency fs of a typical speaker decreases with the deterioration of the damper, which is one of the speaker's components, over time. Figure 4 shows an example of the change over time in the sound pressure level and impedance characteristics of a speaker. In Figure 4, the solid lines F1 and f1 show the sound pressure level and impedance characteristics of a speaker before a reliability test in which a speaker is subjected to rated input for 100 continuous hours. The dashed lines F2 and f2 show the sound pressure level and impedance characteristics of the speaker after the reliability test.

[0030] As shown in Figure 4, after 100 hours of reliability testing, the impedance characteristic changes from f1 to f2, and the minimum resonance frequency fs drops. In other words, Figure 4 shows that the minimum resonance frequency fs drops with time, and the sound quality of the speaker changes with time degradation. Therefore, by measuring the current minimum resonance frequency fs of the speaker, the current condition of the speaker can be determined.

[0031] The state determination unit 112 determines the degree of deterioration of the speaker 30 based on the current lowest resonance frequency fs of the speaker 30 measured by the lowest resonance frequency measurement unit 111. The state determination unit 112 determines the degree of deterioration of the speaker 30 based on speaker adjustment information previously stored in the storage unit 12. The speaker adjustment information will be described later.

[0032] Furthermore, the output control value setting unit 113 sets a control value for each frequency band of the digital audio signal input to the speaker 30, based on the degree of deterioration of the speaker 30. The output control value setting unit 113 sets a control value for each frequency band of the audio signal input to the speaker 30, based on the degree of deterioration of the speaker 30 and the speaker adjustment information stored in advance in the storage unit 12.

[0033] The speaker adjustment information in one embodiment will be described with reference to Fig. 5. First, the speaker adjustment information includes a criterion for determining the degree of deterioration of the speaker 30, which is set in advance according to the minimum resonance frequency fs measured by the minimum resonance frequency measurement unit 111.

[0034] In the example shown in FIG. 5, the state determination unit 112 determines, based on the speaker adjustment information, that the degree of deterioration of the speaker 30 is “low” if the measured current lowest resonant frequency fs of the speaker 30 is 100 Hz or higher, “medium” if the measured current lowest resonant frequency fs is greater than 90 Hz and less than 100 Hz, and “high” if the measured current lowest resonant frequency fs is 90 Hz or lower.

[0035] A degree of deterioration of the speaker 30 being "low" indicates that the current minimum resonance frequency fs of the speaker 30 has not decreased significantly from the minimum resonance frequency fs of the speaker 30 at the time of shipment as a product specification of the speaker 30, and that the deterioration of the speaker 30 is relatively small.

[0036] The degree of deterioration of the speaker 30 being "medium" means that the current minimum resonance frequency fs of the speaker 30 has decreased to a moderate degree from the minimum resonance frequency fs of the speaker 30 at the time of shipment as a product specification of the speaker 30, and that the deterioration of the speaker 30 has progressed to a certain extent.

[0037] The degree of deterioration of the speaker 30 being "high" indicates that the current lowest resonance frequency fs of the speaker 30 has significantly decreased from the lowest resonance frequency fs at the time of shipment as the product specifications of the speaker 30, and the deterioration of the speaker 30 has progressed. The degree of deterioration of the speaker 30 being "high" indicates, for example, a case in which the current lowest resonance frequency fs of the speaker 30 has a characteristic of f2 in FIG. 4. FIG. 4 shows that when the current lowest resonance frequency fs of the speaker 30 changes from the characteristic f1 at the time of shipment as the product specifications of the speaker 30 to the characteristic f2, the specification of the sound pressure level of the speaker 30 also changes from the characteristic F1 at the time of shipment to the characteristic F2. The output control value setting unit 113 sets, as the output control value, a control value for correcting the characteristic of the sound pressure level of the speaker 30, which is the characteristic F2 in FIG. 4, to the characteristic F1, which is the characteristic of the original sound pressure level of the speaker 30.

[0038] The speaker adjustment information further includes an amplification frequency band (first frequency band) for amplifying the digital audio signal input to the speaker 30, an amplification degree for amplifying the digital audio signal in the amplification frequency band, and an attenuation frequency band (second frequency band) for attenuating the digital audio signal, which are preset according to the degree of deterioration of the speaker 30. In this way, the speaker adjustment information is adjustment information for correcting sound quality, which is preset according to deterioration over time, the degree of progress of changes in sound quality, the level at which sound quality changes, and the like, which differ for each product type of the speaker 30.

[0039] In the example shown in FIG. 5, the output control value setting unit 113 sets the control value of the digital audio signal based on the speaker adjustment information so that when the degree of deterioration of the speaker 30 is “low”, the audio signal input to the speaker 30 is not amplified, and the audio signal is attenuated in the frequency band below the current lowest resonant frequency fs of the speaker 30.

[0040] In addition, when the degree of deterioration of the speaker 30 is "medium", the output control value setting unit 113 sets the control value of the digital audio signal so as to amplify the digital signal by 5 dB in the frequency band from the current lowest resonance frequency fs of the speaker 30 to a frequency obtained by adding 20 Hz to the current lowest resonance frequency fs, and to attenuate the audio signal in the frequency band below the current lowest resonance frequency fs of the speaker 30.

[0041] Furthermore, when the degree of deterioration of the speaker 30 is "high", the output control value setting unit 113 sets the control value of the digital audio signal so as to amplify the digital audio signal by 10 dB in the frequency band from the current lowest resonance frequency fs of the speaker 30 to a frequency obtained by adding 20 Hz to the current lowest resonance frequency fs, and to attenuate the audio signal in the frequency band below the current lowest resonance frequency fs of the speaker 30.

[0042] Note that the various pieces of information included in the speaker adjustment information may be set in advance based on the minimum resonance frequency fs as a product specification of the speaker 30. That is, in this embodiment, the speaker adjustment information needs to be stored for each product specification of the speaker 30.

[0043] The output control value setting unit 113 outputs the control value of the digital audio signal to the equalizer 13. The equalizer 13 amplifies or attenuates the sound pressure of each frequency band of the digital audio signal to correct the digital audio signal based on the control value set by the output control value setting unit 113. The equalizer 13 outputs the corrected digital audio signal to the speaker 30 via a D / A converter, thereby controlling the output volume of each frequency band of the audio output by the speaker 30 based on the control value set by the output control value setting unit 113.

[0044] (Action and effect) As described above, the DSP amplifier 10 (audio output control device) according to one embodiment includes a minimum resonance frequency measurement unit 111, a state determination unit 112, an output control value setting unit 113, and an equalizer 13. The minimum resonance frequency measurement unit 111 measures the minimum resonance frequency fs when the speaker 30 outputs audio based on an input audio signal. The state determination unit 112 determines the degree of deterioration of the speaker 30 based on the minimum resonance frequency fs. The output control value setting unit 113 sets a control value for each frequency band of the audio signal input to the speaker 30 based on the degree of deterioration of the speaker 30. The equalizer 13 controls the output volume for each frequency band of the audio output by the speaker 30 based on the control value.

[0045] The DSP amplifier 10 can grasp how much the current lowest resonance frequency fs of the speaker 30 has changed from the product specifications, based on the current lowest resonance frequency fs of the speaker 30 and the speaker adjustment information of the speaker 30. This allows the DSP amplifier 10 to determine the degree of deterioration of the speaker 30. The DSP 10 can control the sound pressure for each frequency band of the audio signal input to the speaker 30, based on the degree of deterioration of the speaker 30, and can control the output volume for each frequency band of the audio output by the speaker 30. This allows the speaker 30 to output audio with stable sound quality, even if the lowest resonance frequency fs of the speaker 30 changes due to deterioration over time.

[0046] Moreover, the DSP amplifier 10 according to an embodiment further includes a storage unit 12. The storage unit 12 stores speaker adjustment information including a first frequency band for amplifying an audio signal, an amplification degree for amplifying an audio signal in the first frequency band, and a second frequency band for attenuating the audio signal, which are preset according to the deterioration degree of the speaker 30. The output control value setting unit 113 sets a control value for each frequency band of the audio signal input to the speaker 30, based on the deterioration degree of the speaker 30 and the speaker adjustment information.

[0047] The DSP amplifier 10 can set, without using complicated processing, a first frequency band for amplifying an audio signal input to the speaker 30, an amplification degree for amplifying the audio signal in the first frequency band, and a second frequency band for attenuating the audio signal according to the measured degree of deterioration of the speaker 30 based on the speaker adjustment information previously stored in the storage unit 12. This can reduce the load on the CPU 11 of the DSP amplifier 10 for setting the control values.

[0048] (Modification) Next, a modified example of the audio output control device according to the embodiment described above will be described. In the modified example of the audio output control device according to the embodiment, the storage unit 12 may further store the lowest resonance frequency fs as a product specification of the speaker 30 as a reference value, and the state determination unit 112 may determine the degree of deterioration of the speaker 30 based on the difference between the lowest resonance frequency fs and the reference value.

[0049] The storage unit 12 may store the minimum resonance frequency fs measured by the minimum resonance frequency measuring unit 111 as an initial value of the speaker 30 as a reference value of the minimum resonance frequency fs of the speaker 30. The minimum resonance frequency fs as an initial value of the speaker 30 is, for example, the minimum resonance frequency fs measured by the minimum resonance frequency measuring unit 111 for the first time after shipment. When the reference value of the minimum resonance frequency fs of the speaker 30 is not stored, the storage unit 12 stores the minimum resonance frequency fs measured by the minimum resonance frequency measuring unit 111 as a reference value. The storage unit 12 may store the minimum resonance frequency fs measured by the minimum resonance frequency measuring unit 111 as a reference value at the timing when it is detected that the user has instructed to store the reference value of the minimum resonance frequency fs by operating a button or the like.

[0050] In a modification of the audio output control device according to an embodiment, the state determination unit 112 calculates a difference value between the current lowest resonance frequency fs of the speaker 30 measured by the lowest resonance frequency measurement unit 111 and a reference value stored in advance in the storage unit 12. The state determination unit 112 determines the degree of deterioration of the speaker 30 based on the calculated difference value and the speaker adjustment information stored in advance in the storage unit 12.

[0051] The speaker adjustment information in a modified example of the embodiment will be described with reference to Fig. 6. First, the speaker adjustment information includes a criterion for determining the deterioration degree of the speaker 30, which is set in advance according to a difference value between the minimum resonance frequency fs measured by the minimum resonance frequency measurement unit 111 and the minimum resonance frequency fs as a reference value. In the example shown in Fig. 6, the reference value of the minimum resonance frequency fs of the speaker 30 is set to 110 Hz.

[0052] In the example shown in FIG. 6, the state determination unit 112 determines, based on the speaker adjustment information, that the degree of deterioration of the speaker 30 is “low” if the difference between the measured current lowest resonance frequency fs of the speaker 30 and the reference value is 10 Hz or less, “medium” if the difference is between 10 Hz and 20 Hz, and “high” if the difference is 20 Hz or more.

[0053] The speaker adjustment information further includes an amplification frequency band (first frequency band) for amplifying the digital audio signal input to the speaker 30, which is preset according to the degree of deterioration of the speaker 30, an amplification degree for amplifying the digital audio signal in the amplification frequency band, and an attenuation frequency band (second frequency band) for attenuating the digital audio signal.

[0054] In the example shown in FIG. 6, the output control value setting unit 113 sets the control value of the digital audio signal based on the speaker adjustment information so that when the degree of deterioration of the speaker 30 is “low”, the audio signal input to the speaker 30 is not amplified, and the audio signal is attenuated in the frequency band below the reference value of 110 Hz.

[0055] In addition, when the degree of deterioration of the speaker 30 is "medium", the output control value setting unit 113 sets the control value of the digital audio signal so that the audio signal is amplified by 5 dB in the frequency band above 100 Hz and attenuated in the frequency band below 100 Hz.

[0056] Furthermore, when the degree of deterioration of the speaker 30 is "high", the output control value setting unit 113 sets the control value of the digital audio signal so as to amplify the audio signal by 10 dB in the frequency band above 90 Hz and attenuate the audio signal in the frequency band below 90 Hz.

[0057] Note that the various pieces of information included in the speaker adjustment information may be set in advance based on the minimum resonance frequency fs serving as a reference value of the speaker 30. Note that in a modified example of the embodiment, the speaker adjustment information is set based on the difference between the minimum resonance frequency fs serving as a reference value of the speaker 30 and the current minimum resonance frequency fs of the speaker 30, and therefore does not necessarily need to be stored for each product specification of the speaker 30.

[0058] The output control value setting unit 113 outputs the control value of the digital audio signal to the equalizer 13. The equalizer 13 amplifies or attenuates the sound pressure of each frequency band of the digital audio signal to correct the digital audio signal based on the control value set by the output control value setting unit 113. The equalizer 13 outputs the corrected digital audio signal to the speaker 30 via a D / A converter, thereby controlling the output volume of each frequency band of the audio output by the speaker 30 based on the control value set by the output control value setting unit 113.

[0059] (Effects of Modifications) As described above, in a modified example of the DSP amplifier 10 (audio output control device) according to an embodiment, the storage unit 12 further stores the lowest resonance frequency fs as a reference value of the speaker 30. The state determination unit 112 determines the degree of deterioration of the speaker based on the difference between the currently measured lowest resonance frequency fs and the reference value stored in the storage unit 12.

[0060] The DSP amplifier 10 according to one embodiment calculates the difference between the lowest resonance frequency fs as a reference value of the speaker 30 and the currently measured lowest resonance frequency fs of the speaker 30, and can determine the degree of deterioration of the speaker 30 based on the calculated difference value. The DSP amplifier 10 according to one embodiment determines the degree of deterioration of the speaker 30 using the difference between the lowest resonance frequency fs as a reference value of the speaker 30 and the currently measured lowest resonance frequency fs of the speaker 30, and therefore may be able to handle cases where the product specifications of the speaker 30 are different, and can be applied to a greater number of speakers 30.

[0061] As described above, an embodiment of the present invention has been described, but the descriptions and drawings forming a part of this disclosure should not be understood as limiting this invention. In one embodiment, the audio output control device is configured as a DSP amplifier 10, but the audio output control device may be configured as a separate audio processing device different from the DSP amplifier. The process of controlling the sound pressure of each frequency band of the audio signal based on the control value set by the output control value setting unit is not limited to digital audio signal processing by the equalizer 13, and may be performed by analog audio signal processing, for example. Various alternative embodiments, examples, and operation techniques will be apparent to those skilled in the art from this disclosure. [Explanation of symbols]

[0062] 10 DSP amplifier (audio output control device) 13. Equalizer 30 Speaker 111 Lowest resonant frequency measurement section 112 Status determination unit 113 Output control value setting unit

Claims

1. a minimum resonance frequency measuring unit that measures a minimum resonance frequency when the speaker is outputting sound based on an input audio signal; a state determination unit that determines a degree of deterioration of the speaker based on the lowest resonance frequency; an output control value setting unit that sets a control value for each frequency band of an audio signal input to the speaker based on a deterioration degree of the speaker; an equalizer that controls an output volume for each frequency band of the sound output by the speaker based on the control value; An audio output control device comprising:

2. The speaker adjustment information includes a first frequency band for amplifying the audio signal, an amplification degree for amplifying the audio signal in the first frequency band, and a second frequency band for attenuating the audio signal, the first frequency band being preset according to a deterioration degree of the speaker, and a storage unit configured to store the speaker adjustment information; The output control value setting unit sets a control value for each frequency band of the audio signal input to the speaker based on a deterioration degree of the speaker and the speaker adjustment information. The audio output control device according to claim 1 .

3. The storage unit further stores a minimum resonance frequency of the speaker as a reference value, The state determination unit determines a degree of deterioration of the speaker based on a difference between the currently measured lowest resonance frequency and the reference value stored in the storage unit. The audio output control device according to claim 2 .

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