JP2015149550A - microphone correction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce discomfort of voice of the same speaker recorded by different microphones.SOLUTION: A microphone correction device 1 includes a voice input section 30 receiving the sound source inputs from a target microphone MC1 and a converted microphone MC2, a conversion filter creating section 11 for creating a conversion filter by dividing a value, obtained by converting a sound source recorded by the target microphone MC1 into a frequency, by a value, obtained by converting the same sound source as that recorded by the converted microphone MC2 into a frequency, and a conversion filter applying section 12 for applying a conversion filter to a sound source inputted from the converted microphone MC2.

Description

  The present invention relates to a microphone correction apparatus that corrects frequency characteristics between a plurality of microphones.

  Conventionally, as a method for a speaker to use a plurality of types of microphones, for example, a technique in which a digital wireless microphone and an analog wireless microphone are used in combination can be used (see, for example, Patent Document 1).

Japanese Patent No. 5242488

  However, in the method described in Patent Document 1, a digital wireless microphone and an analog wireless microphone can be used together, but correction of characteristics of individual microphones has not been performed. For this reason, when a speaker uses multiple microphones in the same program, the frequency characteristics of the microphones differ despite the same speaker, so the voice quality changes and the viewer feels uncomfortable. there were.

  Therefore, the objective of this invention made | formed in view of this point is providing the microphone correction apparatus which can reduce the discomfort of the audio | voice recorded with the different microphone.

  In order to solve the above-described problems, the microphone correction apparatus according to the present invention includes an input unit that receives a sound source input from each of a target microphone and a conversion target microphone, and a value obtained by converting a sound source recorded by the target microphone into a frequency. Applying the conversion filter to a sound source input from the conversion target microphone, and a conversion filter creation unit that creates a conversion filter by dividing the same sound source recorded by the conversion target microphone with the value converted into a frequency A conversion filter application unit.

  In addition, the sound source recorded by the target microphone and the conversion target microphone can use the voice of the same person.

  According to the microphone correction apparatus according to the present invention, it is possible to reduce a sense of incongruity between sounds recorded by different microphones.

It is a figure which shows schematic structure of the microphone correction apparatus which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The microphone correction apparatus 1 according to the present embodiment can be connected to a target microphone MC1 and a conversion target microphone MC2 that are a plurality of microphones, and corrects the frequency characteristics of the conversion target microphone MC2 to match the frequency characteristics of the target microphone MC1. It is.

  FIG. 1 is a diagram showing a schematic configuration of a microphone correction apparatus according to an embodiment of the present invention. The microphone correction apparatus 1 includes a control unit 10 having a conversion filter creation unit 11 and a conversion filter application unit 12, a storage unit 20 having a frequency conversion data storage unit 21 and a conversion filter storage unit 22, and a voice input unit 30 (input unit). ) And an audio output unit 40, and can be connected to the target microphone MC1 and the conversion target microphone MC2 through the audio input unit 30. Each processing unit 11, 12 of the control unit 10 is configured by a suitable processor, and each processing unit 11, 12 can be implemented by a common processor or can be implemented as an individual processor. The storage unit 20 is a suitable storage device, and may be an external storage device via a communication interface as well as a built-in microphone correction device 1. The audio input unit 30 is a suitable acoustic signal input interface, and accepts sound source input (audio input) from each of the target microphone MC1 and the conversion target microphone MC2, for example, as an audio terminal that can be connected to the target microphone MC1 and the conversion target microphone MC2. The audio output unit 40 is a suitable acoustic signal output interface, and can output the corrected acoustic signal to, for example, a later-stage speaker (not shown).

  The conversion filter creation unit 11 creates a conversion filter that corrects a difference between values obtained by converting the same sound source recorded in the target microphone MC1 and the conversion target microphone MC2 into a frequency, and stores the created conversion filter in the conversion filter storage unit 22. To do.

  When the frequency conversion data storage unit 21 stores a value (frequency conversion data) obtained by converting the same sound source recorded in the target microphone MC1 and the conversion target microphone MC2 into a frequency (frequency conversion data), the conversion filter creation unit 11 sets f to a frequency, Assuming that a value obtained by converting a sound source recorded by the target microphone MC1 into a frequency is X (f), and a value obtained by converting a sound source recorded by the conversion target microphone MC2 into a frequency is Y (f), X (f) / Y (F) Create a conversion filter to be represented.

  In addition, when the value obtained by converting the same sound source recorded in the target microphone MC1 and the conversion target microphone MC2 into a frequency is unknown, the conversion filter creation unit 11 records the same test sound in each of the target microphone MC1 and the conversion target microphone MC2. Create a conversion filter from the sound source data. When the sound source data recorded by the target microphone MC1 is a (t) and the sound source data recorded by the test target microphone MC2 is b (t), the conversion filter creation unit 11 performs sound source data a by Fourier transform. (T) is converted into a value A (f) converted into a frequency, and sound source data b (t) is converted into a value B (f) converted into a frequency, and a conversion filter expressed as A (f) / B (f) is created. To do. At this time, as the test sound, for example, a sound source in which sine waves having various frequencies of 20 Hz to 20 kHz are added can be used. In addition, since the value converted into the frequency obtained by Fourier transform becomes a discrete value, a conversion filter having a continuous value can be obtained by spline interpolation or the like. Moreover, when generating the conversion filter with a plurality of test sounds, the conversion filter creating unit 11 can use the average of the plurality of filters generated for each test sound as the conversion filter. A plurality of test sounds may use different sounds each time, or may use the same sound every time. Note that a voice produced by the same person can be used instead of the test sound.

  Further, when the test sound of the same sound source is used for the target microphone MC1 and the conversion target microphone MC2, recording is performed with the target microphone MC1 and the conversion target microphone MC2 according to the distance between the target microphone MC1 and the conversion target microphone MC2 and the sound source. A time lag and amplitude attenuation occur in the generated sound source. The conversion filter creation unit 11 determines the test sound and the sound source data recorded by each of the target microphone MC1 and the conversion target microphone MC2 from the correspondence relationship between the waveforms of the sound source data recorded by the target microphone MC1 and the conversion target microphone MC2, respectively. The corresponding section can be determined. The conversion filter creation unit 11 can perform a Fourier transform on the sound source data in the corresponding section for each of the target microphone MC1 and the conversion target microphone MC2 to generate a conversion filter. The corresponding section can be obtained by finding a correspondence that maximizes the cross-correlation between the target microphone MC1 and the conversion target microphone MC2.

  The conversion filter application unit 12 applies the conversion filter generated by the conversion filter creation unit 11 to the sound source data input from the conversion target microphone MC2. Note that the conversion filter application unit 12 does not apply the conversion filter generated by the conversion filter creation unit 11 to the sound source data input from the target target microphone MC1. When the conversion filter is R (f), the sound source data from the conversion target microphone MC2 is I (n), and the converted sound source data is O (n), the convolution processing of the conversion filter is expressed by the following equation (1). .

  Here, r (n) is represented by the following formula (2), and w (n) is a window function such as a Hanning window.

  As described above, according to the present embodiment, the conversion filter creating unit 11 converts the value obtained by converting the sound source recorded by the target microphone MC1 into the frequency and the value obtained by converting the same sound source recorded by the conversion target microphone MC2 into the frequency. The conversion filter divided by is created, and the conversion filter application unit 12 applies the conversion filter to the sound source input from the conversion target microphone MC2. As a result, it is possible to reduce the uncomfortable feeling of the sound recorded by different microphones. That is, even if a speaker's voice is recorded with two different microphones, the voice quality can be recorded without changing. For example, in one program, recorded audio and real-time audio such as relay may be mixed, but even if the types of microphones used are different, the microphone correction according to the present invention allows the viewer to It is possible to reduce the sense of discomfort of the voice that is felt. Also, for example, when recording a program, always record the same test sound and then record the program, so even if a new microphone is added, conversion filters can be easily used using past recorded audio. It becomes possible to create.

  In addition, the recording sound sources of the target microphone MC1 and the conversion target microphone MC2 are voices of the same person, so that it is possible to further reduce the sense of discomfort in voice quality when one person uses two microphones. In this case, the same person is desirably the owner of the input voice to which the conversion filter is applied.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each functional unit, each step, etc. can be rearranged so that there is no logical contradiction, and a plurality of functional units, steps, etc. can be combined into one or divided. It is.

DESCRIPTION OF SYMBOLS 1 Microphone correction apparatus 10 Control part 11 Conversion filter production part 12 Conversion filter application part 20 Storage part 21 Frequency conversion data storage part 22 Conversion filter storage part 30 Voice input part (input part)
40 Audio output part MC1 Target microphone MC2 Conversion target microphone

Claims (2)

An input unit for receiving sound source input from each of the target microphone and the conversion target microphone;
A conversion filter creating unit that creates a conversion filter by dividing a value obtained by converting a sound source recorded by the target microphone into a frequency by a value obtained by converting the same sound source as the sound source recorded by the conversion target microphone into a frequency;
A microphone correction apparatus comprising: a conversion filter application unit that applies the conversion filter to a sound source input from the conversion target microphone.   The microphone correction apparatus according to claim 1, wherein the sound source recorded by the target microphone and the conversion target microphone is a voice of the same person.

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