KR101623562B1 - Portable sound amplifier having detachable mic module - Google Patents

Abstract

The present invention relates to a portable sound amplification apparatus comprising a main module and a microphone module that can be separated and connected together. The microphone module includes a remote microphone for receiving a surrounding sound to generate a remote sound signal, and a first radio unit for wirelessly transmitting the remote sound signal. The main module includes a second radio unit for receiving the remote sound signal wirelessly transmitted, a sound processing unit for removing the periodic noise from the remote sound signal to generate a sound signal after processing, a speaker for outputting the sound signal after the processing .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a portable audio amplifying apparatus having a detachable microphone module,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a portable acoustical amplifier capable of being used by a hearing aid, and more particularly to a portable acoustical amplifier having a separate microphone module.

As a conventional art of a portable acoustic amplifying device that can be used by the hearing impaired, Patent No. 10-1099525 (name: portable hearing aid for public places) can be mentioned. 1, a hearing aid is divided into a transmitter and a plurality of receivers, and a plurality of separate hearing aid receiver units are provided to provide a format of a civil application And the hearing aid receiving unit is installed within a radius of 10 m from the receiving unit so that wireless communication is performed between the hearing aid transmitting unit and the receiving unit so that the hearing aid can be carried and used by the hearing aid receiving unit provided on the table.

On the other hand, the portable hearing aid of the related art discloses a configuration in which the transmitter and the receiver wirelessly communicate with each other. However, since the transmitter and receiver operate as separate devices, it is inconvenient for the user to carry each device separately.

That is, the prior art portable hearing aids merely provide a function of wirelessly transmitting the sound to the plurality of reception units wirelessly by the transmitter in accordance with the intention of the transmitter side speaker, You can not use it if you want to.

Patent No. 10-1099525

In order to solve the above problems, it is an object of the present invention to provide a portable sound amplifying apparatus having a detachable microphone module that allows a user with a hearing loss to selectively amplify and listen to a sound of a speaker desired by the user .

According to an aspect of the present invention, there is provided a portable audio amplification apparatus including a separate microphone module, the main module including a main module and a microphone module, Comprising: a remote microphone for receiving a surround sound to produce a remote sound signal; and a first radio for wirelessly transmitting the remote sound signal, wherein the main module comprises: a second A wireless unit, a sound processing unit for removing periodic noise from the remote sound signal to generate a sound signal after processing, and a speaker for outputting the sound signal after the processing.

The microphone module includes a first battery, the main module includes a second battery, and when the microphone module and the main module are coupled to each other, the second battery and the first battery are connected in parallel So that the charge can be distributed.

The first wireless unit of the microphone module is turned off when the first battery and the second battery are connected to each other and is turned on when the first battery and the second battery are separated from each other, Communication with the radio unit can be started.

In addition, the main module may further include a self-microphone for receiving a surrounding sound to generate a self-acoustic signal, and the sound processor may independently control the volume of the remote sound signal and the volume of the self- .

The acoustic processing unit may include a periodic sound attenuating circuit for detecting a periodic noise waveform from an inputted acoustic signal and mixing an opposite phase waveform of the waveform with the acoustic signal to output a periodic noise attenuated decay signal, A sound pressure level correction control circuit for outputting a level adaptation signal by controlling the level of the signal, and a signal synthesis processing circuit for mixing the at least one of the attenuation signal and the level adaptation signal and outputting the mixed signal as an acoustic signal .

The periodic sound attenuation circuit may further include a signal block sum process stage for generating a periodic noise including a periodic noise, a signal block summing process stage for generating an inverse signal that is a reverse phase of the mental arcs, An adaptive Fir Filter LMS stage that weighs the Fir Filter coefficients on the inverse signal and the coefficients produce the attenuation signal by applying a weighted inverse signal to the acoustic signal.

The sound pressure correction circuit may further include frequency-dependent filters for controlling gains of the attenuation signals in order to attenuate the induced noise generated when applying the inverse signal to the acoustic signal, And a gain tilt control unit for controlling a gain of each of the frequency-dependent filters based on the level of the sound wave and the level of the sound wave according to the time of the attenuation signal in order to remove residual image noise remaining in the attenuation signal. Gain Slop Control (GSC).

According to another aspect of the present invention, there is provided a portable acoustic-wave amplification apparatus including a microphone for generating an acoustic signal by receiving ambient sounds, an acoustic sensor for generating periodic noise from the acoustic signal, A processing unit, and a speaker for outputting the processed sound signal as an acoustic signal.

Here, the sound processing unit may include: a periodic sound attenuation circuit for detecting a periodic noise waveform from an inputted sound signal, mixing a negative phase waveform of the waveform with the sound signal, and outputting an attenuated periodic signal whose periodic noise is attenuated; A sound pressure level correction control circuit for controlling the level of the attenuation signal to output a level adaptation signal and a signal synthesis processing circuit for mixing the attenuation signal and the level adaptation signal, .

The apparatus may further include a first wireless unit for wirelessly transmitting the acoustic signal generated by the microphone, and a second wireless unit for wirelessly receiving the acoustic signal in communication with the first wireless unit, And can be remotely separated from the sound processing unit or the speaker.

According to the portable audio amplifying apparatus having the separate microphone module according to the present invention, when the user separates the microphone module from the body module and arranges the microphone module at a desired position, the user can amplify and listen to the sound at a desired position do.

In addition, it is possible to start the operation only by separating the microphone module from the main body module without needing to operate the microphone module separately, which is convenient to use.

In addition, the portable acoustical amplifier according to the present invention can efficiently attenuate periodic noise or howling included in an acoustic signal. The attenuation function is mounted on the main body module, so that the microphone module can be made lighter and smaller.

1 is a block diagram showing the configuration of a portable hearing aid for public places according to the related art.
FIG. 2 is a schematic view illustrating the outline of a portable acoustical amplifier including a separate microphone module according to the present invention. Referring to FIG.
3 is a schematic block diagram for explaining the configuration and operation of a main body module and a microphone module of a portable acoustical amplification apparatus having a detachable microphone module according to the present invention.
4 is a block diagram for explaining the sound processing unit of the main body module in detail.
5 (a) to 5 (j) are views for explaining the detailed configuration of the sound processing unit and the functions of the respective configurations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a portable acoustical amplifier including a separate microphone module according to the present invention will be described with reference to the accompanying drawings. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only and is not intended to be limiting.

2, a mode and a usage of a portable acoustical amplifier including a detachable microphone module according to the present invention will be described. Referring to the drawings, the portable acoustic amplification apparatus according to the present invention includes a body module 20 and a microphone module 10.

The microphone module 10 and the main body module 20 can be coupled or separated from each other by a user. 2 (a) shows a front surface and a top surface of the microphone module and the main body module in a state where they are coupled to each other. FIG. 2 (b) shows a side view of the structure in which the microphone module and the body module are coupled and separated. 2 (c) is a perspective view showing a state in which the microphone module and the main body module are separated.

First, the microphone module 10 can be coupled and fixed to the main body module 20 in various ways. Fig. 2 (b) shows a coupling method of a structure in which an elastic member having projections is provided in the microphone module 10, and the projections are fitted into the grooves of the main body module 20. Fig. When the microphone module 10 is coupled to the main body module 20, the conductive contacts of the two modules can be connected to each other. The contact may be a contact for connecting the battery of the main body module 20 and the battery of the microphone module 10 in parallel to each other, or may be a switch which is turned on or off by connection. The function of this contact point will be described later.

The main body module 20 may be provided with an earphone terminal to which a user's earphone (or speaker) is connected and a microphone (i.e., a self microphone) for receiving sound around the body module. In addition, the main body module 20 is provided with a "power" button for turning on or off the power of the main body module, a "full volume" button for controlling the volume of the sound outputted by the earphone, A "wireless volume" button for controlling the volume of a sound signal (remote sound signal), and a "noise reduction" button for adjusting the degree of attenuation of the periodic noise included in the sound signal.

Furthermore, the main body module 20 may be provided with a plurality of LED or LCD display means for visually displaying the operation state of the main body module itself and the communication state with the microphone module 10. [

The microphone module 10 is provided with a microphone (i.e., a remote microphone) for receiving ambient sound, a "power" button for turning on or off the power of the microphone module itself, A plurality of LEDs or LCD display means for displaying the communication status can be arranged. Further, the microphone module 10 is connected to the main body module 20 and is provided with display means for displaying a state of being charged by the battery of the main body module or charging the battery of the main body module, or a state of being charged by the external power source can do.

The user can normally carry the microphone module 10 in a state in which the microphone module 10 is coupled to the main body module 20 in an integrated state. In a state where the microphone module 10 is coupled to the main body module 20, the microphone module 10 is kept powered off and is only received by the self microphone 242 provided in the main body module 20 And the battery of the main body module 20 and the battery of the microphone module 10 are connected in parallel to each other so that the two batteries share the charge and are charged or discharged or the two batteries are simultaneously charged .

When the microphone module 10 is disconnected from the main body module 20, the microphone module 10 is automatically turned on and the wireless communication between the microphone module 10 and the main body module 20 is mutually connected. The sound from the remote microphone 131 can be wirelessly transmitted to the main body module 20 and the sound from the self microphone 242 and the sound from the remote microphone 131 through the earphone 152 of the main body module 20 Or only one of them can be output.

According to the portable sound amplifying apparatus having the separate microphone module according to the present invention, the user normally carries the microphone module 10 in a state where the microphone module 10 is coupled to the main body module 20, When listening to a TV or watching a conference, only the microphone module 10 is separated and the separated microphone module 10 is placed near the TV or near the presenter of the conference, Not only the sound but also the sound of the desired remote position can be amplified simultaneously (or singly). Also, in some cases, the volume of the sound received at the remote location can be reduced or increased as desired, so that the listener can listen comfortably to the volume of the sound received at the periphery for the listener.

Next, the overall structure and operation of the main body module and the microphone module of the portable acoustic amplification apparatus according to the present invention will be described with reference to the block diagram of FIG.

The microphone module 10 includes a remote microphone 131, a first radio unit 120, a first battery 110, and a first contact 101.

The remote microphone 131 receives the sound around the microphone module to generate an analog sound signal (i.e., a remote sound signal). The generated analog sound signal can be digitally converted and converted into a digital remote sound signal (the operation of converting the analog sound signal to digital can also be performed in the sound processor).

The first radio unit 120 transmits the digital remote sound signal to the second radio unit 220 of the main body module using a predetermined digital radio communication protocol. When the first radio unit 120 receives the power and starts the operation, the first radio unit 120 connects the second radio unit 220 with each other according to a predetermined digital radio communication protocol. This operation is referred to as "pairing ". When mutual communication is connected by pairing, it transmits a remote sound signal and exchanges unique information of the radio part.

The first battery 110 may be configured to supply power to each part constituting the microphone module 10 when the microphone module 10 is detached from the main body module 20. [

The microphone module 10 may be manually turned on or off by a power button as shown in FIG. 2, but is configured to be automatically turned on when detached from the body module and automatically turned off when coupled to the body module .

The first contact 101 is configured to be connected to the second contact 202 of the body module when the microphone module 10 is coupled to the body module 20. [ The first contact 101 may include, for example, a positive terminal and a negative terminal of the first battery 110.

A method of detecting whether the microphone module 10 is detached from the main body module 20 or not may be considered as a method of checking whether the connection of the second battery 210 is detected through the first contact 101. [ On the other hand, a circuit may be constituted so that electromagnetic fluctuations arise in accordance with connection or disconnection between the first contact 101 and the second contact 202, and a sensor for sensing the variation may be added. In addition, a switch of a separate mechanical operating method may be used.

The main body module 20 includes a second radio unit 220, an acoustic processor 230, a speaker 152, a self microphone 242, a second battery 210, a second contact 202).

The second wireless unit 220 performs wireless communication with the first wireless unit 120 of the microphone module according to the digital wireless communication protocol. The second radio unit 220 may be configured to be turned off when the microphone module 10 is coupled and turned on when the microphone module 10 is detached. Alternatively, when the main body module 20 is turned on, the sleep mode is maintained in the state where the microphone module 10 is coupled, or the sleep mode is turned on every predetermined time period to search for the first radio unit 120. [ And may be switched to the normal communication mode when the microphone module 10 is detected to be disconnected or when the first radio unit 120 is searched.

The second wireless unit 220 and the first wireless unit 120 transmit and receive digital information according to a digital wireless communication protocol, so that there is no distortion or omission due to interference. That is, since the digital remote sound signal obtained by digitally converting the analog sound signal by the analog sound wave is transmitted, the sound signal is not distorted. Further, by adding the digital signal encryption processing and the signal omission verification procedure, it becomes possible to guarantee the complete transmission of the acoustic signal.

It is also possible to transmit predetermined control information from the second radio unit 220 to the first radio unit 120. For example, it is possible to provide a function of controlling the operation state (power on / off, remote microphone on / off, sensitivity adjustment, etc.) of the remotely located microphone module 10 by operating the main body module 20 have.

The acoustic processor 230 removes the periodic noise from the acoustic signal generated through the predetermined microphone to generate the acoustic signal (the processed acoustic signal) after the noise attenuation process. After processing, the acoustic signal may be output towards the user via the speaker 152 or earphone.

The sound processing unit 230 detects a waveform of a periodic sound (that is, periodic noise as a noise due to a sound wave periodically generated) from an inputted sound signal, and outputs a reverse phase waveform in which the waveform of the detected periodic sound is inverted And a periodic sound attenuation circuit for mixing the sound signal and outputting the attenuation signal in which the periodic sound is attenuated.

The sound processing unit 230 includes a sound pressure level correction control circuit that controls the level of the attenuation signal generated by the periodic sound attenuation circuit and outputs a level adaptation signal.

In addition, the sound processor 230 may output one of the attenuation signal generated by the periodic sound attenuation circuit and the level adaptation signal generated by the sound pressure volume correction control circuit, or may mix them with each other to generate an after-processing sound signal And a signal synthesis processing circuit.

By effectively removing the periodic noise from the acoustic signal picked up by the microphone by combining various acoustic processing techniques, it is possible to prevent the phenomenon that the periodic noise is amplified and noisy even when the acoustic signal is greatly amplified. In addition, even when there is a large amount of periodic noise in the periphery, the periodic noise can be attenuated and only the non-periodic sound such as speech can be amplified, thereby providing various usability.

Only one self microphone 242 may be installed in the main body module 20 and only one remote microphone 131 may be installed in the microphone module 10. [ However, the sound processing unit 230 of the present invention may provide a function of virtually processing the mono sound received by one microphone into stereo sound and outputting it.

The self microphone 242 receives the sound of the surroundings of the microphone, which is disposed on one side of the main body module 20, and generates an analog sound signal. Further, the own microphone 242 can digitally convert the analog sound signal and output it as a digital sound signal. The digital self acoustic signal will be subjected to noise attenuation and amplification processing by the sound processing unit 230.

The second battery 210 is built in the main body module 20 and supplies power to each part of the main body module. The second battery 210 may be connected in parallel to the first battery 110 by the first contact 101 and the second contact 202. When the first battery 110 is connected to the second battery 210, the charges of both the batteries are distributed to each other. Usually, the second battery is configured to have a larger capacity than the first battery, so that when both batteries are coupled together, the second battery will charge the first battery.

The second contact 202 may be electrically connected in such a manner that the second contact 202 contacts the first contact 101 when the microphone module 10 is coupled to the main body module 20. [ The second contact 202 may include a positive terminal and a negative terminal of the second battery 210.

Meanwhile, in a state where the main body module 20 and the microphone module 10 are separated from each other, the first radio unit 120 and the second radio unit 220 always check the mutual operation state, Is detected to be in the off state, the detected module can automatically switch itself to the power saving mode. In the power saving mode, it is possible to check whether the partner module is turned on every predetermined cycle. If it is detected that the partner module is turned on, it can switch itself back to the normal communication mode.

The sound processing unit of the main body module will be described in detail with reference to the block diagram of FIG. The acoustic processing section includes a microphone input level and signal conversion circuit 231, a characteristic EQ correction and hauling elimination circuit 232, a periodic sound attenuation circuit 233, a sound pressure volume correction control circuit 234, Circuit 235, a signal conversion amplification circuit 236, a signal analysis circuit 237, and a system operation circuit 238. [

The microphone input level and signal conversion circuit 231 matches the level and / or the impedance of the microphone and the sound processing unit 230. Further, it converts the incoming signal Xmic (t), which is an analog sound signal generated by one microphone, into a digital signal Xmin (n).

The characteristic EQ correction and howl removing circuit 232 receives the acoustic signal Xmin (n) generated by the own microphone 242 and digitally converted and the sound signal Xmin (n) transmitted from the microphone module 10 and received by the second radio unit 220 And mixes the remote acoustic signal Xoth (n) to produce a mixed signal Xm (n). It is also possible to use not only the sound signal Xmin (n) and the remote sound signal Xoth (n) but also to adjust the degree of amplification or attenuation of the sound at that frequency by determining whether the listener can hear the sound at that frequency May be further mixed.

The mixed signal Xm (n) is output as a matched signal Xa (n) by adjusting the tone color for each frequency band.

The periodic sound attenuation circuit 233 detects and attenuates only the periodic signal having the periodic waveform pattern in the matched signal Xa (n) output from the characteristic EQ correction and deblocking elimination circuit 232. [ In the present invention, the periodic signal is determined as the periodic noise.

The sound pressure level correction control circuit 234 determines the tone compensation process and the level scale range of the signal provided by the periodic sound attenuation circuit 233, that is, the signal Xsnc (n) in which the periodic signal is attenuated, And outputs a signal Xlsc (n).

First, the preprocessed signal Xsncp (n) is generated by adjusting the pre-processing gain to further filter the periodicity-inducing element in the periodic signal-attenuated signal Xsnc (n).

This preprocessed signal is converted into a signal Xsncb (n) through tone color compensation processing and level adaptive curve control processing for adjusting a level scale range, and this signal is again corrected for the post-processing gain, And becomes the adapted signal Xlsc (n).

The signal synthesis processing circuit 235 outputs the signal E (n) output from the characteristic EQ correction / deblocking elimination circuit 232 and the periodic signal output from the periodic sound attenuation circuit 233 Processed signal Xs (n)) output from the sound pressure level correction control circuit 234 alone or weightedly mixing two or more signals Xsnc (n) .

After processing, the acoustic signal Xs (n) may be output as an acoustic signal through which the periodic noise is removed from the sound received by the microphone, and then output through the speaker 152 as an acoustic signal.

Meanwhile, the acoustic processor 230 according to the present invention may further include a signal conversion amplification circuit that provides a function of converting a mono sound received from a single microphone into a stereo sound in a virtual space.

The use of a single microphone means that only one microphone 242 is provided in the main body module 20 and when the main body module 20 is operated, the sound is received by this single microphone 242 And means to generate a mono acoustic signal. In addition, the microphone module 10 also includes only one remote microphone 131, which means that only one remote microphone 131 receives the sound to generate a mono sound signal.

The signal conversion amplifying circuit 236 generates a spatial sound by arranging the position of the sound source in a virtual space based on the listener using the noise-reduced processed sound signal Xs (n). In the case of an acoustic signal input through one microphone, it can be recognized that the sound source is located between both eyes of the listener. As a result, the listener can feel strabismus and dizziness.

The signal conversion amplifying circuit 236 converts the processed sound signal Xs (n) into an analog sound signal Xsl (n) to be inputted to the left speaker so as to cause the sound source to have the effect that the sound source is arranged in a three- t) and the analog sound signal Xsr (t) to be input to the right speaker. This allows the listener to hear the sound reliably and comfortably.

Further, the signal conversion amplifying circuit 236 can amplify the acoustic signal to be inputted to the speaker 152. [

The signal analysis circuit 237 analyzes each frequency component of the noise-reduced processed sound signal Xs (n) to generate a spectrum signal Xspec (n). Based on this spectrum signal, it becomes possible to search for the feedback oscillation sound included in the processed sound signal Xs (n).

The system operation circuit 238 controls the operation of each circuit constituting the sound processing section 230. The system operation circuit 238 may be software or hardware that incorporates a control algorithm for realizing an optimal noise attenuation process.

The acoustic processing unit 230 according to an embodiment of the present invention selects only components that need noise reduction from only one micro-incoming acoustic signal, and outputs various output signals generated using the selected signals (N), Xsnc (n), and Xlsc (n), by weighted mixing. In addition, since the mono sound can be converted into the three-dimensional sound in the virtual space, it is not inconvenient for the listener to listen to the sound for a long time.

Hereinafter, with reference to Figs. 5 (a) to 5 (j), the detailed configuration of the sound processing unit and functions of the respective configurations will be described.

5 (a) is a diagram for explaining the microphone input level and the signal conversion circuit in more detail. The microphone input level and signal conversion circuit 231 includes an input level matching stage 2312 and an A / D conversion stage 2314.

The input signal Xmic (t) output from the own microphone 242 and input thereto is an analog acoustic signal including not only an aperiodic sound but also a periodic sound recognized as noise.

The input level matching stage 2312 realizes the maximum power transmission of the incoming signal by matching the impedance or level of the microphone with the impedance or level of the subsequent stage, and improves the efficiency of the sound processing.

On the other hand, the A / D conversion stage 2314 converts the incoming signal Xmic (t) into a digital signal Xmin (n).

5 (b) is a diagram for explaining the characteristic EQ correction and howling elimination circuit in more detail. The characteristic EQ correction and howl removing circuit 232 receives the microphone input level and the digital signal Xmin (n) and the remote sound signal Xoth (n) output from the signal conversion circuit 231 and the signal generator 2324, And a signal selection mix and mixer 2322 for selecting and mixing one or more of these signals. In addition, the signal Xm (n) output from the signal selection mix and MUX stage 2322 is converted into the matched signal Xa (n) via the timbre and feedback oscillation adjustment stage 2326. [

Here, the remote sound signal Xoth (n) is different from the signal Xmin (n) output from the self microphone 242 provided in the main body module 20 on which the sound processing unit 230 is mounted, And is obtained by the remote microphone 131 of the module 10 and transmitted wirelessly.

The sound processing unit 230 receives the remote sound signal Xoth (n) and can perform a noise attenuation process together with the signal Xmin (n) by the microphone 242 itself. Thus, the listener can listen to the sound around the main body module 20 carried by him / herself and the sound picked up around the microphone module 10 arranged at the desired position.

The signal generator 2324 controls a signal conversion characteristic and a tone color according to the type of a microphone to preprocess unnecessary sound sources, adjusts feedback induction of the system, and adjusts a specific frequency to adjust the sound to be heard to a desired tone color. And generates an acoustic signal. That is, the signal generator 2324 generates and outputs an adjustment sound having a specific frequency, and the listener can manually adjust the volume of the adjustment sound for the frequency to a desired level, The volume can be adjusted.

The Xm (n) signal output from the signal selection mix and mixer stage 2322 is a single output of Xmin (n), a mixed output of Xmin (n) and Xoth (n) Output.

The single output of Xmin (n) is intended to perform noise reduction processing only on the signal Xmin (n) that has flowed through the self microphone 242 of the main body module and is digitally converted. Mixing and outputting Xmin (n) and Xoth (n) is performed by outputting the digital sound signal Xmin (n) input via the own microphone 242 and the remote sound signal Are mixed together for processing. The single output of the adjustment sound signal of the signal generator 2324 is selected when the listener wishes to adjust the sound to be heard through the speaker 152 according to his /

The function and operation of the tone and feedback oscillation adjustment stage 2326 will be described with reference to Fig. 5 (c). The tone color and feedback oscillation adjustment stage 2326 is composed of a plurality of stages of filters (Filter1, Filter2, Filter3, ..., FilterN). The multi-stage filters are arranged for tuning the tone of the desired frequency and controlling the frequency at which the feedback oscillation occurs in order to control the tone of the desired frequency and to remove unnecessary sound sources. The matched signal Xa (n) is expressed as {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 can be adjusted by a control command (a control command that commands to control the feedback oscillation sound of a specific frequency) provided by the system operation circuit 238. [

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

5 (d) is a diagram for explaining the periodic sound attenuation circuit in more detail. The periodic sound attenuation circuit 233 outputs a matched signal Xa (n) whose tone color is controlled through the characteristic EQ correction and the howling elimination circuit 232 and whose pre-processing for eliminating unnecessary sound sources is performed and the generation of the feedback oscillation is controlled, As input. Then, a noise-attenuated signal Xsnc (n) obtained by attenuating only the periodic signal among the signal components constituting the matched signal Xa (n) is output.

The periodic sound attenuation circuit 233 includes a signal block sum processing stage 2332, a signal block sum processing stage 2334, and an adaptive Fir filter LMS stage 2336. LMS means Least Mean Square (LMS) processing.

The Fir Filter LMS stage 2336 is shown in more detail in FIG. 5 (e). The Fir Filter LMS stage 2336 obtains an active coefficient, which is a result weight according to the LMS process, and performs signal processing to apply it to the Fir Filter coefficient to be adapted. The adaptive Fir filter coefficients are controlled by the active coefficients, which are the result weights according to the LMS process, and the T _period and G _weights can be provided from the system operation circuit 238 or self generated at the Fir Filter LMS stage 2336. Thereby, the signal block sum process 2332 of the periodic sound attenuation circuit 233, the signal block sum inverse process 2334, and the adaptive Fir filter LMS 2336 are cyclically processed. The adaptive Fir Filter LMS stage 2336 generates an error signal Xerr (n), which is modified and iterated until the error signal Xerr (n) becomes zero.

The Fir filter generates a tap delay and applies the weights W ₀ (n) to W _m (n) to each tap and then determines the periodic signal (or the error signal Xerr (n)) in the LMS result . The noise is attenuated by adjusting the active coefficient repeatedly until the periodic signal becomes zero.

The fact that the periodic signal is zero means that the periodic noise is mostly attenuated.

In processing the matched signal Xa (n) output from the characteristic EQ correction and deblocking elimination circuit 232, the periodic sound attenuation circuit 233 includes a signal block sum process stage 2332 and a signal block sum process stage 2332. [ (N)) can be generated by combining the signal processing paths constituted by the adaptive FIR filter LMS stage 2334 and the adaptive Fir Filter LMS stage 2336, and output the noise-attenuated signal Xsnc (n).

The upper block and the lower block of Fig. 5 (d) show that the stages are combined in different ways. In addition to these combinations, they may be implemented in any other order.

The signal block sum processing stage 2332 compares the error signal Xerr (n) with the period noise reduction signal Xsnc (n) for the purpose of signal processing the block unit notation (Xas (n) )). ≪ / RTI >

The signal block summation processing unit 2334 reflects the LMS activity coefficient according to the error signal Xerr (n) for the purpose of signal processing the block unit inverse signal X'as (n) for periodic signal recognition To perform signal processing.

As a result, when the error signal Xerr (n) approaches zero by performing active signal processing on the minuscule Xas (n) and the inverse signal X'as (n), the noise- The signal Xsnc (n) is generated.

The reason for using the FIR filter in the present invention is to maintain the linear phase of the signal to be subjected to the noise reduction processing and since the Fir filter has a linearity, the periodic signal can be linearly removed when the opposite phase of the periodic signal is mixed .

The noise reduction signal (Xsnc (n)) is a signal having passed through the Filter Fir that _{X'as (n) × W m (} n), Xsnc (n) = Σ W m (n) × X'as (nm ).

The periodic sound attenuation circuit 233 is for applying the adaptive Fir Filter coefficient W _m (n) to the signal X'as (n) by using the active algorithm, It has the purpose of minimizing.

Here, Xerr (n) = Xas (n) + Xsnc (n) when referring to the upper block in Fig. 5 (d) (N) = Xa (n), where Hs (n) is the transfer function of the signal block sum processing stage 2332 and Hsin (n) is the transfer function of the signal block sum inverse processing stage 2334, X Hs (n), and similarly, X'as (n) = Xa (n) H's (n).

Finally, Xerr (n) = Xas (n) + Xsnc (n), and taking the mean square root of the active algorithm, is summarized as follows.

Xerr (n) = 2 Xerr (n) x (dXerr (n) / dW (n))

= 2 Xerr (n) × d {Xas (n) + (X'as (n) × [W m (n)] T)} / dW (n)

That is, Xas (n) and X'as (n) from each other is because the signals in reverse phase relations, [W _m (n)] according to the active factor, such as a vector table _T [W _m (n)] of the cyclic mutual offset _T When processing is performed, Xerr (n) will be close to 0, and finally Xsnc (n) will be able to reproduce only an aperiodic signal.

On the other hand, it is usually possible to remove periodic signals with only the LMS active algorithm. However, it is necessary to judge to what degree the signal is to be viewed as a periodic signal and to judge to what extent the determined periodic signal should be canceled.

This determination is based on the T (period) and G (weight), which are applied to the signal block sum processing stage 2332, the signal block sum processing stage 2334, and the adaptive Fir Filter LMS stage 2336, Lt; / RTI >

If the degree of cancellation of the periodic signal from the acoustic signal is increased, the induced noise causing the afterimage effect is rather increased. Therefore, in order to solve such a side effect, a sound pressure volume correction control circuit 234 is applied.

5 (f) is a diagram showing a specific configuration of the sound pressure volume correction control circuit. When the sound signal passes through the periodic sound attenuation circuit 233, the attenuated signal Xsnc (n) around the periodic component is output. The sound pressure level correction control circuit 234 remains in the signal Xsnc (n) The induced noise portion of the signal is processed.

The sound pressure volume correction control circuit 234 includes a pre-processing gain stage Pre G, a level control curve control stage 2342, and a post-processing gain stage Post G. The pre-processing gain stage and post-processing gain stage are applied to level the signal. Level adaptive curve control stage 2342 is applied to process at least a portion of the induced noise portion, which is described in more detail in Figure 5 (g).

The level adaptive curve control stage as shown in the upper block of FIG. 5 (g) is connected to the cascade-connected multistage filters Filter1, Filter2, and Filter3 in order to attenuate the unintentionally added induced noise by processing in the periodic sound attenuation circuit. Filter2 ... FilterN) and a gain slope control (GSC).

The noise attenuated signal Xsnc (n) is passed through the sound pressure level correction control circuit 234 to control the level of the frequency band in which the volume control, the afterimage noise control and the induced noise appear, n)). The signal Xlsc (n) is processed as follows. Gn FilterN] is for controlling the level of the frequency band in which the induced noise appears, and may be a notch filter, a chef filter, a peak filter, or the like. .

In the gain gradient control stage (GSC), the residual-image noise control process is performed by controlling the distortion of the sound wave according to Attack, Release, Sustain, Decay Time and the gain slope according to the volume.

The lower block of FIG. 5 (g) shows an example of controlling the level in the gain slope control (GSC). In the figure, the horizontal axis represents the input value of the signal, and the vertical axis represents the output value of the signal. In the drawing, a straight line having a constant slope represents a reference line in which a ratio of input to output of the signal linearly increases. At this time, in the system operation circuit 238, arbitrarily, for some input values, the gain can be controlled in such a way as to raise the gain above the reference line and the other part lower than the reference. Thus, the residual image noise control processing can be performed.

5 (h) is a diagram for explaining the signal synthesis processing circuit in more detail. The signal synthesis processing circuit 235 generates a signal Xa (n) (matching signal) in which a tone color-controlled and unnecessary sound source (i.e., feedback oscillation) is eliminated through the characteristic EQ correction and the howling elimination circuit 232, (Noise reduction signal) XSnc (n) processed by the periodic component through the attenuation circuit 233 and the sound pressure level control circuit 234 to control the volume control, the residual image noise control, and the induced noise frequency band And an input terminal for receiving a signal Xlsc (n) (level-adapted signal), respectively, and one or a plurality of the signals are selected to finally output the processed sound signal Xs (n).

G1, G2 and G3 for adjusting the gain of each of the input signals and switches (sw1, sw2 and sw3) for selecting the signal input are arranged at the input terminals of the signal synthesis processing circuit 235 . The signals selected by the switches are mixed at the mix stage 2352 and output.

The post-processing acoustic signal Xs (n), which is a mixed signal selected by the amplification stages G1, G2, G3 and the switches sw1, sw2, sw3, is expressed as follows. Xs (n) = (G1 占 sw1 占 Xlsc (n)) + (G2 占 sw2 占 Xsnc (n)) + (G3 占 sw3 占 Xa (n)). The gain of the amplification stage can be adjusted according to the desired degree of noise attenuation.

Conventional sound processing apparatuses only fix the amplification gain of a signal and merely turn it on / off. Therefore, it is difficult to adapt to the environmental change of the surroundings and it is difficult to respond to the request of the listener.

However, the sound processing unit 230 according to the present invention may be configured to variously select a signal using the amplification stages G1, G2, and G3 of the signal synthesis processing circuit and the switches sw1, sw2, and sw3, It is possible to effectively respond to the surrounding environment or the listening request.

As an example of the control operation, when the noise attenuation degree is Off, only the matched signal Xa (n) can be output by setting only Xs (n) = (G3 x sw3 Xa (n)). At this output, the tone and the feedback oscillation can be audible controlled.

When the degree of attenuation is ON, Xs (n) = (G1 x sw1 x Xlsc (n)) + (G2 x sw2 x Xsnc (n)) + (G3 x sw3 x Xa G1 = 0, G2 = α, G3 = β are applied, sw1 can be Off, sw2 and sw3 can be On or Off. Thus, the noise-attenuated signal Xsnc (n) is mixed with the level-adapted signal Xlsc (n) after the noise attenuation and is output. In this output, the timbre and feedback oscillation are controlled, the periodic noise is attenuated, and the level-adjusted sound can be heard.

On the other hand, in the case of listening to a sensitive sound by accepting the noise of the original sound to some extent, it is also possible to mix and listen a part of the signals for which the noise has not been removed by setting G1 to 0, which is a little weighting value, .

5 (i) is a diagram for explaining the signal conversion amplification circuit in more detail. The signal conversion amplifying circuit 236 performs spatial control on the post-processing acoustic signal Xs (n) outputted through the signal synthesizing processing circuit 235, and generates a spatial sense which is recognized from the sound heard through the speaker, It is possible to eliminate a phenomenon in which the visual sense perceived by the user, that is, a phenomenon in which the sound image and the visual image overlap each other. This reduces the visual fatigue of the listener and prevents the pain and dizziness of the ears and the head from occurring even when listening to the sound for a long time.

In this way, the signal conversion amplifying circuit 236, which performs the function of converting the mono sound inputted by only one microphone into the stereo sound in the space, processes the signal by using the principle of HRTF (Head Related Transfer Function) . The signal amplification circuit 236 includes a left delay stage L delay, a left amplification stage Lg, a left phase processing stage L phase, a right delay stage R delay, a right amplification stage Rg, A phase processing stage (R phase), and a D / A converter 2364.

In general, the HRTF adjusts the volume of the direct sound and the indirect sound simultaneously. In this embodiment, the indirect sound portion is additionally processed. In addition, the general HRTF provides only the function of adjusting the spatial transmission plane sound balance to be delivered to the ear, whereas the HRTF in this embodiment operates in the signal conversion amplification circuit 236 to enable the spatial transmission space position control The position of the sound source to be heard can be three-dimensionally adjusted.

The processing relation is Xsl (n) = Xs (n) + Xs (n) × L Delay (n) + Lg + L Phase (R Delay (n) + Rg + R Phase (n)).

The HRTF processed signals Xsl (n) and Xsr (n) are converted into analog signals Xsl (t) and Xsr (t) through the D / A converter 155. The signal Xsl (t) may be input to the left speaker, and the signal Xsr (t) may be input to the right speaker.

The signal conversion amplifying circuit 236 outputs the analog signals Xsl (t) and Xsr (t) to be inputted to the speaker 152 automatically or under the control of the system operation circuit 238, .

5 (j) is a diagram for explaining the signal analysis circuit in more detail. The signal analyzing circuit 237 receives the signal Xs (n) processed with the degree of attenuation with respect to the noise variably in accordance with the environment or the listening request through the signal synthesis processing circuit 235, ), And outputs spectral information (Xspec (n)).

The system operating circuit 238 can use the information (Xspec (n)) analyzed by the spectrum analyzing circuit 237 to find a signal source for generating a feedback oscillation sound. The spectral information is composed of (Xspec (n)) = [gN FilterN] _T x Xs (n). [gN FilterN] _T is arranged in a parallel structure, and each frequency component is analyzed and data is outputted to output spectral information.

The system operation circuit 238 can control the operation of each section described above so as to process the noise reduction operation in accordance with a preset program. That is, the signal to be mixed is selected in each unit and the amplification gain (or weight) of the selected signal is adjusted.

Particularly, the system operation circuit 238 identifies the frequency at which the feedback oscillation sound appears through the spectrum information provided by the signal analysis circuit 237, and outputs a feedback oscillation sound control command for controlling the feedback oscillation sound of the frequency EQ correction and howl removing circuit 232. [ The characteristic EQ correction and howl removing circuit 232 receives the control command and performs the processing relating to the feedback oscillation using the tone color and feedback oscillation adjustment stage 2326. [

Also, the system operation circuit 238 may receive an operation related to noise attenuation from the listener. For example, the signal synthesis processing circuit 235 can select a signal to be mixed and an operation for adjusting a gain for the selected signal from the listener.

According to the portable audio amplifying apparatus having the separate microphone module according to the present invention having the above-described structure, it is possible to obtain a sound similar to the sound heard in the actual space when listening through the earphones of both ears, . Furthermore, periodic noise is minimized so that only necessary sounds can be selected and heard.

Also, the main body module and the microphone module are combined into one portable sound amplifying device, and the user can carry only one device. And when you want to hear the sound far from the current position, you can use the microphone module separately.

In addition, when the main body module and the microphone module are combined, it is possible to simultaneously charge them using one charger. In a state where the body module and the microphone module are coupled, the battery is connected in parallel so that the use time of the device is prolonged. When each module is used separately and then joined again, It is possible to always maintain an optimal remaining battery level.

Also, when one of the modules is turned off while the main body module and the microphone module are separated from each other, the other module automatically switches to the power saving mode, thereby improving battery utilization efficiency.

In addition, the main body module has a function of adjusting the overall volume and a function of individually controlling the volume by the microphone module, thereby minimizing inconvenience caused by the sound being large or small.

The embodiments of the present invention described above are merely illustrative of the technical idea of the present invention, and the scope of protection of the present invention should be interpreted according to the claims. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the essential characteristics thereof, It is to be understood that the invention is not limited thereto.

Claims (10)

A portable acoustic amplifying apparatus comprising a main module and a microphone module that can be carried with each other separated and combined,
The microphone module comprises:
A remote microphone for receiving a surrounding sound to generate a remote sound signal,
And a first radio section for wirelessly transmitting the remote sound signal,
The main module comprises:
A second radio unit for receiving the remote sound signal wirelessly transmitted,
A sound processor for removing periodic noise from the remote sound signal to generate a sound signal after processing,
And a speaker for acoustically outputting the processed acoustic signal,
The sound processing unit includes:
A periodic sound attenuation circuit for detecting a periodic noise including periodic noise from an input sound signal and mixing an inverse signal that is a reverse phase of the psychoaccept with the sound signal to output a periodic noise attenuated decay signal,
A frequency filter for frequency-dependent gain control of the attenuation signal, a multi-stage filter for equalizing the frequency-dependent filters for controlling the frequency-dependent gain of the attenuation signal, A sound pressure level correction control circuit having a gain slope control (GSC) for controlling the attenuation signal and outputting a level adaptation signal;
And a signal synthesis processing circuit for outputting the level adaptive signal or the mixed signal of the attenuation signal and the level adaptive signal as an acoustic signal after processing. The method according to claim 1,
Wherein the microphone module comprises a first battery,
Wherein the main module comprises a second battery,
Wherein when the microphone module and the main module are coupled to each other, the second battery and the first battery are connected in parallel to distribute charge. 3. The method of claim 2,
The first radio unit of the microphone module is turned off when the first battery and the second battery are connected to each other and is turned on when the first battery and the second battery are separated from each other, And a communication unit for communicating with the portable audio amplifier. The method according to claim 1,
The main module includes:
Further comprising a self-microphone for generating a self-acoustic signal by receiving ambient sound,
Wherein the sound processing unit is capable of independently controlling the volume of the remote sound signal and the volume of the self sound signal. delete The method according to claim 1,
Wherein the periodic sound attenuation circuit comprises:
A signal block sum processing stage for generating the above-
A signal block summation block for generating the inverse signal,
And an adaptive Fir Filter LMS stage for weighting the adaptive Fir Filter coefficients separated for each frequency on the inverse signal and applying the weighted inverse signal to the acoustic signal to generate the attenuation signal. Wherein the portable audio amplifying device includes a removable microphone module. delete A microphone for generating an acoustic signal by receiving ambient sound,
An acoustic processor for removing periodic noise from the acoustic signal to generate an acoustic signal after processing,
And a speaker for acoustically outputting the processed acoustic signal,
The sound processing unit includes:
A periodic sound attenuation circuit for detecting a periodic noise including periodic noise from an input sound signal and mixing an inverse signal that is a reverse phase of the psychoaccept with the sound signal to output a periodic noise attenuated decay signal,
A frequency filter for frequency-dependent gain control of the attenuation signal, a multi-stage filter for equalizing the frequency-dependent filters for controlling the frequency-dependent gain of the attenuation signal, A sound pressure level correction control circuit having a gain slope control (GSC) for controlling the attenuation signal and outputting a level adaptation signal,
Further comprising a signal synthesis processing circuit for outputting the level adaptation signal or a mixed signal of the attenuation signal and the level adaptation signal as an acoustic signal after processing. delete 9. The method of claim 8,
A first wireless unit for wirelessly transmitting the acoustic signal generated by the microphone;
Further comprising: a second radio unit for communicating with the first radio unit to wirelessly receive the sound signal,
And to separate the microphone remotely from the sound processing unit or the speaker.

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