KR20200011841A - Apparatus and method for auditory management, and apparatus for attenuating noise at sound signal inputted from one microphone - Google Patents

Abstract

A hearing management device disclosed in the present invention includes: an acoustic range determining unit which determines an ambient sound within a predetermined range from a reference sound when the predetermined reference sound specialized for a subject is set; an output time determining unit which determines an output time for each sound for outputting each of the reference sound and the ambient sounds; an acoustic time matching unit for generating sound output control information by matching the output time for each sound to each of the reference sound and the ambient sounds; and an output sound generating unit for generating an auditory management sound to be output to a speaker based on sound output control information.

Description

Hearing management device and method, and a device for attenuating the noise of a single microphone voice signal having a hearing management function, and APPARATUS FOR ATTENUATING NOISE AT SOUND SIGNAL INPUTTED FROM ONE MICROPHONE}

The present invention relates to an apparatus and method for managing hearing, and more particularly, to an apparatus and method capable of improving or protecting a hearing function by outputting sound of a frequency specialized to a subject. The present invention also relates to a device for attenuating noise of a single microphone voice signal capable of implementing a hearing management method.

A method and apparatus for stimulating auditory cells using acoustic signals capable of improving hearing, ringing such as tinnitus, and hearing loss are disclosed. Korea Patent Registration No. 10-0963888 (2010.06.08.) (Hereinafter referred to as the prior art).

In the prior art, a sound signal is provided at a resolution of 1 / k octave to determine a user's hearing threshold, and based on the determined hearing threshold, a frequency of the damaged auditory cell region is determined, and a predetermined intensity of a corresponding target frequency band is determined. By outputting an acoustic signal, the user's auditory cells are stimulated.

However, in the prior art, an object is to intensively stimulate a specific auditory cell region by intensively outputting one sound of a specific frequency band. However, intensive stimulation of only a specific auditory cell region may result in a deviation of the sensing ability between the intensively stimulated auditory cell region and the surrounding auditory cell region.

Moreover, in practice, if one sound of a specific frequency band for intensive stimulation is continuously output, the user may only adapt the sound to be output and there is a problem in the overall stimulus effect.

In addition, the prior art describes that an acoustic signal is composed of one or a combination of amplitude modulated sound, frequency modulated sound, pulsed sound, continuous sound, and amplitude modulated narrowband noise, but no specific method is described.

The present invention further goes beyond the prior art as described above, which stimulates only a very narrow narrowband portion in the audible region of the auditory structure, or gives a broad range of stimulation for all regions, further sequentially sweeping sounds in the vicinity of a particular region. By applying a change in a random (Random) method and to improve the hearing management effect.

The hearing management device according to an embodiment of the present invention may include: an acoustic range determiner configured to determine an ambient sound within a predetermined range from the reference sound when a predetermined reference sound specialized for the subject is set; An output time determiner configured to determine a sound output time for outputting each of the reference sound and the ambient sound; An acoustic time matching unit configured to generate sound output control information by matching the output time of each sound with each of the reference sound and the ambient sound; And an output sound generator for generating an auditory management sound to be output to the speaker based on the sound output control information.

Here, the frequency of the reference sound and the ambient sound is characterized by being calculated by the formula of {(reference frequency) × 2 ^ (M / L)}. In this case, M represents the Mth scale from the reference frequency, and L represents the number of scales to distinguish one octave from the reference frequency.

In addition, the reference sound and the ambient sound may be selected based on the scale of the piano.

In addition, the peripheral sound may be selected from the scales in the 1 / K octave range (where K may be one of 1, 2, 1/2, 1/4) from the reference sound.

Meanwhile, the sound range determiner divides the audible sound frequency range into a plurality of bands in which a range is partially overlapped with each other in a predetermined one octave unit, and when a specific band including the set reference sound is specified, All scales or some scales included in the band may be selected as the ambient sound.

The output time determiner may include a sweep output time for each sound to output each sound and a sequence of frequencies of the reference sound and the ambient sound in a sweep method of sequentially outputting the reference sound and the ambient sound according to the frequency order. The random output time for each sound to be output may be determined in a non-sequential random method that does not follow.

At this time, the sound sweep output time is, in the sweep method, a minimum time or more to the extent that the presence of each sound is output, or less than a maximum time not to recognize that each sound is cut off, Can be determined.

In addition, the auditory management sound is configured to be output according to a method of arbitrarily mixing the sweep method in which the reference sound and the ambient sound are sequentially output in a frequency order and a random method that is not sequentially output in a frequency order. Can be.

According to still another aspect of the present invention, there is provided a hearing management method, comprising: determining an ambient sound within a predetermined range from a reference sound when a predetermined reference sound specialized for a subject is set; Determining a sound output time for outputting each of the reference sound and the ambient sound; Generating sound output control information by matching the tone output time to each of the reference sound and the ambient sound; And generating an auditory management sound to be output to a speaker based on the sound output control information and applying it to the subject.

The reference sound and the ambient sound may be selected based on the scale of the piano.

The determining of the sound output time may include determining a sound sweep output time for outputting each sound in a sweep method of sequentially outputting the reference sound and the ambient sound according to the frequency order, The method may further include determining a random output time for each sound to output each sound in a random manner in which the peripheral sound is output in a non-sequential manner not following a frequency order.

The generating of the auditory management sound may be performed by randomly mixing a sweep method in which the reference sound and the ambient sound are sequentially output in the order of frequencies and a random method in which the non-sequential output is not followed. The auditory management sound may be generated to be output.

According to another embodiment of the present invention, an apparatus having a hearing management function and attenuating periodic noise from a voice signal by a single microphone includes: detecting a periodic signal from a signal obtained by digitally converting a voice introduced into the single microphone; A periodic sound attenuation control unit that outputs a signal in which the periodic signal is attenuated by mixing an inverted phase of the periodic signal with the digitally converted signal; An adaptive level range controller for controlling the level of the attenuated signal to output a level-adapted signal; An attenuation adjustment selection unit for mixing one or all of the signal from which the periodic signal output from the periodic sound attenuation control unit is attenuated and the level-adapted signal output from the adaptive level range control unit to output the processed audio signal; When a predetermined reference sound specialized for the subject is set, an ambient sound within a predetermined range is determined from the reference sound, a sound output time for outputting the reference sound and each of the ambient sounds is determined, and the reference sound and the ambient sound are determined. An auditory manager configured to generate sound output control information by matching the respective output times with sounds, and to generate a hearing management sound to be output to a speaker based on the sound output control information; And a signal selector configured to provide at least one of the processed voice signal or the auditory management sound to a speaker.

The periodic sound attenuation control unit may include: a signal block sum processing stage configured to process the digitally converted signal as a positive signal; A signal block sum inverse processing stage for processing the positive signal into an inverse phase that is in antiphase; By calculating a resultant signal with the positive signal to determine the periodic signal, by generating arbitrary adaptive Fir Filter coefficients separated for each frequency in order to attenuate the determined periodic signal, the coefficients are weighted and applied to the inverse signal. The method may further include an adaptive Fir Filter LMS stage for repeating processing of the attenuated signal of the periodic signal, which is the resultant signal.

In addition, the apparatus having an auditory management function and attenuating periodic noise from a voice signal by a single microphone may be used to detect a frequency at which a feedback oscillation sound exists from the processed voice signal output from the attenuation adjustment selector. A signal analyzer for analyzing the frequency components of the processed speech signal to generate spectral information; And a sound matching unit for analyzing a frequency including feedback oscillation from the spectral information and filtering the analyzed frequency from the digitally converted signal to output a matched signal. The attenuated signal, the level-adapted signal, and one or more mixed signals of the matched signal may be output.

Further, the hearing management unit, the sweep output time for outputting each sound in the sweep method of sequentially outputting the reference sound and the ambient sound in order of frequency, the reference sound and the ambient sound does not follow the frequency order Determining a random random output time for outputting each sound in a non-sequential random method, and outputting the reference sound and the peripheral sound in the sweep method according to the negative sweep output time; The hearing management sound may be generated by arbitrarily combining the output in the random manner with time.

According to the present invention including the above-described configuration, the auditory management is variously applied to the subject by a variety of sweep and random methods of auditory management sound including not only a specific frequency requiring an auditory stimulus but also a near frequency region around the frequency. Maximize the effect.

In addition, since it is possible to attenuate the ambient noise from the voice signal input through one microphone, the problem that the voice signal is distorted as the voice signals from two or more microphones are mutually processed and causes additional noise when processing the voice signal. It is possible to provide a noise reduction device that can solve the problem. In particular, it is possible to provide an apparatus capable of simultaneously or selectively providing such a noise reduction function and hearing management function.

1 is a block diagram showing the configuration of a hearing management device according to the present invention.
2 is a view for explaining the sound range determination unit in more detail.
3 is a view for explaining the output time determiner in more detail.
4 is a view for explaining the sound time matching unit in more detail.
5 is a view for explaining the output sound generator in more detail.
6 is a flowchart illustrating a hearing management method according to the present invention.
FIG. 7 is a block diagram illustrating a configuration of an apparatus for attenuating noise of a single microphone voice signal having an auditory management unit that implements the auditory management function as described above.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the device and method for hearing management according to the present invention, and a device for attenuating the noise of a single microphone voice signal with a hearing management function. For reference, terms referring to each component of the present invention are named by way of example in consideration of their functions, and thus, the technical contents of the present invention should not be predicted and limited by the term itself.

First, with reference to the block diagram of Figure 1, the configuration of the hearing management apparatus according to an embodiment of the present invention will be described. Referring to the drawings, the hearing management apparatus 200 may include a sound range determination unit 210 that determines an ambient sound within a predetermined range from a set reference sound when a predetermined reference sound specialized for a target person is set, and the set reference sound and the determined surrounding sound. An output time determiner 220 that determines the output time of each sound for outputting each of the sounds, and an acoustic time matcher 230 that generates sound output control information by matching the output time of each sound to the reference sound and the surrounding sounds, respectively. And an output sound generator 240 for generating an auditory management sound to be output to the speaker based on the sound output control information.

In the present invention, the frequency of the ambient sound that can be determined from the reference sound can be calculated by the following equation.

(Frequency of each ambient sound) = {(reference frequency) × 2 ^ (M / L)}

Here, M may be an integer representing the Mth scale from the reference frequency. If M is a positive scale, it may be a scale from the reference frequency in a high direction (high pitch direction), and if M is a negative scale, it may be a scale from a reference frequency in a low direction (bass scale). L represents the number of musical scales to classify the frequency in the range of one octave from the reference frequency, and may be a natural number.

In particular, the present invention can use a sound based on the scale of the piano. Based on the piano scale, it can be interpreted to use the frequency defined in each scale of the piano defined based on A4 = 440 Hz when determining the frequency of each note.

Thus, when an arbitrary reference frequency is input, it is possible to select the piano scale that is closest to the reference frequency (for example, the frequency value is closest) and determine it as the reference sound, and a few notes in the high pitch direction around the reference sound. And / or by selecting a few scales in the bass direction, it is possible to simply select a peripheral sound in a desired range.

If the reference frequency exceeds the frequency of the existing piano scale (e.g., the frequency is higher than the frequency of the 88th note of the 88th scale), a virtual piano scale is constructed by using the above formula and the reference sound and And / or determine ambient sounds.

It is also possible to use more subdivided scales, such as those based on piano scales but divided into 24 scales per octave, or even subdivided into 6 scales per octave.

Selecting a reference frequency may be determined by a person who wants to manage hearing by arbitrarily designating a desired frequency value or by searching for a frequency that needs to be managed using a professional measuring device. According to the present invention, even if a specific reference frequency is selected, various frequency portions in the periphery thereof can be managed together, so that the subject may incorrectly specify the reference frequency without using specialized equipment.

The reference frequency may be selected by specifying one specific frequency value or by specifying a frequency range, or by specifying a specific piano scale.

Alternatively, selecting a reference frequency may include specifying a band containing the reference frequency and specifying a section most relevant to the reference frequency within the designated band.

For example, the audio frequency band may be divided into 12 bands as shown in [Table 1]. Each band consists of a period (i.e., one octave) up to its starting frequency and twice its frequency.

Band number (BN) Frequency range B1 200 to 400 Hz B2 300 to 600 Hz B3 500 to 1k Hz B4 750 to 1.5k Hz B5 1k to 2k Hz B6 1.5k to 3k Hz B7 2k to 4k Hz B8 3k to 6k Hz B9 4k to 8k Hz B10 5k to 10k Hz B11 6k to 12k Hz B12 7k to 14k Hz

Each band may be divided into a predetermined number of sections by the following equation.

(Frequency of each section) = {(starting frequency) × 2 ^ (M / L)}

Here, M represents the M-th section from the start frequency, L represents the number of sections to distinguish one octave constituting the band. There are usually 12 sections.

And, for example, if the subject specifies band 3 and section 3, the reference frequency may be determined as {(500) × 2 ^ (3/12)} = 594.6 Hz.

On the other hand, as a method that can be applied in this designation method, when the subject designates only the band, the upper 1/2 octave to lower 1/2 octave range (1 in total) based on the entire frequency range of the band or the start frequency of the band. Octave range) to generate and output auditory sound, and if the subject specifies a band and section, the range of upper 1/4 octave to lower 1/4 octave (total 1/2 octave range) It may be implemented to generate and output the hearing management sound.

Or, similarly, if only a band is specified, the frequency of the 12 sections constituting the band is output as ambient sound, and if a section along with the band is specified, a section having a total range of 1/2 octave based on that section It is also possible to control the frequency of these to be output as ambient sound.

Alternatively, when only a band is designated, the frequencies of all 12 sections constituting the band may be selected as an ambient sound, and the selected ambient sound may be output in a swept manner. On the other hand, if both a band and a section are specified, the section is referred to as the reference sound, and all surrounding sounds of the band are output in a swept manner, and alternately, the surrounding sounds up to 1/4 octave and the lower quarter are made. Ambient sound up to octave can be configured to be output in a random manner. The sweep method and the random method will be described later.

Regarding the way of specifying the band and section, in another example of selecting the reference frequency, suppose that the subject specified 1.5 kHz and section 5. Here, it is assumed that the section per octave can be divided into 12, and if the section is specified along with the band, it is set to select the ambient sound in the total 1/2 octave range based on the section. If so, in Table 1, B4, B5, and B6 may be selected as candidate bands. On the other hand, since section 5 is specified, the reference frequency is 2002 Hz, so B6 can be selected. Subsequently, all ambient sounds of the selected band B6 may be output in a swept manner. And alternately, the reference sound having section 5 as the reference frequency and the surrounding sounds selected as the notes up to 1/4 octave and the notes up to 1/4 octave therefrom may be output in a random manner.

On the other hand, the present invention is a sweep method for sequentially outputting the sound (reference sound and ambient sound) determined as the auditory management sound within a predetermined octave in ascending or descending order of frequency, and a random order that does not follow the ascending or descending order of frequency. Alternatively, the output may be performed in a random manner in which high and low sounds are output in an arbitrary non-sequential order.

In addition, each scale output in the sweep scheme and / or the random scheme may be output for any predefined time. For example, the time at which each scale is output may be determined about 20 to 500 ms. The output time of each scale may be variously determined according to the order of output within each scheme according to the output scheme of whether to be output in a swept manner or a random manner according to the frequency of the scale.

At this time, the output time is, for example, the sweep time, or more than the minimum time for the recognition that each of the sequentially output sound is output, and / or the degree that each of the sequentially output sound is not recognized as being cut off Can be determined to be less than or equal to the maximum time of In addition, the random method may be determined to be equal to or more than a minimum time for recognizing that each sound is output, and / or less than a maximum time that causes a discomfort or a hearing management effect to the subject.

The hearing management apparatus 200 may provide an interface (not shown) so that a subject may designate a band and / or a section, a reference frequency, a frequency range, and the like. In addition, the subject may set and adjust various parameters of the hearing management apparatus 200 through the interface, such as band and section division, an output method of auditory management sound, and an octave range for selecting an ambient sound in each output method. will be.

2 is a view for explaining the sound range determination unit in more detail. When the subject inputs at least a reference frequency, the sound range determination unit 210 may determine the reference frequency or the reference sound and determine the ambient sound within a predetermined 1 / K octave range around the reference frequency or the reference sound. Herein, K may be any number, and the octave range may be set to 4, 2, 1, 1/2, and the like.

Also, the sound range determiner 210 may determine an output order (sequence) in the sweep method and / or the random method of the reference sound and the selected ambient sound.

3 is a view for explaining the output time determiner in more detail. The output time determiner 220 may determine the output time for each output method of the set reference sound and the ambient sound. For example, each note of the swept method may be determined sequentially in the range of 50 to 500 ms or randomly output time (swept sweep output time) may be determined, and each note of the random method may be sequentially selected in the range of 20 to 160 ms. The output time (negative random output time) may be determined to vary or randomly.

4 is a view for explaining the sound time matching unit in more detail. The acoustic time matching unit 230 configures a series of information (acoustic output control information) by matching the information related to each sound in which a specific order is set with the output time information determined in relation to each sound.

5 is a view for explaining the output sound generator in more detail. The output sound generator 240 may configure an analog signal (ie, hearing management sound) by modulating arbitrary sample sounds in accordance with the sound output control information. Alternatively, a certain sine wave may be used as a sample sound and modulated to configure a hearing management sound. The hearing management sound may be applied to earphones, headphones, sound pressure output devices, bone conduction speakers, or the like, and may be output to the subject. In addition, the hearing management sound may be generated as a left ear or a right ear, respectively.

The output sound generator 240 may generate a sound to be provided in a swept manner and a sound to be provided in a random manner, and output the alternating sounds in a random order. It is also possible to insert a blank time when outputting each method, or output continuously without a blank.

6 is a flowchart illustrating a hearing management method performed by the hearing management apparatus according to the present invention.

The hearing management apparatus 200 may receive a reference frequency value through an interface (S10). The reference frequency may be designated by receiving a band and / or a section. Even instead of receiving the reference frequency value, the reference sound may be selected immediately.

When the reference frequency is input, the reference sound may be determined (S20). The reference sound may be the reference frequency itself or may be determined in the piano scale, which is the frequency closest to the reference frequency. In addition, a 1 / K octave upper and lower ranges of the reference sound may be set, and any number of surrounding sounds may be determined within the set range. The ambient sound may be determined from up to N high notes and up to N ′ low notes from the reference sound. N and N 'may be the same number or different numbers. In this case, the sounds for output in a swept manner and the sounds for output in a random manner may be determined to be the same or different from each other.

Subsequently, the determined reference sound and / or the ambient sound determine the output time for each sound to be provided as a real sound to the subject (S30). The sound output time may be determined to be identical to or different from each sound output time (sound sweep output time) to be output by the sweep method and each sound output time (sound random output time) to be output by the random method.

Matches the sequence of reference sound and ambient sound to be output by the sweep method and the sweep output time for each sound, and matches the sequence of reference sound and ambient sound to be output by the random method and the random output time for each sound, thereby outputting sound for each output method The control information is generated (S40).

Based on the sound output control information for each output method, it generates a hearing management sound for each output method, and outputs the hearing management sound through the speaker in the order of the output method (S50).

In addition, the present invention provides an apparatus for attenuating noise of a single microphone voice signal having an auditory management function implemented by the auditory management apparatus as described above. The configuration of this noise reduction device is shown in FIG.

An apparatus for attenuating noise of a single microphone voice signal having a hearing management function according to the present embodiment includes a microphone input impedance matching and signal conversion unit 100, a sound matching unit 110, a periodic sound analysis and attenuation control unit. 120, adaptive level range control unit 130, attenuation adjustment selector 140, spatial voice position control unit 150, signal analysis unit 160, main gain amplifier 170, system It includes an operation unit 190. In addition, the hearing management apparatus as described above has been added as a component named hearing management unit 200.

In particular, the processed voice from the spatial voice position controller 150 and the hearing management sound from the hearing manager 200 may be selectively provided to the main gain amplifier 170 by the signal selector 195.

Detailed configuration of the components will be described later.

The microphone input impedance matching and signal converter 100 matches the input from the single microphone with the impedance of the noise reduction device. In addition, an inflow signal (that is, a signal mixed with an audio signal and an ambient signal), which is an analog signal generated by one microphone, is converted into a digital signal. The microphone input impedance matching and signal converter 100 includes an input impedance matching function and an A / D conversion function. The incoming signal from the microphone is an analog signal and contains not only voice but also ambient noise. The input impedance matching function realizes maximum power transfer of the incoming signal.

The sound matching unit 110 generates a mixed signal by selecting one of a frequency signal generated from a microphone to generate a digitally converted signal and a sound of an arbitrary specific frequency band. The mixed signal is output as a matched signal after the tone is adjusted for each frequency band.

In addition, a separate external signal, which does not flow from the microphone, may be input to the sound matching unit 110. This external signal can be mixed with the digital signal. The external signal may be a signal transmitted from another headset or earset.

The sound matching unit 110 may select one or more of a digital signal output from the microphone input impedance matching and signal conversion unit 100, an external signal, and a signal generated through a signal generation function of the sound matching unit 110. It has a signal selection mix and a mux function to select and mix. In addition, the signal output from the signal selection mix and mux function is converted into a matched signal through the tone and feedback oscillation adjustment function.

The noise reduction device receives an external signal and processes the noise reduction process together with the microphone input signal to listen together. This attenuates the noise even when receiving a signal with no noise attenuation from another headset or earset, so that only a clean voice can be heard. In particular, this functionality is useful when multiple headsets or earsets are in communication with each other.

The signal generation function controls the signal conversion characteristics and the tone according to the microphone type, preprocessing unnecessary sound sources, adjusting the triggering of feedback from the system, and correcting the voice to be listened to to the desired tone. Occurs. That is, the signal generation function generates and outputs a sound having a specific frequency, and allows the listener to manually adjust the volume of the sound of the frequency as desired, thereby adjusting the tone / volume for each frequency according to the hearing characteristics of the listener. Done.

The signal output from the signal selection mix and mux function may be any one of a single output of the microphone input signal, a mixed output of the microphone input signal and an external signal, and a single output of the signal output from the signal generation function.

The single output of the microphone input signal is for noise attenuation only for the signal converted through the microphone and digitally converted. Mixing and outputting a microphone input signal and an external signal is for mixing and processing a voice signal introduced through a microphone and digitally converted and transmitted from another headset or earset. The single output of the signal generated by the signal generation function is to tune a tone of a desired frequency from the voice signal, and to adjust the volume of each frequency band of the voice that the listener hears through the speaker according to his or her hearing characteristics. Is selected when.

The tone and feedback oscillation adjustment function may be composed of a plurality of filters (Filter1, Filter2, Filter3 ... FilterN). Multistage filters are arranged for the purpose of tuning the tone of the desired frequency and controlling the frequency at which the feedback oscillation occurs, for preprocessing to control the tone of the desired frequency and to remove unnecessary sound sources. The matched signal = {gN FilterN} × Xm (n).

The control amount of each filter can be adjusted by the gains g1, g2, g3 ... gN. The gain of each filter may be adjusted by a control command provided by the system operating unit 190 (a control command instructing to control a feedback oscillation sound of a specific frequency).

Each filter may include a notch filter, a shelf filter, a peak filter, or the like.

The periodic sound analysis and attenuation control unit 120 detects and attenuates only a periodic signal having a periodic waveform pattern from the matched signal output from the sound matching unit 110. In the present invention, the periodic signal is determined as noise.

The periodic sound analysis and attenuation control unit 120 receives, as an input, a matched signal whose tone is controlled through the sound matching unit 110, preprocessing for removing unnecessary sound sources, and feedback generation is controlled. Then, a noise attenuated signal in which only a periodic signal is attenuated among the signal components constituting the matched signal is output.

The periodic sound analysis and attenuation control unit 120 includes a signal block sum processing function, a signal block sum processing function, and an adaptive Fir Filter LMS function. LMS stands for Least Mean Square processing.

The Fir Filter LMS function obtains an active coefficient, which is a result weight according to the LMS process, and applies it to a Fir Filter coefficient to be adapted. The adaptive Fir Filter coefficients are controlled by active coefficients, which are the resultant weights of the LMS process, and the T _period , G _weights may be provided from the system operator 190 or may be generated by the Fir Filter LMS function itself. As a result, the cyclic signal processing of the signal block sum processing function, the signal block sum processing function, and the adaptive Fir Filter LMS function of the periodic sound analysis and attenuation control unit 120 is performed. The adaptive Fir Filter LMS function generates an error signal. The adaptive Fir Filter coefficient is modified and iterated until the error signal becomes zero.

The tap filter generates a tap delay. After the weights W ₀ (n) to W _m (n) are applied to each tap, the fir filter determines a periodic signal (or an error signal) from the LMS result. The noise is attenuated by adjusting the active coefficient repeatedly until the periodic signal becomes zero.

When the periodic signal becomes zero, it means that the periodic peripheral signal, that is, the surrounding noise, is mostly attenuated.

In processing the matched signal output from the sound matching unit 110, the periodic sound analysis and attenuation control unit 120 includes a signal block sum processing function, a signal block sum reverse processing function, and an adaptive Fir Filter LMS function. Various paths can be combined to generate and output a signal with noise attenuation.

The signal block sum processing function obtains an error signal by comparing a block unit positive signal for periodic signal recognition with a periodic noise attenuation signal.

The signal block sum inverse processing function reflects an LMS active coefficient according to an error signal in a block unit inverse signal for periodic signal recognition.

As a result, when the error signal approaches zero by active signal processing the positive signal and the reverse signal, a noise attenuated signal including only the aperiodic signal is generated.

The reason for using the fir filter in the present invention is to maintain the linear phase of the signal to be noise attenuated, and since the fir filter has linearity, when the reverse phase of the periodic signal is mixed, the periodic signal can be linearly removed. .

The periodic sound analysis and attenuation control unit 120 minimizes a signal perceived as an error of the mean square using an active algorithm.

Here, the part recognized as an error signal is (error signal) = (block unit positive signal) + (periodic noise reduction signal). Here, assuming that the transfer function of the signal block sum processing function is Hs (n) and the transfer function of the signal block sum processing function is H's (n),

(Block unit forward signal) = (matched signal) x Hs (n), and (block unit reverse signal) = (matched signal) x H's (n).

After all, (error signal) = (block unit constant signal) + (periodic noise attenuation signal), taking the root mean square of the active algorithm, it is summarized as follows.

▽ ² (error signal) = 2 (error signal) × (d (error signal) / dW (n))

= 2 (error signal) × d {(block unit positive signal) + ((block unit reverse signal) × [W _m (n)] _T )} / dW (n)

That is, the block unit jeongsinho and blocks reverse signal, so each signal in the reverse phase relations, [W _m (n)] Do [W _m (n)] _T periodically cancel each other out processing of by the active factor vector table as _T The error signal will be close to zero, and finally only the non-periodic signal can be reproduced in the periodic noise attenuation signal.

On the other hand, the LMS active algorithm can usually eliminate the periodic signal. However, it is necessary to determine how far to view the periodic signal and to determine how much to cancel the determined periodic signal.

This determination can be adjusted by the system operation unit 190 controlling T (period) and G (weighting) applied to the signal block sum processing function, the signal block sum processing function, and the adaptive Fir Filter LMS function.

As the degree of cancellation of the periodic signal from the speech signal increases, the noise causing the afterimage effect increases. So, in order to solve this side effect, the following adaptation level range controller 130 is applied.

The adaptive level range controller 130 determines a tone compensation process and a level scale range by using a signal provided from the periodic sound analysis and attenuation controller 120, that is, a signal from which a periodic signal (noise) is attenuated, and then applies a level-adapted signal. Perform the function of printing.

First, the preprocessing gain is adjusted to generate a preprocessed signal (preprocessed signal) to further filter the periodicity-causing factor in the signal in which the periodic signal is attenuated.

This preprocessed signal is converted into a level-adapted signal by performing a tone compensation process and a level adaptive curve control process for adjusting the level scale range, and again correcting the post-processing gain to compensate for the periodicity-inducing component.

When the voice signal passes through the periodic sound analysis and attenuation control unit 120, a signal attenuated about a periodic component (ie, a periodic noise attenuation signal) is output, and the adaptive level range control unit 130 remains in the periodic noise attenuation signal. It will deal with the induced noise part.

The adaptive level range control unit 130 is configured to include a gain preprocessing function, a level control curve control function, and a gain postprocessing function. Gain preprocessing and gain postprocessing are applied to level the signal. The level adaptive curve control function is applied to process at least part of the induced noise portion.

The level adaptive curve control function includes a cascaded multistage filter (Filter1, Filter2 ... FilterN) and a gain slope control function in order to attenuate the induced noise unintentionally added by the processing in the periodic sound attenuation control unit. It is configured by.

The periodic noise attenuation signal passes through the adaptive level range control unit 130, whereby the volume control, after-image noise control, and the level of the frequency band in which the induced noise appears are controlled to become a level-adapted signal. The level-adapted signal is processed as follows. (Level-adapted signal) = (preprocessing gain) × [gN FilterN] × GSC × (postprocessing gain). Here, [gN FilterN] is for controlling the level of the frequency band in which the induced noise appears, and may be configured as a notch filter, a chef filter, a peak filter, and the like.

In the gain slope control function, afterimage noise control processing is performed by controlling the distortion of the sound wave according to Attack, Release, Sustain, and Decay Time, which controls the time deformation of the sound, and the gain slope according to the height of the volume.

The attenuation adjustment selector 140 may include a matched signal output from the sound matching unit 110, a signal from which a periodic signal output from the periodic sound analysis and attenuation control unit 120 is attenuated, and the adaptive level range control unit 130. A level-adapted signal output from is output alone or weighted mixed of two or more to generate a processed speech signal.

The attenuation control selector 140 is a tone-controlled signal through the sound matching unit 110 and the unnecessary sound source (ie, feedback oscillation) is removed (ie, a matched signal), the periodic sound analysis and attenuation control unit 120. The signal in which the periodic component is processed (that is, the noise attenuated signal) and the signal in which the volume control, the after-image noise control, and the induced noise frequency band are controlled through the adaptive level range control unit 130 (that is, the level adaptive signal) Are respectively provided with input terminals for receiving input, and select one or a plurality of signals and output a final processed voice signal.

Amplification stages G1, G2, and G3 for gain adjustment for each of the input signals and switches sw1, sw2, and sw3 for selecting a signal input may be disposed at each input terminal of the attenuation adjustment selector 140. Can be. The signals selected by the switches are mixed and output at the mix stage.

The processed speech signal, which is a resultant signal selected and mixed by the amplifying stages G1, G2, G3 and the switches sw1, sw2, sw3, is expressed as follows.

(Processed speech signal) = (G1 × sw1 × (level adapted signal)) + (G2 × sw2 × (periodic noise attenuation signal)) + (G3 × sw3 × (matched signal)). At this time, the gain of the amplifier stage can be adjusted according to the desired degree of noise attenuation.

Conventional noise attenuation devices merely fix the amplification gain of the signal and only turn it on / off, making it difficult to adapt to changes in the surrounding environment and to meet the needs of the listener. However, the noise attenuation apparatus according to the present invention uses the amplification stages G1, G2, G3 and the switches sw1, sw2, sw3 of the attenuation control selector 140 to variously select a signal and attenuate the noise. As the degree can be varied, it is possible to effectively meet the surrounding environment and listening needs.

As an example of the control operation, when the noise attenuation degree is turned off, only the matched signal can be output by setting only (processed speech signal) = (G3 x sw3 x (matched signal)). At this output, voices with a controlled tone and feedback oscillation can be heard.

In addition, when the attenuation degree is turned on, (processed speech signal) = (G1 × sw1 × (level-adapted signal)) + (G2 × sw2 × (periodic noise attenuation signal)) + (G3 × sw3 × (matching) Signal)), G1 = 0, G2 = α, G3 = β, and sw1 can be selected from Off, sw2 and sw3 can be selected from On or Off. As a result, the periodic noise reduction signal and the level-adapted signal after the noise reduction are mixed and output. At this output, voices and feedback oscillations are controlled, periodic noise is attenuated, and levels are adjusted.

On the other hand, if you want to listen to the emotional voice by accommodating the noise of the original sound to some extent, by setting G1 to 0 or less, which is a slight weight, you can also listen to a mixture of signals from which the noise is not removed. .

The spatial voice position control unit 150 generates a spatial sound by arranging the position of the sound source in a virtual space based on the listener using the noise attenuated voice signal (ie, the processed voice signal). In the case of one microphone input voice signal, the listener can recognize that the sound source is located between both eyes of the listener. Accordingly, the listener may feel strabismus and dizziness.

The spatial voice position control unit 150 converts the processed voice signal into an analog signal to be input to the left speaker and an analog signal to be input to the right speaker so as to produce an effect such that the sound source is three-dimensionally arranged in the space surrounding the listener. do. This allows the listener to listen in a stable and comfortable manner.

That is, as the spatial voice position controller 150 controls the processed voice signal output through the attenuation adjustment selector 140, the spatial voice position controller 150 between the spatial sense recognized from the voice signal and the visual sense recognized by the spatial sense. It is possible to solve the disparity that may appear, that is, the overlapping of sound images and vision. As a result, the visual fatigue of the listener is reduced, and pain and dizziness of the ears and the head do not occur even when the voice signal is listened to for a long time.

In this way, the spatial voice position control unit 150, which performs a function of converting a voice signal input by only one microphone into stereo sound in a space, processes the signal using the principle of a HRTF (Head Related Transfer Function). Done. To this end, the spatial voice position control unit 150 may include a left delay function, a left amplification function, a left phase processing function, a right delay function, a right amplification function, a right phase processing function, and a D / A conversion function. .

In general, the HRTF adjusts the volume of the direct sound and the indirect sound at the same time. In this embodiment, the indirect sound portion is further processed. In addition, the general HRTF only provides a function of adjusting only the spatial delivery plane sound balance delivered to the ear, whereas the HRTF in the present embodiment is capable of controlling the spatial delivery space position as it operates in the spatial voice position control unit 150. You can adjust the position of the sound source to listen in three dimensions.

The processing relation is (left analog signal) = (processed speech signal) + (processed speech signal) × ((left delay amount) + (left amplification amount) + (left phase throughput)), and (right analog signal) = (Processed speech signal) + (processed speech signal) x ((right delay amount) + (right amplification amount) + (right phase throughput)).

The signal processed by the HRTF is converted into an analog signal while passing through the D / A converter 155.

The main gain amplifying unit 170 controls the volume of the analog signal to be input to the speaker automatically or under the control of the system operating unit 190 according to the request of the listener.

The signal analyzer 160 analyzes frequency components of the noise attenuated speech signal (ie, the processed speech signal) to generate a spectral signal. Based on this spectral signal, the feedback oscillation sound included in the processed speech signal can be searched.

That is, the signal analyzer 160 receives a voice signal (that is, a processed voice signal) that has attenuated the degree of attenuation varying according to the environment or a listening request through the attenuation adjustment selector 140, and processes the received signal. The spectral information is output by analyzing the speech signal for each frequency.

Using the spectrum information analyzed by the signal analyzer 160, the system operator 190 may find a signal source for generating the feedback oscillation sound. The spectral information consists of (spectral signal) = [gN FilterN] _T × (processed speech signal). [gN FilterN] _T is arranged in a parallel structure and analyzes each frequency component to make data and output spectral information.

The system operation unit 190 may control the operations of the above-described units so as to process the noise reduction operation according to a preset program. In other words, each part selects a signal to be mixed and adjusts an amplification gain (or weight) for the selected signal.

In particular, the system operation unit 190 identifies a frequency at which the feedback oscillation sound appears through the spectrum information provided by the signal analyzer 160 and sounds a feedback oscillation sound control command for controlling the feedback oscillation sound of the corresponding frequency. The matching unit 110 is provided. When the sound matching unit 110 receives a control command, the sound matching unit 110 performs a process related to feedback oscillation using a tone and feedback oscillation adjustment function.

In addition, the system operation unit 190 may receive an operation related to noise reduction from a listener. For example, the attenuation control selector 190 may select a signal to be mixed or an operation for adjusting a gain of the selected signal may be received from a listener and applied.

On the other hand, when the user receives a selection to perform the hearing management function and the selection of the reference frequency, the system operation unit 190 controls the signal selection unit 195 to stop the output of the processed voice signal and the hearing management unit ( And outputs the hearing management sound from 200.

The signal selector 195 is mainly disposed at the front end of the main gain amplifier 170 so that one of the auditory management sound from the auditory management unit 200 and the signal from another component (for example, the noise attenuation processing is performed). Voice signal). The operation of the signal selector 195 may be controlled by the system operator 190 or manually by a user.

The noise attenuation apparatus according to the embodiment of the present invention having such a configuration selects only components that require noise attenuation from only one micro-induced mixed signal, and generates various output signals (matching) Weighted mixing of one or more of the signal, the periodic noise attenuation signal, and the level-adapted signal) can provide a sound to the listener. In addition, since it can be converted into three-dimensional sound in the virtual space, even if the listener listens to the sound for a long time is not inconvenient.

Claims (16)

An acoustic range determination unit for determining an ambient sound within a predetermined range from the reference sound when a predetermined reference sound specialized for the subject is set;
An output time determiner configured to determine a sound output time for outputting each of the reference sound and the ambient sound;
An acoustic time matching unit configured to generate sound output control information by matching the output time of each sound with each of the reference sound and the ambient sound;
And an output sound generator configured to generate a hearing management sound to be output to a speaker based on the sound output control information. The method of claim 1,
The frequency of the reference sound and the ambient sound,
An auditory management device characterized in that it is calculated by the formula of {(reference frequency) × 2 ^ (M / L)}.
(Wherein M represents the Mth scale from the reference frequency, and L represents the number of scales to distinguish one octave from the reference frequency) The method of claim 1,
The reference sound and the ambient sound, characterized in that selected based on the scale of the piano, hearing management device. The method of claim 3,
Wherein the ambient sound is selected from the scales in the 1 / K octave range, where K may be one of 1, 2, 1/2, or 1/4, from the reference sound. . The method according to claim 2 or 4,
The sound range determination unit,
The audible acoustic frequency range is divided into a plurality of bands each having a predetermined one octave unit but partially overlapping each other,
And when a specific band including the set reference sound is specified, all or some scales included in the specified band are selected as the peripheral sound. The method of claim 1,
The output time determiner,
A sweep output time for each sound to output each sound in the sweep method of sequentially outputting the reference sound and the ambient sound according to the frequency order;
And a random output time for each sound to be output in a random manner in which the reference sound and the ambient sound are output in a non-sequential manner not in order of frequency. The method of claim 6,
The sound sweep output time is,
Auditory management, characterized in that it is determined in a swept manner to be above a minimum time to recognize the presence of each output sound or below a maximum time to not recognize that each output sound is cut off. Device. The method according to claim 1 or 6,
The auditory management sound is configured to be output according to a method of arbitrarily mixing a sweep method in which the reference sound and the ambient sound are sequentially output in a frequency order and a random method that is not sequentially output in a frequency order. Hearing management device characterized in that. Determining an ambient sound within a predetermined range from the reference sound when a predetermined reference sound specialized for the subject is set;
Determining a sound output time for outputting each of the reference sound and the ambient sound;
Generating sound output control information by matching the tone output time to each of the reference sound and the ambient sound; And
And generating and applying an auditory management sound to be output to a speaker based on the sound output control information to the subject. The method of claim 9,
The reference sound and the ambient sound, characterized in that the selection based on the scale of the piano, hearing management method. The method of claim 9,
The determining of the output time for each sound,
Determining a sweep output time for each sound to output each sound in the sweep method of sequentially outputting the reference sound and the ambient sound according to the frequency order;
And determining a random output time for each sound to output each sound in a non-sequential way of outputting the reference sound and the ambient sound in non-sequential order. The method according to claim 9 or 11,
Generating the hearing management sound,
The auditory management sound is generated such that the reference sound and the ambient sound are output according to a method of arbitrarily mixing a swept method in which the reference sound is sequentially output in a frequency order and a random method that is out of order in the frequency order. How to manage hearing. A device having a hearing management function and attenuating periodic noise from a voice signal by a single microphone:
A periodic sound attenuation control unit for detecting a periodic signal from a signal obtained by digitally converting the voice introduced into the single microphone, and outputting a signal in which the periodic signal is attenuated by mixing an inverted phase of the periodic signal with the digitally converted signal;
An adaptive level range controller for controlling the level of the attenuated signal to output a level-adapted signal;
An attenuation adjustment selection unit for mixing one or all of the signal from which the periodic signal output from the periodic sound attenuation control unit is attenuated and the level-adapted signal output from the adaptive level range control unit to output the processed audio signal;
When a predetermined reference sound specialized for the subject is set, an ambient sound within a predetermined range is determined from the reference sound, a sound output time for outputting the reference sound and each of the ambient sounds is determined, and the reference sound and the ambient sound are determined. An auditory manager configured to generate sound output control information by matching the respective output times with sounds, and to generate a hearing management sound to be output to a speaker based on the sound output control information;
And a signal selector for providing at least one of the processed voice signal or the hearing management sound to a speaker. The method of claim 13,
The periodic sound attenuation control unit is:
A signal block sum processing stage for processing the digitally converted signal into a positive signal;
A signal block sum inverse processing stage for processing the positive signal into an inverse phase that is in antiphase;
The resultant signal is calculated with the positive signal to determine the periodic signal, and to generate arbitrary adaptive Fir Filter coefficients separated by frequency in order to attenuate the determined periodic signal, the coefficients are weighted and applied to the inverse signal. And an adaptive Fir Filter LMS stage for repeating the processing of the attenuated signal of the periodic signal as a resultant signal. The method of claim 13,
A signal analyzer configured to generate spectral information by analyzing frequency components of the processed voice signal to detect a frequency at which a feedback oscillation sound exists from the processed voice signal output from the attenuation control selector; And
And a sound matching unit for analyzing a frequency including feedback oscillation from the spectral information and filtering the analyzed frequency from the digitally converted signal to output a matched signal.
The attenuation control selector,
The noise of the single microphone voice signal with the hearing management function, characterized in that for outputting a signal in which the periodic signal is attenuated, the level-adapted signal, and a mixed signal of at least two of the matched signal; Attenuating device. The method of claim 13,
The hearing management unit,
In the sweep method of sequentially outputting the reference sound and the ambient sound according to the frequency order, a random sweep output time for outputting each sound, and randomly outputting the reference sound and the ambient sound out of order according to the frequency order In this method, the random output time for each note to be outputted is determined.
The auditory management sound is generated by arbitrarily combining the reference sound and the ambient sound by the sweep method according to the sound sweep output time and the random sound output according to the sound random output time. A device for attenuating noise of a single microphone voice signal having a hearing management function.

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