Sound source level calculation device, audio adjustment device, and program

Abstract

To provide a sound source level calculation device capable of reflecting and reproducing physical information such as a sound pressure level lost during recording, and a sound adjustment device and a program capable of adjusting sound data according to the sound pressure level and reproducing the sound data by reproducing an actual sound volume feeling of a sound source.SOLUTION: The sound source level calculation device inputs a sound signal converted from a sound of a sound source object having a sound pressure and a sound pressure level and sound collection information associated with the sound source object, calculates a reproduction sound pressure and a reproduction sound pressure level for reproducing the sound pressure and the sound pressure level of the sound, respectively, on the basis of the sound collection information, and outputs the reproduction sound pressure and the reproduction sound pressure level as sound source level data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an invention relating to a sound source level calculation device, a sound adjustment device, and a program for reproducing the sense of volume of sound actually emitted by a sound source. [Background technology]

[0002] In recent years, object-based audio systems, which allow audio to be customized to suit the viewer's preferences and viewing environment, have been attracting attention. Object-based audio systems are an audio method in which audio signals are controlled by individual audio objects and audio metadata and played back using a renderer. Object-based audio systems have been adopted in movie theaters and home theaters, and efforts are underway to put them to practical use in broadcasting services (Non-Patent Documents 1, 2).

[0003] In conventional channel-based audio, the user listens to the sound mixed by an engineer, but with an object-based audio system, the user can choose to listen to the sound mixed by an engineer or to focus on any sound source object.

[0004] Non-patent documents 3 and 4 propose a series of flows for audio production that can accommodate arbitrary viewpoint video. Non-patent document 5 also reports the implementation of an application that performs interactive playback of video and audio from arbitrary viewpoints, and a demonstration using actual recorded concert audio. Services that provide highly flexible viewing experiences are becoming increasingly important. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Kubo, “Optimization for Constrained Viewing Environments in Broadcasting Services Using Object-Based Audio,” Sound Lectures (Autumn), 1645-1646, 2023. [Non-patent document 2] Sugimoto, “Content Creation for Customizable Broadcasting Services by Combining Object-Based Audio and Multi-Layer Coding,” Sound Lectures (Spring), 653-654, 2024. [Non-patent document 3] Kinoshita et al., “Verification of sound collection system for volumetric audio production,” Sound Lectures (Autumn), 353-354, 2023. [Non-patent document 4] Matsui, “3D binaural rendering for volumetric audio reproduction”, Sound Lectures (Spring), 105-106, 2024. [Non-patent document 5] Tsukada et al., "SDM3602: Free Viewing Point Playback of Interactive 3D Content," Information Processing Society of Japan Transactions on Digital Content, Vol. 6, No. 2, pp. 10-23, Aug. 2018. Summary of the Invention [Problem to be solved by the invention]

[0006] The above-mentioned conventional technology has the problem that channel-based audio cannot emphasize specific sounds to suit the viewer's preferences. For example, when the background sound level is high, dialogue (speech and narration) becomes difficult to hear. Regardless of whether channel-based audio or object-based audio is used, the audio used in content is recorded and edited by an engineer, so the level of each sound source object is adjusted within a certain range. This level is determined not only by the producer's intentions, but also for reasons such as maintaining a signal-to-noise ratio and preventing distortion. It is therefore necessary to adjust the level to a certain extent using microphones and other equipment during the recording stage. In other words, the physical information of the actual sound pressure level of the sound source object is lost during recording.

[0007] In addition, in accordance with the loudness operational regulations, which are standards for controlling the loudness of audio signals in digital television broadcasting, the dynamic range (volume range) is limited to take into consideration the viewing environment. The dynamic range is also limited by the performance of the playback device.

[0008] As mentioned above, due to various factors, only those who listen to the live sound at the venue can experience the actual sound pressure level of the sound emitted from the sound source and the relative levels of each sound source object, and there was a problem in that it was not possible to reproduce the physical information of sound pressure level that was lost during recording.

[0009] The present disclosure has been made in consideration of the above, and aims to provide a sound source level calculation device that can reflect and reproduce physical information, namely sound pressure level, that was lost during recording, and an audio adjustment device and program that can adjust audio data according to the reproduced sound pressure level and reproduce the actual volume of the sound source while playing back the audio data. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, a sound source level calculation device according to the present disclosure inputs an audio signal converted from audio of a sound source object having a sound pressure and a sound pressure level, and sound pickup information associated with the sound source object, calculates a reproduced sound pressure and a reproduced sound pressure level for respectively reproducing the sound pressure and the sound pressure level of the audio based on the sound pickup information, and outputs the reproduced sound pressure and the reproduced sound pressure level as sound source level data.

[0011] The audio adjustment device of the present disclosure is connected to a sound source level calculation device that receives an audio signal converted from the audio of a sound source object having sound pressure and sound pressure level, and sound pickup information associated with the sound source object, calculates a reproduced sound pressure and a reproduced sound pressure level for respectively reproducing the sound pressure and the sound pressure level of the audio based on the sound pickup information, and outputs the reproduced sound pressure and the reproduced sound pressure level as sound source level data, and is capable of receiving the sound source level data, and inputs audio data corresponding to the audio signal, and adjusts the volume of the audio data using the sound source level data. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to reproduce physical information such as sound pressure and sound pressure level that was lost during recording as reproduced sound pressure and reproduced sound pressure level, thereby achieving the effect of being able to reproduce the actual sense of volume of the sound source using the reproduced sound pressure level. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating an example of the configuration of a sound source level calculation device according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of a sound pickup microphone and a microphone referenced by a sound source level calculation device. [Figure 3] FIG. 2 is a conceptual diagram showing a sound collection system for acquiring an audio signal. [Figure 4] FIG. 10 is a flowchart showing the processing of an individual sound source level calculation unit. [Figure 5] FIG. 10 is a diagram illustrating an example of the configuration of a volume control device according to a second embodiment. [Figure 6] FIG. 10 is a flowchart showing the processing of the volume control device. [Figure 7] FIG. 10 is a diagram illustrating an example of the configuration of a sound source level reproducing device according to a third embodiment. [Figure 8] FIG. 2 is a diagram illustrating an example of the hardware configuration of each device or unit according to the first, second, and third embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0014] A sound source level calculation device, a sound adjustment device, and a program according to the embodiments will be described in detail below with reference to the accompanying drawings.

[0015] Embodiment 1 FIG. 1 is a diagram showing an example of the configuration of a sound source level calculation device 10 according to the first embodiment. The sound source level calculation device 10 of this embodiment includes an audio signal level measurement unit 11, a sound pickup information acquisition unit 12, and individual sound source level calculation units (131, 132, 133). n ) and a sound source level data generating unit 14.

[0016] The sound source level calculation device 10 receives as input an audio signal converted from the sound of a sound source object having sound pressure and sound pressure level, and sound collection information associated with the sound source object, calculates a reproduced sound pressure p and a reproduced sound pressure level L for reproducing the sound pressure and sound pressure level of the sound from the audio signal based on the sound collection information, and outputs the reproduced sound pressure p and the reproduced sound pressure level L as sound source level data.

[0017] The audio signal level measuring unit 11 measures the sound pressure signal level V of an audio signal from the audio source data 15. The audio source data 15 includes an audio signal associated with a sound source object and sound source object information indicating what the sound source is.

[0018] The sound source data 15 may be stored in advance in an external storage device (not shown). The external storage device may be, for example, an external hard disk drive, a USB memory, an SD memory, an optical disc drive, an external SSHD, a network storage, or a cloud storage. The audio signal in the sound source data 15 may not be stored in advance in an external storage device, but may be an audio signal output in real time from a preamplifier (described later). The audio signal may be an audio signal output from a sound device such as an audio console (audio mixer) or an audio adjustment console (mixing console) (described later), or may be an audio signal output via a DAW (Digital Audio Workstation). The audio signal and the sound source object information associated with the audio signal may be received by the audio signal level measuring unit 11 from the same external device or from different external devices.

[0019] Regarding the sound source data 15, for example, an audio signal for a sound source object called a jazz drum will be described using FIGS. 2A and 2B. As shown in FIG. 2A, the drums are composed of multiple instruments such as a bass drum, a snare drum, and a cymbal. Seven microphones are arranged corresponding to the multiple component instruments. Seven audio signals are generated via the seven microphones. In this case, one sound source object whose sound source is a jazz drum contains seven audio signals. The sound source object information indicating the type of sound source is stored as "jazz drum." Note that, as shown in FIG. 2A, the sound source object associated with the seven audio signals obtained by each of the seven microphones has audio signals for seven channels.

[0020] The object to be measured by the audio signal level measuring unit 11 may be all sound pressure signal levels V of all audio signals of seven channels as in the example of Fig. 2A, or may be two sound pressure signal levels V of two of the seven channels as in the example of Fig. 2B. Appropriate audio signals required to reproduce the sound pressure and sound pressure level of the audio of the sound source object can be selected arbitrarily or as needed.

[0021] A method for acquiring the audio signal received by the audio signal level measuring unit 11 will be described with reference to FIG.

[0022] The target sound source 30 to be picked up by the microphone 31, i.e., the sound source object, can be anything that emits sound, whether indoors or outdoors. Examples include, but are not limited to, the jazz performance shown in Figures 2A and 2B, as well as musical instrument performances such as orchestral performances, environmental sounds such as wind, waves, rain, and city noise, sound effects for use in television, radio, games, etc., and conversations between people.

[0023] A sound emitted from sound source 30 and having a predetermined sound pressure and sound pressure level is converted into an electrical signal by microphone 31. Here, sound pressure is the variation from the static pressure of a medium caused by sound waves, and is an index of sound intensity. The unit of sound pressure is pascals [Pa]. Sound pressure level is a quantity expressed as the common logarithm of the ratio of the magnitude of sound pressure to a reference value. The unit of sound pressure is decibels [dB]. Although microphone 31 can capture sound by converting the variation in sound pressure into an electrical signal, it is difficult to completely reproduce the physical information, such as the sound pressure and sound pressure level, of the sound actually emitted from sound source 30 in an electrical signal.

[0024] Examples of the microphone 31 include, but are not limited to, a condenser microphone, a dynamic microphone, a ribbon microphone, a pin microphone, a headset microphone, a directional microphone, etc. In addition to external microphones, built-in microphones built into devices such as microphones built into personal computers, voice recorders, mobile terminals, and smartphone microphones are also included. Furthermore, the microphone 31 may be a wired microphone connected to a preamplifier or the like using a cable, or a wireless microphone that communicates wirelessly with a preamplifier or the like.

[0025] The audio signal converted into an electrical signal by the microphone 31 is input to the preamplifier 32 as needed. The preamplifier 32 amplifies the audio signal from the microphone 31 and supplies it at an appropriate level to downstream devices such as an audio console or DAW. The preamplifier 32 can adjust the volume and frequency characteristics of the audio signal. The preamplifier 32 can also have a function to reduce noise from the audio signal.

[0026] The audio signal amplified by the preamplifier 32 is input to an audio device 33, such as an audio console, audio adjustment console, or DAW, as needed. The audio device 33 is used to adjust sound sources not only in music production but also in broadcasting, movies, theaters, events, public facilities, and the like. The audio device 33 has functions such as adjusting the level of the input audio signal, an equalizer that adjusts specific frequency bands of the audio, faders that adjust the volume of each channel, a mute that temporarily silences the audio of a specific channel, and a compressor that adjusts the dynamic range of the audio signal. Other functions of the audio device 33 include a delay that adds a time delay to the audio signal, a reverb that adds a reverberation effect to the audio signal, a noise gate that removes specific noise, panning that adjusts the positioning of the audio signal, a filter that emphasizes or suppresses specific components of the audio signal, mixing that combines multiple audio signals, overdubbing, a pitch shifter that adjusts the pitch of the audio signal, a modulation effect that adds special effects to the audio signal, and a recorder that records and plays back the audio signal.

[0027] In addition, in the sound equipment 33 such as an audio console, an audio adjustment console, a DAW, or the like, nonlinear processing may be performed by a compressor function or the like that adjusts the dynamic range of the audio signal. Therefore, it is basically preferable that the audio signal before being input to the sound equipment 33 is input to the audio signal level measuring unit 11. In addition, when input from the sound equipment 33, it is preferable that the audio signal before being subjected to nonlinear processing such as a compressor is input to the audio signal level measuring unit 11.

[0028] As the audio signal level measuring unit 11, for example, a hardware device such as an audio monitor manufactured by Astro Design, or software such as ProTools manufactured by Avid Technology, can be used.

[0029] The sound pressure signal level V of the audio signal measured by the audio signal level measurement unit 11 can be the peak level (maximum amplitude) of the audio signal or the RMS level, which is an index representing the average power level of the audio signal. The peak level indicates the maximum amplitude of the audio signal and is measured as the instantaneous maximum value of the volume. The RMS level indicates the average power of the audio signal and is measured as the intensity of the sustained volume. When measuring multiple audio signals corresponding to multiple channels, it is preferable that the measured audio signal levels V be unified across all channels at either the peak level or the RMS level.

[0030] Since the measured sound pressure signal level V is likely to vary significantly depending on the measurement timing and sampling interval, the peak level or RMS level can be selected arbitrarily depending on the measurement situation. For example, if the audio signal is recorded from a talk show, the RMS level of the audio signal can be measured for the entire talk show. If the audio signal is recorded from a music program, the audio signal level can be measured using a specific sampling interval during sound check when the program is being played at a flat volume.

[0031] Furthermore, the sound pressure signal level V may be an instantaneous value of the audio signal. For example, the audio signal level measurement unit 11 may be configured as a stream that constantly measures the instantaneous value of the audio signal and constantly outputs the measured audio signal level V.

[0032] Table 1 shows an example of the audio signal level measured by the audio signal level measuring unit 11 expressed in root mean square (RMS) voltage (0 dBv=1 V). In the example of Table 1, the channel numbers correspond to the numbers of the microphones used for sound collection. The audio signal levels of each channel are measured as a unified RMS level.

[0033] [Table 1]

[0034] For channel 1 in Table 1, the RMS audio signal level V is -18.8 [dBv].

[0035] The audio signal level V measured by the audio signal level measuring unit 11 is output to the sound collection information acquiring unit 12. In the example of Table 1, the audio signal levels V for five channels are output.

[0036] The sound collection information acquisition unit 12 receives input of sound collection information including the sound pressure signal level V, and classifies the input information for each channel (each sound source object). In addition to the audio signal level V measured by the audio signal level measurement unit 11, the sound collection information input to the sound collection information acquisition unit 12 includes sound source object information linked to the channel corresponding to the audio signal, microphone information 16 related to the microphone used when generating the audio signal, a preamplifier amplification gain B of the preamplifier used together with the microphone, and other adjustment gains C which are gains related to audio equipment other than the microphone and preamplifier.

[0037] Tables 2 to 4 show examples of the collected sound information input to the collected sound information acquisition unit 12.

[0038] Table 2 shows an example of sound source object information among the sound collection information input to the sound collection information acquisition unit 12. The sound source object information is information that indicates what the sound source is, and is also information for associating the audio signal of the sound source or sound source object with a channel. For example, as shown in Table 2, the sound source object information of channel 1 indicates that it is associated with the audio signal of a sound source object named "vocal," which indicates that the sound is sung by a singer.

[0039] [Table 2]

[0040] Table 3 shows an example of microphone information 16 among the sound collection information input to the sound collection information acquisition unit 12. The microphone information 16 may be stored in an external storage device or may be input by the user. The microphone information 16 is information about the microphone used to acquire the audio signal. The microphone information 16 includes the microphone number m, the type of microphone, the microphone sensitivity α, the microphone body adjustment gain A, the microphone ratio β m Includes:

[0041] [Table 3]

[0042] The microphone number m in Table 3 may be the number of microphones used by the sound source object. For example, for vocals on channel 1, the microphone number is 1. This indicates that one microphone was used for the vocals. For drums on channels 3 and 4, the microphone number for channel 3 is 1 and the microphone number for channel 4 is 2. This indicates that two microphones were used for the drums. Also, since the microphone number is synonymous with the channel number of the sound source object, it may not be an input value but may be obtained from the number of channels of the sound source object.

[0043] The microphone type in Table 3 is the model number of the microphone used when the audio signal was acquired. The microphone type can be input by the user or selected from a drop-down list or pop-up menu.

[0044] The microphone sensitivity a in Table 3 is the sensitivity of the microphone used when the audio signal was acquired. The microphone sensitivity α may use the specification value of the microphone manufacturer used, or a value input by the user. As shown in Table 3, the units of the microphone sensitivity a may not be consistent depending on the microphone manufacturer, such as dB / Pa or mV / Pa, so the sound pickup information acquisition unit 12 may also perform processing to standardize the units for all channels. The microphone sensitivity a can be linked in advance to the type of microphone, and may be automatically input when the type of microphone is input or selected.

[0045] Microphone gain adjustment A indicates the gain adjusted on the microphone side. Microphone gain adjustment A is used to adjust the input sensitivity of the audio signal picked up by the microphone. Table 3 shows that for channels 1 to 4, microphone gain adjustment A is 0. On the other hand, for channel 5, which corresponds to the trumpet, which has a relatively louder volume than the other channels, microphone gain adjustment A is -6. This is because a function called Pad is used, which attenuates the level of the audio signal picked up by the microphone by a certain amount to prevent feedback and other problems.

[0046] Microphone ratio β m is the proportion that each microphone contributes to the level of the sound source object. For example, in the case of drums in Table 3, two channels (two microphones) are assigned, and in order to make the sum of the sounds for a single instrument called drums, which is made up of multiple constituent instruments, equal 1, the sum of channels 3 and 4, which correspond to the single instrument called drums (one sound source object), is set to 1. The microphone ratio may also be set using a percentage. Furthermore, the microphone ratio for each channel may be set arbitrarily depending on the characteristics of each sound source corresponding to the channel.

[0047] Table 4 shows examples of gains of devices connected downstream of the microphone, among the sound pickup information input to the sound pickup information acquisition unit 12. Preamp amplification gain B indicates the gain amplified by the preamp. In the example of Table 4, it is set only for channel 1. Other adjustment gain C indicates the sum of the gains of devices other than the microphone and preamp when gain is controlled by such devices. Devices other than the microphone and preamp include, for example, audio hardware and software such as an audio interface, mixing console, DAW software, power amplifier, digital mixer, and effect processor.

[0048] [Table 4]

[0049] The sound collection information acquisition unit 12 generates sound source-specific sound collection data shown in Table 5 based on the sound collection information shown in Tables 2 to 4. The sound source-specific sound collection data includes, for example, an audio signal level V, a microphone number, a microphone type, a microphone sensitivity a, a microphone body adjustment gain A, a microphone ratio βm, a preamplifier amplification gain B, and an other adjustment gain C for each channel. When there is one target sound source object, the sound collection data includes information for one channel, and when there are multiple target sound source objects, the sound collection data includes information for multiple channels. In the example of Table 5, sound collection data for five channels corresponding to vocals, violin, drums, and trumpet is output. Note that with respect to the other adjustment gain C, + means amplification, and minus means reduction.

[0050] [Table 5]

[0051] The individual sound source level calculation unit 13 receives the sound pickup data generated and output by the sound pickup information acquisition unit 12 for each sound source object, calculates the sound pressure level of the actual sound source and a reproduced audio signal level V' for reproducing the sound pressure from the sound pickup data, and generates a reproduced sound pressure p and a reproduced sound pressure level L as sound source level data based on the reproduced audio signal level V'.

[0052] FIG. 4 is a flowchart illustrating the processing executed by the individual sound source level calculation unit 13 in the first embodiment.

[0053] In step S1, a sound pressure signal level V, a microphone body adjustment gain A, a preamplifier amplification gain B, and other adjustment gain C are obtained from the sound collection data. If there are multiple sound source objects (if there are multiple channels), these parameters are obtained for each sound source object (each channel). For example, if the sound collection information is the example in Table 5, the individual sound source level calculation unit 131 receives the sound collection data associated with a sound source object called vocal (channel 1), and the individual sound source level calculation unit 132 receives the sound collection data associated with a sound source object called violin (channel 2).

[0054] In step S2, a reproduction voltage v is generated to reproduce the sound observed by the microphone. Mic When an actual sound having a predetermined sound pressure and sound pressure level is converted into an electrical signal as an audio signal via the diaphragm of a microphone having a microphone body adjustment gain A, amplified by a preamplifier having a preamplifier amplification gain B, and amplified or attenuated by other equipment having an adjustment gain C, the reproduced audio signal level V' for reproducing the signal level of the audio signal can be expressed by formula (1).

[0055]

number

[0056] Reproduced voltage v Miccan be expressed by Equation (2) using the reproduced audio signal level V' of Equation (1).

[0057]

number

[0058] In step S3, the microphone sensitivity a is obtained from the sound source-specific sound collection data (step S3).

[0059] In step S4, a reproduced sound pressure p and a reproduced sound pressure level L for reproducing the actual sound pressure and sound pressure level of the picked-up sound are calculated. As mentioned above, the microphone sensitivity a may have non-uniform units (dBV / Pa, mV / Pa, etc.), so when the microphone sensitivity a is in dBV / Pa, the reproduced sound pressure p can be expressed by equation (3).

[0060]

number

[0061] On the other hand, when the unit is mV / Pa, the reproduced sound pressure p can be expressed by the following equation (4).

[0062]

number

[0063] Using the relational expression between the sound pressure level L and the sound pressure p, the reproduced sound pressure level L can be expressed by the following equation (5) using the reproduced sound pressure p.

[0064]

number

[0065] In step S5, the maximum microphone number m is calculated from the sound source-specific sound collection data. MAX Get the maximum microphone number m MAXis the maximum value of the input microphone number. For example, in Table 3, if the sound source objects are vocal, violin, and trumpet, the maximum microphone number m MAX On the other hand, if the sound source object is a drum, the maximum microphone number m MAX is 2.

[0066] In step S6, the maximum microphone number m MAX Determine whether the maximum microphone number m is 1. MAX If it is 1 (step S6: YES), the process proceeds to step S9. In the example of Table 3, for the sound source objects that are vocal, violin, and trumpet, the process proceeds to step S9.

[0067] In step S7, the microphone ratio β is calculated from the sound source data. m Here, m is an integer greater than 1. In the example of Table 3, for the sound source object that is a drum, the process proceeds to step S8.

[0068] In step S8, the microphone ratio β m The reproduced sound pressure p and the reproduced sound pressure level L of the sound source are recalculated using the above equation. If the reproduced sound pressure calculated for the i-th microphone in step S4 is pi (i=1,...m), the reproduced sound pressure p of the sound source object is calculated by the microphone ratio β m and the reproduced sound pressure pi, it can be expressed by the following equation (6).

[0069]

number

[0070] Maximum microphone number m MAXWhen is not 1, the reproduced sound pressure level L is calculated using formula (5) from the reproduced sound pressure p calculated using formula (6). In the example of Table 3, the drums have sound collection data related to microphone number 1 and sound collection data related to microphone number 2. The reproduced sound pressure contributed by microphone number 1 is calculated as 0.5p1, and the reproduced sound pressure contributed by microphone number 2 is calculated as 0.5p2. Using formula (6), the reproduced sound pressure p of the sound source object called drums is calculated as 0.5 × (p1 + p2). The reproduced sound pressure level L of the drums is calculated by substituting the calculated reproduced sound pressure p = 0.5 × (p1 + p2) into formula (5).

[0071] In step S9, the calculated reproduced sound pressure level L and reproduced sound pressure p are output as individual sound source levels.

[0072] Table 6 shows examples of sound source levels calculated by the individual sound source level calculation unit 13. For example, the individual sound source level output from the individual sound source level calculation unit 131 is data related to vocals, the individual sound source level output from the individual sound source level calculation unit 132 is data related to violin, the individual sound source level output from the individual sound source level calculation unit 133 is data related to drums, and the individual sound source level output from the individual sound source level calculation unit 134 is data related to trumpet. Note that the individual sound source level calculation unit 131, the individual sound source level calculation unit 132, the individual sound source level calculation unit 133, and the individual sound source level calculation unit 134 may each independently perform the process of FIG. 6 and output the individual sound source levels at their own timing.

[0073] [Table 6]

[0074] The sound source level data generation unit 14 receives the individual sound source levels L calculated by the individual sound source level calculation unit 13, and generates sound source level data for each sound source object. Specifically, the individual sound source level data relating to vocals, violin, drums, and trumpet are compiled as shown in Table 6, and output as sound source level data including the reproduced sound pressure p and the reproduced sound pressure level L for each sound source object.

[0075] As described above, the sound source level calculation device 10 calculates the reproduced sound pressure p and reproduced sound pressure level L that reproduce the sound pressure and sound pressure level of the actual sound emitted from the sound source from the sound collection information, and outputs sound source level data including the reproduced sound pressure and reproduced sound pressure level. It is possible to reproduce the physical information, namely the sound pressure and sound pressure level at the time of sound collection that was lost during recording, as the reproduced sound pressure and reproduced sound pressure level.

[0076] Furthermore, by using the sound source level calculation device 10 according to the first embodiment, the sound source level calculation device 10 can be utilized in the following technical fields and applications. For example, in the broadcasting industry, such as terrestrial digital broadcasting and satellite broadcasting, by reproducing sound pressure information lost during recording, higher quality audio can be provided to viewers and the sense of realism of broadcast content can be improved. In the fields of music production and sound engineering, the sound source level calculation device 10 can be used to accurately reproduce sound pressure information lost during studio recording or live recording, thereby performing optimal mixing and mastering. In the field of film and video production, the sound source level calculation device 10 can be used to reproduce sound pressure levels lost during recording in order to enhance the realism of environmental sounds and sound effects during recording when producing movies and television programs. In the fields of virtual reality (VR) and augmented reality (AR), the sound source level calculation device 10 can be adjusted to reproduce sound pressure information at the time of recording in order to improve the realism of sound effects in VR and AR environments, providing users with a more immersive experience. In the fields of medicine and hearing research, the sound source level calculation device 10 can be used to provide more accurate hearing data by reproducing sound pressure information lost during recording in the development of hearing aids for the hearing impaired and in hearing research. In the field of communications and network technology, it can be used to improve the quality of audio data in audio calls and conference systems by reproducing sound pressure information lost during recording and providing clear, natural audio.

[0077] Embodiment 2 5 is a diagram showing an example of the configuration of a volume control device 20 according to embodiment 2. The volume control device 20 is capable of receiving sound source level data including a reproduced sound pressure p and a reproduced sound pressure level L that reproduce the sound pressure and sound pressure level of actual sound emitted from a sound source, and adjusts the volume of the audio data 27 as content using the audio data 27, a maximum playback volume, and a minimum playback volume.

[0078] The volume control device 20 receives sound source level data. For example, the sound source level data output from the sound source level calculation device 10 of the first embodiment may be used.

[0079] As shown in the example of Table 6, the sound source level data includes sound source object information indicating what the sound source is, and a reproduced sound pressure p and a reproduced sound pressure level L that are associated with the sound source object information and are used to reproduce the sound pressure and sound pressure level of the sound, respectively, from the audio signal of the sound source. For example, the sound source level data may be output directly or indirectly from the sound source level calculation device 10 of the first embodiment, or may be stored in an external storage device.

[0080] Audio data is audio data created as content using the audio source data used to acquire the audio source level data. Audio data created as content refers to audio files that are ultimately delivered to listeners. Examples include music, radio, podcasts, audiobooks, sound effects, and narration. This data is created by artists, producers, engineers, etc., and is completed through a set process including editing, mixing, and mastering.

[0081] The maximum playback volume and the minimum playback volume are the maximum playback volume G set by the user who plays the audio data. MAX and minimum playback volume G MIN is.

[0082] FIG. 6 is a flow chart showing the operation of the volume control device 20. As shown in FIG.

[0083] In step S10, sound source level data is acquired, and the reproduced sound pressures p of all sound source objects are obtained from the sound source level data. For example, in the case of the sound source level data shown in Table 6, four reproduced sound pressures p are acquired for all of vocals, violin, drums, and trumpet.

[0084] In step S11, the maximum value p MAX and the minimum value p MIN and the maximum reproducible sound pressure level (L MAX ) and minimum reproducible sound pressure level (L MINFor example, in the case of the sound source level data shown in Table 6, the maximum value p MAX is 63.2 [Pa] for drums, and the corresponding maximum reproducible sound pressure level (L MAX ) is 130 [dB]. The minimum value p MIN is 0.200 [Pa] for the violin, and the corresponding minimum reproducible sound pressure level (L MIN ) is 80[dB].

[0085] In step S12, the maximum playback volume G MAX and minimum playback volume G MIN Get the maximum playback volume G MAX and minimum playback volume G MIN is a value set by the user. For example, if the volume control device 20 is incorporated as software in a playback device, the maximum playback volume G MAX and minimum playback volume G MIN can be set by the user using the volume adjustment button on the playback device, etc. For example, when a user plays audio data on a smartphone, which is a playback device, and listens to it through earphones, the user can adjust the volume with the earphones connected, setting the minimum playback volume to one tap of the volume button and the maximum playback volume to 12 taps.

[0086] In step S13, a correction coefficient α is calculated. The correction coefficient α is calculated based on the maximum playback volume G MAX and minimum playback volume G MIN and maximum reproducible sound pressure level L MAX and minimum reproducible sound pressure level L MIN It is calculated using equation (7).

[0087]

number

[0088] In formula (7), the maximum playback volume G MAX and minimum playback volume G MIN is taken as the sound pressure level, and the maximum reproducible sound pressure level L obtained in step S11 MAXand minimum reproducible sound pressure level L MIN It is assumed that the volume adjustment is performed linearly using the correction coefficient α. The correction coefficient α is not limited to a predetermined value, and may be expressed as a function depending on the application. In the example of Table 6, the maximum playback volume G MAX 100dB and minimum playback volume G MIN If a requirement of 40 dB is input, the correction factor α=1.2 is obtained.

[0089] In step S14, the sound pressure level of the sound source object is multiplied by the calculated correction coefficient α to calculate the corrected sound pressure level αL. The calculated corrected sound pressure level αL is shown in Table 7. At this stage, only the volume range matches the requirement.

[0090] [Table 7]

[0091] In step S15, the maximum playback volume G MAX or minimum playback volume G MIN Adjust the weighted sound pressure level αL to match the maximum playback volume G MAX When using the maximum playback volume G MAX =αL MAX Therefore, the adjustment value γ is the maximum playback volume G MAX and maximum reproducible sound pressure level L MAX It is calculated using equation (8).

[0092]

number

[0093] The adjustment value γ is added to the corrected sound pressure level αL obtained in step S14. In the example of Table 7, αL MAX is the drum's 156 [dB], and the maximum playback volume G MAXis 100 dB, the adjustment value γ is -56. For the example in Table 7, the adjusted sound pressure level L' is obtained as shown in Table 8 by using the relationship L' = αL + γ. It can be seen that the range (40 [dB] to 100 [dB]) meets the listener's needs while maintaining the actual relative level relationship.

[0094] [Table 8]

[0095] The volume of the audio data is adjusted so that each sound source object is reproduced at the adjusted sound source level calculated in step S15.

[0096] In step S16, the adjusted sound source level is output, and the adjusted sound data is output using the adjusted sound source level.

[0097] In this way, the volume adjustment device 20 calculates the maximum and minimum sound source levels from the sound source level data, and outputs adjusted audio data with the volume adjusted so that the sound is reproduced in accordance with the viewing environment based on the maximum and minimum sound source levels set by the user. When setting the maximum and minimum playback volumes, it is also possible to associate them by setting them using the maximum and minimum levels of the sound source level data. Also, it is possible to enter a background noise level or the like as a sound source object "background sound" in one of the sound source level data, and use that as the L MIN It may also be used as.

[0098] According to the volume adjustment device 20 of the second embodiment, when there is one sound source object, it is possible to reproduce the sense of volume of an actual sound source and play back audio data. For example, when the sound source object is a conversation between one speaker, it is possible to play back audio data with a sense of volume that makes it seem as if that person is actually speaking in front of you. As in the example of Table 8, when there are multiple sound source objects, it is possible to play back audio data with a sense of relative volume that is actually being produced by vocals, violin, drums, and trumpet.

[0099] Furthermore, the volume control device 20 according to the second embodiment can optimize the sense of volume in various fields. It can be used in music production and recording studios to reproduce the relative sense of volume of multiple instruments and vocals and adjust the balance during music production. It can reproduce the sense of volume of each sound source in movies and television programs, achieving a realistic sound. It can be used to adjust and balance the volume in real time during live music performances and events. In virtual reality (VR) and augmented reality (AR), it can reproduce the sense of volume of each sound source in a virtual space as if it were in the real world, allowing users to have a three-dimensional audio experience.

[0100] Embodiment 3 7 is a diagram showing an example of the configuration of a sound source level reproducing device 1 according to embodiment 3. The sound source level reproducing device 1 of embodiment 3 is an integrated device that includes the sound source level calculation device 10 of embodiment 1 as a sound source level calculation unit 2 and the volume adjustment device 20 of embodiment 2 as a volume adjustment unit 3.

[0101] The components of the sound source level calculation unit 2 and the data input and output thereto are the same as those of the sound source level calculation device 10 of embodiment 1, so a detailed description thereof will be omitted. The components of the volume adjustment unit 3 and the data input and output thereto are the same as those of the volume adjustment device 20 of embodiment 2, so a detailed description thereof will be omitted.

[0102] This integration simplifies the overall structure of the device and reduces installation space compared to when the sound source level calculation unit 2 and the volume adjustment unit 3 are installed separately. This allows the sound source level reproduction device 1 to be designed more compactly, making it easier to install and move. It also reduces the number of cables and wires required to connect multiple devices, simplifying wiring work and reducing the risk of noise and loss in signal transmission. Furthermore, integrating the sound source level calculation unit 2 and the volume adjustment unit 3 allows for quick and accurate data communication between these elements. This improves the responsiveness of volume adjustment and enables real-time volume control. In addition, the integration improves overall energy efficiency and reduces power consumption.

[0103] FIG. 8 is a diagram showing an example of hardware for realizing the sound source level calculation device 10 of the first embodiment, the volume control device 20 of the second embodiment, and the sound source level reproduction device 1 according to the third embodiment.

[0104] Each of the devices in the first, second and third embodiments is realized by a computer system including a processing circuit 100 including a processor 102 and a memory 103 , a communication device 101 , an input device 104 and a display device 105 .

[0105] Examples of the processor 102 include a CPU (Central Processing Unit), a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), or a system LSI (Large Scale Integration). Examples of the memory 103 include non-volatile or volatile semiconductor memories such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), and EEPROM (Electrically EPROM), magnetic disks, flexible disks, optical disks, compact disks, minidisks, and DVDs (Digital Versatile Discs).

[0106] This is realized by the processor 102 executing a program for operating as each device or each unit of the first, second, and third embodiments. The program for operating as each device or each unit of the first, second, and third embodiments is stored in advance in the memory 103. The processor 102 reads this program from the memory 103 and executes it to operate as each device or each unit of the first, second, and third embodiments. Furthermore, this program causes a computer to execute the procedure or method of each device or each unit of the first, second, and third embodiments.

[0107] The memory 103 is used to store sound source data, microphone information, sound collection information, audio data, etc. The memory 103 is also used as a temporary memory when the processor 102 executes various processes.

[0108] The input device 104 may be connected to, for example, an external microphone, a keyboard, a mouse, a keypad, or a touch panel.

[0109] The interface device (not shown) is an interface for inputting sound source data, microphone information, sound collection information, audio data, etc. from the outside, and outputting sound source level data, volume-adjusted data, etc. to the outside.

[0110] The display device 105 is a device that displays a screen. The display device 105 is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electro-Luminescence) display. The display device can be omitted as necessary.

[0111] The communication device 101 is a device that enables each device in the first, second, and third embodiments to communicate with an external device wirelessly or via a wire. Note that the communication device 101 can be omitted as necessary.

[0112] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention. [Explanation of symbols]

[0113] 1. Sound source level reproduction device 2 Sound source level calculation section 3 Volume control 5. Sound source data 6. Microphone Information 7. Audio data 10 Sound source level calculation device 11 Audio signal level measurement section 12 Sound collection information acquisition unit 131, 132, 13 n Individual sound source level calculation section 14 Sound source level data generation unit 15 Sound source data 16. Microphone Information 20 Volume adjustment device 27 Audio data 30 sound sources 31. Mike 32 Preamp 33 Sound equipment 100 Processing Circuit 101 Communication equipment 102 processors 103 memory 104 Input Device 105 Display device

Claims

1. An audio signal converted from the sound of a sound source object having a sound pressure and a sound pressure level and sound collection information associated with the sound source object are input; calculating a reproduced sound pressure and a reproduced sound pressure level for reproducing the sound pressure and the sound pressure level of the sound, respectively, based on the sound collection information; outputting the reproduced sound pressure and the reproduced sound pressure level as sound source level data; Sound source level calculation device.

2. 2. The sound source level calculation device according to claim 1, wherein the sound pickup information includes at least one of a microphone sensitivity, a microphone body adjustment gain, a microphone ratio, and a preamplifier amplification gain.

3. an audio signal level measurement unit that measures a sound pressure signal level of the audio signal; a sound collection information acquisition unit that classifies the sound collection information including the sound pressure signal level according to the sound source object; a sound source level calculation unit that generates a reproduced sound pressure signal level for reproducing the sound pressure level of the sound based on the classified sound pickup information, and calculates the reproduced sound pressure and the reproduced sound pressure level based on the generated reproduced sound pressure signal level; a sound source level data generating unit that generates the reproduced sound pressure and the reproduced sound pressure level as the sound source level data; 3. The sound source level calculation device according to claim 1, further comprising:

4. an audio adjusting device connected to a sound source level calculating device that receives an audio signal converted from an audio of a sound source object having a sound pressure and a sound pressure level and sound pickup information associated with the sound source object, calculates a reproduced sound pressure and a reproduced sound pressure level for respectively reproducing the sound pressure and the sound pressure level of the audio based on the sound pickup information, and outputs the reproduced sound pressure and the reproduced sound pressure level as sound source level data, and is capable of receiving the sound source level data; an audio adjusting device that receives audio data corresponding to the audio signal and adjusts the volume of the audio data using the sound source level data;

5. A maximum value and a minimum value are obtained from the reproduced sound pressure; a maximum reproduced sound pressure level and a minimum reproduced sound pressure level corresponding to the maximum value and the minimum value, respectively, are determined from the reproduced sound pressure levels; calculating a correction coefficient from the difference between a predetermined maximum playback volume and a predetermined minimum playback volume and the difference between the maximum playback sound pressure level and the minimum playback sound pressure level; 5. The audio adjusting device according to claim 4, wherein the reproduced sound pressure level of the audio signal is adjusted by multiplying the reproduced sound pressure level by the correction coefficient.

6. calculating an adjustment value based on the predetermined maximum playback volume and the adjusted reproduced sound pressure level; The sound adjusting device according to claim 5, wherein the adjusted reproduced sound pressure level is further adjusted in accordance with the adjustment value.

7. In the computer system, inputting a sound signal converted from the sound of a sound source object having a sound pressure and a sound pressure level, and sound collection information associated with the sound source object; calculating a reproduced sound pressure and a reproduced sound pressure level for reproducing the sound pressure and the sound pressure level of the sound from the sound signal based on the sound pickup information; outputting the reproduced sound pressure and the reproduced sound pressure level as sound source level data; adjusting the volume of audio data using the sound source level data; A program characterized by being executed.

Images