System for modifying environmental sound into comfortable sound

Abstract

To reduce discomfort to noise included in environmental sound.SOLUTION: When noise included in inputted environmental sound cannot be selected, an outputted comfortable sound source becomes complicated. When normal noise and steady noise simultaneously occur, only normal noise with a large peak may be converted and steady noise may not be converted. When all the inputted environmental sounds are converted, sound which is not noise is converted, the number of converted sounds becomes large, a complex sound source is created and sounds become unpleasant. Thus, by adding two divisions of conversion processing (S30 to S34 and S40 to S44) and determination processing of converted sound (S30 and S40), unnecessary sound is not converted while corresponding to steady noise. Thus, discomfort can more effectively be reduced by not only reducing discomfort of steady noise such as engine sound from a heavy machine but also selecting noise to be converted to noise with the large peak.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an environmental sound comfort system that makes environmental sounds comfortable. [Background technology]

[0002] Noise is generally recognized as undesirable, and various noise control technologies have been known in the past. For example, Patent Document 1 discloses a system that uses a sound sensor such as a microphone to measure noise generated and propagated within the construction machinery itself during operation, and if the actual noise measurement value is greater than an allowable value, notifies the operator of this by sounding an alarm from a speaker in the driver's seat of the construction machinery. Furthermore, Patent Document 2 discloses an air conditioning noise comfort device that estimates the frequency spectrum of air conditioning noise based on the air flow conditions of the air conditioning unit, selects an appropriate masking sound, and outputs it from an audio device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-126387 [Patent Document 2] Japanese Patent Application Publication No. 2018-122677 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 allows the operator who receives the report to operate the system to keep noise levels below the allowable level, which is thought to reduce the impact of construction noise on nearby areas. Also, the technology described in Patent Document 2 superimposes a masking sound on the air conditioning noise, which is thought to make the air conditioning noise less audible.

[0005] However, all of these prior art technologies are measures aimed at suppressing noise (making noise less loud or harder to hear), and do not change the unfavorable image of noise, so noise can still be a major source of stress for people. In contrast, if some method could improve the image of noise even slightly, it would be expected that people would feel less stressed than before even when they hear noise, and it could be possible to reduce the annoyance felt by noise contained in environmental sounds.

[0006] Therefore, an object of the present invention is to provide a technology that can reduce the discomfort caused by noise contained in environmental sounds. [Means for solving the problem]

[0007] The present invention employs the following solutions to solve the above-mentioned problems. Note that the solutions and the wording in parentheses below are merely examples, and the present invention is not limited thereto. The present invention can be an invention that includes at least one of the invention-specifying matters shown in the solutions below. Furthermore, each invention-specifying matter shown in the solutions below can be made into a subordinate concept by adding an element that limits the invention-specifying matter, or can be made into a superordinate concept by removing an element that limits the invention-specifying matter.

[0008] Solution 1: The environmental sound comfort system of this solution is an environmental sound comfort system that includes an input unit to which noise is input, a determination unit that determines whether the noise input to the input unit is a first noise or a second noise based on the frequency of the noise, a conversion unit that converts the first noise into a spectrum and converts it into a first comfort sound source based on the spectrum, and converts the second noise into a spectrum and converts it into a second comfort sound source based on the spectrum, and an output unit that outputs the first comfort sound source and the second comfort sound source.

[0009] According to this solution, noise can be divided into two types of noise and converted into a comfort sound source, so that discomfort caused by noise contained in environmental sounds can be further reduced.

[0010] Solution 2: The environmental sound comfort system of this solution is an environmental sound comfort system that is any of the solutions described above, characterized in that the conversion unit converts the first noise or the second noise that exceeds a predetermined noise level into the first comfort sound source or the second comfort sound source.

[0011] According to this solution, only noises exceeding a predetermined noise level are converted into comfort sound sources, so that it is possible to select which noises are converted.

[0012] Solution 3: The environmental sound comfort system of this solution is any of the solutions described above, characterized in that the predetermined noise level is a different value for the first noise and the second noise.

[0013] According to this solution, the predetermined noise level of the first noise can be made different from the predetermined noise level of the second noise, and therefore the noises to be selected can be made different between the first noise and the second noise.

[0014] Solution 4: The environmental sound comfort system of this solution is an environmental sound comfort system in which, in any of the solutions described above, the conversion unit converts the first noise into the first comfort sound source with a high pitch, and converts the second noise into the second comfort sound source with a low pitch that is lower in sound than the first comfort sound source.

[0015] According to this solution, a first comfort sound source of high tones and a second comfort sound source of low tones are employed, and by separating the roles of the two types of comfort sound sources, it is possible to further reduce the discomfort caused by noise contained in environmental sounds.

[0016] Solution 5: The environmental sound comfort system of this solution is an environmental sound comfort system that, in any of the solutions described above, is characterized in that the conversion unit converts the first noise into the first comfort sound source of a melody sound, and converts the second noise into the second comfort sound source of a bass sound.

[0017] According to this solution, a first comfort sound source of melody sounds and a second comfort sound source of bass sounds are adopted, and by separating the roles of the two types of comfort sound sources, the discomfort caused by noise contained in environmental sounds can be further reduced.

[0018] Solution 6: The environmental sound comfort system of this solution is any of the solutions described above, characterized in that the conversion unit converts the first noise into the first comfort sound source which is a short sound, and converts the second noise into the second comfort sound source which is a long sound that is longer in duration than the first comfort sound source.

[0019] According to this solution, a first comfort sound source of short sounds and a second comfort sound source of long sounds are adopted, and by dividing the roles of the two types of comfort sound sources, it is possible to further reduce the discomfort caused by noise contained in environmental sounds. [Effects of the Invention]

[0020] According to the present invention, it is possible to reduce discomfort caused by noise contained in environmental sounds. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a block diagram showing the configuration of an environmental sound comfort system 10 according to an embodiment. [Figure 2] FIG. 2 is a diagram showing waveforms of normal noise and stationary noise. [Figure 3] FIG. 1 is a conceptual diagram showing the range of noise conversion. [Figure 4] FIG. 10 is a diagram illustrating an example of selecting noises to be converted. [Figure 5]10 is a flowchart showing an example of the procedure of processing executed by the environmental sound comfort system 10. [Figure 6] 10A to 10C are sequential diagrams showing an example of information input made by a user through operations on the feature information input unit 13. [Figure 7] FIG. 1 is a diagram showing an example of application of the environmental sound comfort system 10 to digital signage. DETAILED DESCRIPTION OF THE INVENTION

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiment is a preferred example of an environmental sound comfort system, and the present invention is not limited to this example.

[0023] FIG. 1 is a block diagram showing the configuration of an environmental sound comfort system 10 according to an embodiment. The environmental sound comfort system 10 is a system that processes environmental sounds, particularly noise, and creates and outputs a comfortable sound source (e.g., music) that makes the most of the noise while making it comfortable. The environmental sound comfort system 10 is composed of a computer that is equipped with the programs and software required for system processing, and various devices connected to the computer. The environmental sound comfort system 10 can be a system constructed using a computer that has the following functional units:

[0024] The environmental sound comfort system 10 can be implemented in digital signage, a dedicated PC (personal computer), a dedicated terminal, etc. The environmental sound comfort system 10 includes an input unit 11, a determination unit 12, a feature information input unit 13, a conversion unit 14 (sound comfort circuit), and an output unit 15.

[0025] The input unit 11 is a part to which noises (first noise, second noise) included in the environmental sound are input. The input unit 11 includes, for example, a sound collection microphone. The sound collection microphone is a device that collects noises included in the environmental sound outdoors (near a construction site). The sound collection microphone is, for example, a directional microphone, an omnidirectional microphone, an all-weather microphone, etc.

[0026] The determination unit 12 is a part that determines whether the noise included in the environmental sound input to the input unit 11 is a normal noise (first noise) or a steady noise (second noise) based on the frequency of the noise.

[0027] The characteristic information input unit 13 is a device (for example, a touch panel) that has both a display function and an input function. The characteristic information input unit 13 receives input of characteristic information regarding the characteristics of the first comfort sound source and the second comfort sound source in response to an operation by a user of the environmental sound comfort system 10.

[0028] The input of the feature information may be input by direct operation to the feature information input unit 13, or may be input by indirect operation from outside using a smartphone, etc. The input of the feature information may be input for changing only the first comfort sound source, may be input for changing only the second comfort sound source, or may be input for changing both the first comfort sound source and the second comfort sound source.

[0029] The conversion unit 14 converts normal noise into a spectrum and converts it into a first comfort sound source based on the spectrum, and also converts steady noise into a spectrum and converts it into a second comfort sound source based on the spectrum. Specifically, the conversion unit 14 converts normal noise collected by the input unit 11 into a spectrum and converts the spectrum into MIDI data (digital data) in MIDI (Musical Instrument Digital Interface) format for the first comfort sound source, which indicates the aspects of each of its components. The conversion unit 14 also converts steady noise collected by the input unit 11 into a spectrum and converts the spectrum into MIDI data for the second comfort sound source, which indicates the aspects of each of its components. The reason for converting into MIDI data is that the signal waveform corresponding to noise is difficult to process because the composition of the noise cannot be grasped in its original state.

[0030] The conversion unit 14 also converts the MIDI data into a first comfortable sound source and a second comfortable sound source based on the feature information received by the feature information input unit 13. Furthermore, the conversion unit 14 converts the sound data corresponding to the first comfortable sound source and the second comfortable sound source into an audio signal.

[0031] The output unit 15 is a part that outputs the first comfort sound source and the second comfort sound source. The output unit 15 includes, for example, a speaker. The speaker is a directional speaker, an omnidirectional speaker, or the like. The output unit 15 outputs the first comfort sound source and the second comfort sound source according to the audio signal converted by the conversion unit 14.

[0032] Data, setting values, etc. handled by each functional unit and circuit of the environmental sound comfort system 10 are stored in a memory unit (not shown) as necessary. The computer that constitutes the environmental sound comfort system 10 is a general-purpose computer (e.g., a PC, cloud server, smartphone, tablet terminal, etc.) equipped with a CPU, RAM, HDD, various I / Fs, etc., and by implementing programs, etc. in the computer, the CPU of the computer functions as each functional unit and each circuit. Note that instead of such a configuration, a computer dedicated to the environmental sound comfort system 10 may be designed, and physical circuit boards corresponding to each functional unit and each circuit may be provided on that computer, either integrally or separately.

[0033] In addition, at least one of the input unit 11, judgment unit 12, feature information input unit 13, conversion unit 14, and output unit 15 may be connected to a computer via a network or cable, or at least one of these functions may be connected to a second computer separate from the first computer in which the program etc. is implemented, and the first computer and the second computer may be connected via a network etc.

[0034] Figure 2 shows the waveforms of normal noise and steady noise. The vertical axis in the figure shows the noise level (sound pressure level) [dBA], and the horizontal axis shows time [s]. Figure 3 is a conceptual diagram showing the range of noise conversion. In a situation where both normal noise and steady noise are occurring, if only the maximum input sound pressure level is converted into a comfort sound source, steady noise that has a low sound pressure level but is harsh to the ears will be difficult to convert.

[0035] Therefore, in this embodiment, steady noise S2, which is mainly generated as low-frequency sound, is also converted into a comfort sound source. That is, in this embodiment, instead of converting noise across the entire frequency range all at once as shown in Fig. 3(A), the conversion process is branched into two, as shown in Fig. 3(B), and the low-frequency steady noise S2 and the high-frequency normal noise S1 are converted separately. Furthermore, the frequency width W1 of the normal noise S1 can be selected arbitrarily, and the frequency width W2 of the steady noise S2 can also be selected arbitrarily. Note that normal noise refers to construction noise that occurs unexpectedly at demolition sites, etc., and steady noise refers to engine noise that occurs steadily due to the use of heavy machinery, etc.

[0036] Figure 4 shows an example of selecting noises to be converted. As shown in Figure 4(A), if all input noises (noises in range A1) were converted into MIDI data, the number of sounds to be output would be too large. Therefore, in this embodiment, as shown in Figure 4(B), selection is performed during conversion for both normal noises (noises in range A2) and steady noises (noises in range A3). This makes it possible to select noises to be converted and narrow down the number of sounds to be output.

[0037] Figure 4 shows an image of the converted MIDI data using a user interface similar to that of general MIDI editing software. The bands of various lengths shown in the figure correspond to each component of the spectrum. The vertical position of the band indicates the pitch (sound height) of each component, and the corresponding notes are represented using piano keys. The length of the band indicates the duration of each component (sound duration). Note that the density of the band may also indicate the sound pressure (sound intensity) of each component.

[0038] In this embodiment, the first and second pleasant sound sources are created by adding characteristic information about the characteristics of the music input by the user to such MIDI data. Note that such MIDI data information can also be displayed to the user.

[0039] 5 is a flowchart showing an example of the procedure of the process executed by the environmental sound comfort system 10. The example of the procedure will be explained below.

[0040] Step S10: An input process of noise included in the environmental sound is executed. In this process, the input unit 11 (a sound collection microphone or the like) collects the noise, converts it into an electrical signal, and outputs it. The output electrical signal is sent to the determination unit 12 directly or via a file.

[0041] Step S20: A process for branching between normal noise and stationary noise is executed. In this process, the determination unit 12 determines whether the noise input to the input unit 11 is normal noise (first noise) or stationary noise (second noise) based on the frequency of the noise.

[0042] For example, the determination unit 12 can determine that noise with a frequency of about 250 to 4 kHz is normal noise, and that noise with a frequency of about 63 to 250 Hz is steady noise. Note that noise at 250 Hz may be determined to be normal noise or steady noise. The frequency that is the boundary between normal noise and steady noise can be changed arbitrarily. Furthermore, the lower limit of steady noise and the upper limit of normal noise can also be changed arbitrarily.

[0043] If the noise is determined to be normal noise, the noise conversion flow for normal noise in steps S30 to S34 is executed, and if the noise is determined to be stationary noise, the noise conversion flow for stationary noise in steps S40 to S44 is executed.

[0044] [Noise conversion flow for normal noise] Step S30: A conversion sound determination process is executed. In this process, the conversion unit 14 determines whether the normal noise exceeds the first conversion determination line L1 (predetermined noise level) (whether the noise level of the noise is greater than the numerical value of the line in FIG. 2). The conversion unit 14 converts the normal noise determined to exceed the first conversion determination line L1 (see FIG. 2) into a first comfort sound source in the subsequent process.

[0045] Step S31: A process of converting into MIDI data is executed. In this process, the conversion unit 14 converts the electrical signal of normal noise determined in step S30 to exceed the first conversion determination line L1 into a frequency spectrum using a Fourier transform or the like, analyzes the frequency spectrum of the normal noise, extracts each component of the spectrum, and converts it into MIDI data for a first sound-enhancing sound source that indicates the aspect of each component of the spectrum (pitch, sound pressure, sound duration, etc.). The sound conversion process is performed by the conversion unit 14 using software installed in a computer. The software may be independently developed and installed, or an existing DAW (Digital Audio Workstation) or other software may be used.

[0046] Step S32: The scale reflection process is executed. In this process, the conversion unit 14 checks whether the selection of the scale (bright, dark, calm, etc.) has been changed by the user's operation, and executes the scale update process if the selection of the scale has been changed, but does not execute the scale update process if the selection of the scale has not been changed. When executing the scale update process, the conversion unit 14 updates the scale settings stored in the storage unit with the scale selected by the user's operation.

[0047] In the scale reflection process, the conversion unit 14 reflects the scale setting in the MIDI data for the first comfortable sound source. For example, if the user selects [Dark Feeling 2] from among multiple options for the scale, the conversion unit 14 changes the scale of the music to be created to a scale (e.g., D minor) corresponding to [Dark Feeling 2]. On the other hand, if the scale selection has not been changed, the conversion unit 14 maintains the scale of the music to be created as the scale (e.g., C major) that was initially set in advance.

[0048] Step S33: A tone color reflection process is executed. In this process, the conversion unit 14 checks whether the tone color (type of instrument) selection has been changed by the user's operation, and executes a tone color update process if the tone color selection has been changed, but does not execute a tone color update process if the tone color selection has not been changed. When executing a tone color update process, the conversion unit 14 updates the tone color settings stored in the storage unit with the tone color selected by the user's operation.

[0049] In the tone color reflection process, the conversion unit 14 reflects the tone color setting in the MIDI data for the first comfortable sound source. For example, if the user selects "Guitar" from among multiple tone color options, the conversion unit 14 changes the tone color of the music to be created to the tone color of the guitar. On the other hand, if the tone color selection has not been changed, the conversion unit 14 maintains the tone color of the music to be created as the initial tone color (for example, the tone color of a violin) that was initially set.

[0050] Step S34: A quantization reflection process is executed. In this process, the conversion unit 14 checks whether the selected rhythm (fine (fast), normal, coarse (slow), etc.) has been changed by the user's operation, and executes a rhythm update process if the selected rhythm has been changed, but does not execute the rhythm update process if the selected rhythm has not been changed. When executing the rhythm update process, the conversion unit 14 updates the rhythm settings stored in the storage unit with the rhythm selected by the user's operation.

[0051] In the quantization reflection process, the conversion unit 14 reflects the rhythm setting in the MIDI data for the first comfortable sound source and then performs quantization. For example, if a user selects [Slightly Fine 1] from among multiple rhythm options, the conversion unit 14 changes the rhythm of the music to be created to a rhythm corresponding to [Slightly Fine 1] (e.g., a rhythm composed mainly of eighth notes). On the other hand, if the selected rhythm has not been changed, the conversion unit 14 maintains the rhythm of the music to be created as the previously initialized rhythm (e.g., a rhythm composed mainly of quarter notes). Then, the conversion unit 14 performs quantization to align the timing of the sounds of each component to the set rhythm. Then, by executing steps S32 to S34, MIDI data for the first pleasant sound source is generated.

[0052] Note that the processing of steps S32 to S34 can be performed in any order. In other words, the above example procedure is merely an example and is not limited to this. For example, the execution order of the procedure related to the scale (step S32), the procedure related to the timbre (step S33), and the procedure related to quantization (step S34) is not limited to the above order. For example, the procedure related to the timbre may be executed before the procedures related to the scale and quantization. Also, in the above example procedure, information related to the scale, timbre, and rhythm is input through operations on the feature information input unit 13, but further information related to musical features (e.g., tempo, etc.) may also be input. Furthermore, in the above example procedure, initial values ​​are set in advance for the scale, timbre, and rhythm. However, instead of this, for example, initial values ​​may be set only for the timbre, or initial values ​​may be set arbitrarily for all items.

[0053] [Noise conversion flow of steady noise] The noise conversion flow for stationary noise is basically the same as the noise conversion flow for normal noise, except that the data handled is data for stationary noise. Therefore, overlapping explanations will be omitted where appropriate.

[0054] Step S40: A conversion sound determination process is executed. In this process, the conversion unit 14 determines whether the stationary noise exceeds the second conversion determination line L2 (predetermined noise level). The conversion unit 14 converts the stationary noise determined to exceed the second conversion determination line L2 (see FIG. 2) into a second comfort sound source in the subsequent process.

[0055] Here, the first conversion decision line L1 and the second conversion decision line L2 are set to different values ​​for normal noise and stationary noise (see FIG. 2). Specifically, the first conversion decision line L1 is set to a higher value than the second conversion decision line L2. The first conversion decision line L1 can be set so that it intersects with the waveform of normal noise. This prevents all sounds from being converted for normal noise. On the other hand, the second conversion decision line L2 can be set so that it does not intersect with the waveform of stationary noise and is positioned below the waveform of stationary noise. This allows all sounds for stationary noise to be converted. However, the second conversion decision line L2 may also be set so that it intersects with the waveform of stationary noise.

[0056] Step S41: A process of converting into MIDI data is executed. In this process, the conversion unit 14 converts the electrical signal of the steady noise that was determined in step S40 to exceed the second conversion determination line L2 into a frequency spectrum by Fourier transform or the like, analyzes the frequency spectrum of the steady noise, extracts each component of the spectrum, and converts it into MIDI data for a second sound-enhancing sound source that indicates the aspect of each component of the spectrum (pitch, sound pressure, sound duration, etc.).

[0057] Step S42: A process of reflecting the musical scale is executed. In the process of reflecting the musical scale, the conversion unit 14 reflects the musical scale setting in the MIDI data for the second comfortable sound source. Step S43: A tone color reflecting process is executed. In the tone color reflecting process, the conversion unit 14 reflects the tone color setting in the MIDI data for the second comfortable sound source. Step S44: Quantize Reflection Processing is Executed In the quantize reflection processing, the conversion unit 14 reflects the rhythm setting in the MIDI data for the second comfortable sound source, and then executes quantization. Then, by executing steps S42 to S44, MIDI data for the second pleasant sound source is generated. Note that the processing of steps S42 to S44 can be performed in any order.

[0058] Step S50: The rhythmic sound addition process is executed. In this process, the conversion unit 14 checks whether the rhythmic sound addition has been changed by a user operation, and executes the rhythmic sound addition process if the rhythmic sound addition has been changed, but does not execute the rhythmic sound addition process if the rhythmic sound addition has not been changed. When executing the rhythmic sound addition process, the conversion unit 14 updates the rhythmic sound addition setting stored in the storage unit with the rhythmic sound addition selected by the user operation. In this process, the conversion unit 14 also checks whether the user operation has selected to turn off the rhythmic sound, and executes the rhythmic sound OFF process if the rhythmic sound OFF is selected, but can also not execute the rhythmic sound OFF process if the rhythmic sound OFF is not selected. When executing the rhythmic sound OFF process, the conversion unit 14 enables the rhythmic sound OFF setting stored in the storage unit, which results in a state where the rhythmic sound is not output.

[0059] Furthermore, the conversion unit 14 reflects the setting of adding rhythm sounds in the MIDI data for the first and second amenable sound sources. For example, if the user selects "drums" from among multiple options for rhythm sounds, the conversion unit 14 adds drum sounds to the music to be created. On the other hand, if the selection of rhythm sounds has not been changed, the conversion unit 14 maintains the rhythm sounds of the music to be created as initially set (for example, no rhythm sounds, electronic rhythm sounds added, etc.).

[0060] By performing such processing, the conversion unit 14 can create a first pleasant-sound source based on normal noise, taking into account information input by a user of the environmental sound comfort system 10 through operation of the feature information input unit 13. The conversion unit 14 can also create a second pleasant-sound source based on steady noise, taking into account information input by a user of the environmental sound comfort system 10 through operation of the feature information input unit 13.

[0061] Furthermore, the conversion unit 14 can convert normal noise into a first comfort sound source with a high pitch (see range A2 in FIG. 4, a sound range around C5), and can convert steady noise into a second comfort sound source with a low pitch (see range A3 in FIG. 4, a sound range around C3) that is lower in pitch than the first comfort sound source.

[0062] Furthermore, the conversion unit 14 can convert normal noise into a first comfort sound source of a melody sound (see range A2 in FIG. 4, a sound with musical content), and can convert steady noise into a second comfort sound source of a base sound (see range A3 in FIG. 4, a sound that forms the basis of the melody sound).

[0063] Furthermore, the conversion unit 14 can convert normal noise into a first comfort sound source that is a short sound (see range A2 in FIG. 4, a sound that continues for less than a predetermined time), and can convert steady noise into a second comfort sound source that is a long sound that is longer than the first comfort sound source (see range A3 in FIG. 4, a sound that continues for more than a predetermined time).

[0064] Step S60: Sound source output processing is executed. In this processing, the conversion unit 14 converts the MIDI data corresponding to the first pleasant sound source and the second pleasant sound source into audio signals, and outputs them at a timing after a predetermined time (for example, 30 ms to 3 s) has elapsed since the noise contained in the environmental sound was input (noise was collected) in step S10. The output audio signals are transmitted to the output unit 15 directly or via a file. Then, the output unit 15 immediately outputs the transmitted audio signals. As a result, the first pleasant sound source and the second pleasant sound source are output from the output unit 15.

[0065] In the environmental sound comfort system 10, the first and second comfortable sound sources are created based on noise in the above-described manner from start to finish, and an audio signal is output at a timing after a predetermined time has elapsed since the noise was input (i.e., since the user heard the noise), thereby outputting the first and second comfortable sound sources (i.e., the user hears the first and second comfortable sound sources).

[0066] The reason for deliberately delaying the output of the audio signal (music that has been made pleasant) is based on the description in the paper "Experiments and Considerations on the Perception of Delay in a Performance System with Delay" (by Nishibori Yu et al., Information Processing Society of Japan Research Report, vol. 2003, no. 127 (2003-MUS-053), pp. 37-42, December 21, 2003). This paper presents experimental results that show that if a delay of 30 ms or more is introduced into a piece of music, the sound is perceived as being delayed. Based on the results of this experiment, by deliberately delaying the output of the audio signal and outputting it at a timing after a predetermined time has passed since the noise contained in the environmental sound was input, it is possible to make the listener perceive that the first and second pleasant-sound-enhanced sound sources are delayed from the noise, that is, that the noise and the first and second pleasant-sound-enhanced sound sources are out of sync (the noise and the first and second pleasant-sound-enhanced sound sources are not the same thing), and it is possible to make the first and second pleasant-sound-enhanced sound sources easier to hear.

[0067] Note that the above procedure example is merely an example and is not limited to this. For example, in the above procedure example, the conversion unit 14 delays the output of the audio signal. Alternatively, the conversion unit 14 may output the audio signal immediately and the output unit 15 may delay the output of the audio signal. Alternatively, the processing of any step may be delayed so that the timing of finally outputting the audio signal is after a predetermined time has elapsed since the noise was collected. In either case, the user can hear the first and second comfortable sound sources, which have been made comfortable based on the noise, at a timing after a predetermined time has elapsed since the user heard the noise. Note that the environmental sound comfort system 10 may output the first and second comfortable sound sources without waiting for the predetermined time to elapse.

[0068] FIG. 6 is a sequence of diagrams showing an example of information input by a user through operations on the characteristic information input unit 13. In FIG.

[0069] In Figure 6 (A): The screen of the feature information input unit 13 displays three items as an environmental sound pleasantness menu: tone selection, scale selection, and rhythm selection. Note that, although not specifically shown, rhythm selection also includes rhythm sound selection. The user can access the screen of the touched item by touching any of the items. Furthermore, when the environmental sound pleasantness system 10 is started, initial settings are applied to each of these three menus, and the output unit 15 outputs a first pleasant sound source M1 in which normal noise is pleasantly sounded using the initially set tone, scale, and rhythm, and a second pleasant sound source M2 in which steady noise is pleasantly sounded. Here, it is assumed that the user touches [Tone selection].

[0070] In FIG. 6 (B): When the user touches [Select tone], the screen of the feature information input unit 13 displays a display related to tone selection. Specifically, the default instrument (violin) is displayed as the current tone at the top of the screen. Below that, multiple instrument options are displayed, with the instrument corresponding to the current tone surrounded by a bold frame. The user can check the instrument options by swiping the screen, and can change the tone to another instrument by touching that instrument. At this point, the output unit 15 still outputs the first pleasant-sound sound source M1, in which normal noise has been made pleasant using the default tone (violin), scale, and rhythm, and the second pleasant-sound sound source M2, in which steady noise has been made pleasant. Now, let's assume that the user touches [Trumpet].

[0071] In FIG. 6 (C): When the user touches [Trumpet], the screen of the feature information input unit 13 displays a message indicating that the selection of the timbre has been changed. Specifically, the most recently selected [Trumpet] is displayed at the top of the screen as the current timbre, and the most recently selected [Trumpet] from among multiple instrument options is displayed surrounded by a bold frame. In this way, the user can change the selection of the timbre with an intuitive and easy operation. At this point, the output unit 15 outputs the changed timbre (trumpet), a first pleasant-sound sound source M3 in which normal noise has been made pleasant using the initially set scale and rhythm, and a second pleasant-sound sound source M4 in which steady noise has been made pleasant.

[0072] By touching the "Back" button displayed on the screen, the user can return to the environmental sound improvement menu shown in (A) of Figure 6, and from there proceed to other items (scale selection, rhythm selection). We will not explain the contents of the screens related to other items here, but just like the screen related to tone selection described above, the screen is designed to allow users to change their selections with intuitive and easy operations even if they do not have specialized knowledge of music.

[0073] In the example shown in Figure 6(A), three selection items (tone, scale, rhythm) are displayed as the environmental sound pleasantness menu, but the menu is not limited to these and more selection items (for example, tempo, etc.) may be displayed. In the examples shown in Figures 6(B) and 6(C), only single instruments are displayed as options, but it is also possible to display a combination of multiple instruments as a single option, such as a band arrangement (for example, a combination of guitar, bass, and drums) or a string arrangement (for example, a combination of violin, viola, cello, and double bass). When such an option is selected, the noise is converted into a composite tone that combines multiple instruments and is made pleasant.

[0074] 6 shows an example in which only a display for selecting the characteristics of the music is displayed on the screen of the characteristic information input unit 13, but in addition to this display, other information related to the environmental sound comfort menu, such as displaying waveforms before and after noise comfort is achieved (at least one waveform such as the waveform of normal noise, the waveform of steady noise, the waveform of the first comfort-enhancing sound source, or the waveform of the second comfort-enhancing sound source), may be displayed on the same screen or separately on a different screen. Also, a questionnaire may be conducted on the screen of the characteristic information input unit 13 (including questions about the user's age and gender, questions about satisfaction with the comfort-enhancing sound source, etc.), and data including the questionnaire results may be sent to an external server, and the sent data may be stored on the external server.

[0075] 7 is a diagram showing an example of application of the environmental sound comfort system 10 to digital signage. Here, an example is shown in which the environmental sound comfort system 10 is applied to a digital signage DS installed at a construction site.

[0076] Figure 7 (A): shows a digital signage DS installed on a temporary fence TF at a construction site, with an output unit 15 installed in a position close to the digital signage DS (for example, above the digital signage DS). The screen of the digital signage DS displays greetings for passersby and the name of the construction company, along with images of the surrounding scenery and workers. Passersby can access the main menu by touching the "Touch Here" button displayed on the screen, for example, and can access various content that can be displayed on the digital signage DS by touching an item displayed on the main menu.

[0077] One of the contents that can be displayed on the digital signage DS is the "Noise Improvement Menu." The Noise Improvement Menu corresponds to the Environmental Sound Improvement Menu shown in Figure 6, but because the environmental sounds generated at construction sites are mainly construction noise, it can also be expressed directly as the "Noise Improvement Menu." Here, we assume that a passerby touches the "Touch Here" button, and then touches the "Noise Improvement Menu" on the main menu.

[0078] In Figure 8 (B): When a passerby touches the [Noise Comfort Menu], content using the environmental sound comfort system 10 is displayed on the screen of the digital signage DS. Specifically, the right side of the screen (corresponding to the characteristic information input unit 13) displays content similar to the environmental sound comfort menu shown in Figure 6 (A), but because the users here are passersby, the menu uses more familiar expressions so that any passerby will feel comfortable trying it out.

[0079] Furthermore, the output unit 15 outputs a first pleasant-sound sound source M1 and a second pleasant-sound sound source M2 in which noise has been made pleasant using the initially set timbre, scale, and rhythm. The waveform of the original noise and the waveforms of the first pleasant-sound sound source and the second pleasant-sound sound source in which the noise has been made pleasant are displayed side by side on the left side of the screen. Note that the waveform shapes are merely examples. Passersby can experience turning noise into music with their own hands by freely operating the menu displayed on the right side of the screen.

[0080] Conventional digital signage installed at construction sites displays information such as the details of the work being carried out that day, renderings and photos of the completed project, and weather forecasts, but it lacks content and is not something that would make passersby want to stop and take a look.

[0081] In contrast, the Digital Signage DS, which applies the Environmental Sound Comfort System 10, allows passersby to easily operate the noise comfort menu displayed on the screen and have fun experiencing how noise changes into music when the tone, scale, rhythm, etc. are changed. By providing such content via the Digital Signage DS, it is possible to improve the image people have of noise.

[0082] The environmental sound comfort system 10 may also be applied to digital signage installed in locations other than construction sites. For example, the environmental sound comfort system 10 may be applied to digital signage installed in airports, train stations, etc., and a first and second comfortable sound source that have been made comfortable based on the noise generated in these locations may be output as background music. Alternatively, the environmental sound comfort system 10 may be applied to digital signage installed near highways, railroad tracks, etc., and a first and second comfortable sound source that have been made comfortable based on the noise generated in these locations may be output as new environmental sounds. The environmental sound comfort system 10 may also be applied to devices and systems other than digital signage.

[0083] As described above, this embodiment has the following advantages. (1) According to this embodiment, the noise contained in the environmental sound can be divided into normal noise and steady noise (two types of environmental sound) and converted into a comfort sound source. Therefore, by harmonizing the two types of comfort sound sources, the discomfort caused by the noise contained in the environmental sound can be further reduced.

[0084] (2) According to this embodiment, only noises that exceed the first conversion judgment line L1 (predetermined noise level) or the second conversion judgment line L2 (predetermined noise level) are converted into comfort sound sources, so it is possible to select the noises to be converted.

[0085] (3) According to this embodiment, the first conversion judgment line L1 (predetermined noise level of the first noise) and the second conversion judgment line L2 (predetermined noise level of the second noise) can be made different, so that the noise to be selected can be made different between normal noise and steady noise.

[0086] (4) According to this embodiment, the first comfort sound source of high tones and the second comfort sound source of low tones are employed, and the roles of the two types of comfort sound sources are divided, thereby further reducing the discomfort caused by noise contained in environmental sounds. In particular, the first comfort sound source of high tones is generated intermittently, and the second comfort sound source of low tones is generated constantly, so that the continuity of the comfort sound sources can be maintained while also improving musicality.

[0087] (5) According to this embodiment, the first comfort sound source of melody sounds and the second comfort sound source of bass sounds are employed, and the roles of the two types of comfort sound sources are divided, thereby further reducing the discomfort caused by noise contained in environmental sounds. In particular, the first comfort sound source of melody sounds is generated intermittently, and the second comfort sound source of bass sounds is generated constantly, so that the continuity of the comfort sound sources can be maintained while also improving musicality.

[0088] (6) According to this embodiment, the first comfort sound source of short sounds and the second comfort sound source of long sounds are employed, and therefore the roles of the two types of comfort sound sources are divided, and the discomfort caused by noise contained in environmental sounds can be further reduced. In particular, the first comfort sound source of short sounds is generated intermittently, and the second comfort sound source of long sounds is generated constantly, so that the continuity of the comfort sound sources can be maintained while also improving musicality.

[0089] (7) If it is not possible to select the noises contained in the input environmental sound, the output comfort sound source may be complicated. Furthermore, when normal noise with a large peak and steady noise with a small peak occur simultaneously, only the normal noise with a large peak may be converted, and the steady noise may not be converted. Furthermore, if all input environmental sounds are converted, for example, non-noise sounds may be converted. Furthermore, the number of converted sounds may increase, resulting in a complex sound source that is unpleasant. Therefore, in this embodiment, by dividing the conversion process (flow) into two parts (steps S30 to S34, steps S40 to S44) and adding a conversion sound determination process (steps S30 and S40), this problem is solved by dealing with steady noise while not converting unnecessary sounds. This not only reduces the discomfort of steady noises such as the engine noise of heavy machinery, but also allows for the selection of noises to be converted, even for noises with large peaks, thereby more effectively reducing discomfort.

[0090] [Modifications] The present invention is not limited to the above-described embodiment, and can be practiced in various modified forms.

[0091] (1) In the above-described embodiment, an example was described in which the first noise was a normal noise and the second noise was a steady noise, but the first noise may be a steady noise and the second noise may be a normal noise. Furthermore, the first noise is not limited to a normal noise or a steady noise, and the second noise may be a specific noise and a predetermined noise different from the specific noise.

[0092] (2) A specified noise level need not be set. (3) The predetermined noise level may be the same for the first noise and the second noise. (4) The feature information input section does not need to be provided.

[0093] (5) In the above-described embodiment, the first comfort sound source is a high-pitched sound and the second comfort sound source is a low-pitched sound. However, the first comfort sound source may be a low-pitched sound and the second comfort sound source may be a high-pitched sound.

[0094] (6) In the above-described embodiment, the first comfort sound source is a melody sound and the second comfort sound source is a bass sound. However, the first comfort sound source may be a bass sound and the second comfort sound source may be a melody sound.

[0095] (7) In the above-described embodiment, the first comfort improvement sound source is a short sound and the second comfort improvement sound source is a long sound. However, the first comfort improvement sound source may be a long sound and the second comfort improvement sound source may be a short sound.

[0096] (8) It is sufficient to adopt at least one of the combinations of high and low notes, melody notes and bass notes, and short and long notes, and it is not necessary to adopt any combination at all.

[0097] (9) In the above-described embodiment, the output of the audio signal is intentionally delayed so that the audio signal is output a predetermined time after the noise is collected, but instead, the audio signal may be output immediately. In this case, the first sound source and the second sound source are output at approximately the same time as the user hears the noise.

[0098] (10) In the above-described embodiment, a touch panel is used for the feature information input unit 13. Alternatively, an operation menu may be displayed on the display and input of feature information by the user may be accepted by accepting operations on the operation menu using an input device such as a mouse or keyboard.

[0099] Furthermore, all of the illustrated embodiments are merely preferred examples, and can be modified as appropriate when implementing the present invention. [Explanation of symbols]

[0100] 10 Environmental Sound Improvement System 11 Input section 12 Judgment section 13. Feature information input section 14 Conversion unit 15 Output section M1 The first pleasant sound source M2 Second Sound Source M3 The first pleasant sound source M4 Second Sound Source S1 Normal noise S2 Steady noise DS Digital Signage

Claims

1. an input unit to which noise is input; a determination unit that determines whether the noise input to the input unit is a first noise or a second noise based on the frequency of the noise; a conversion unit that converts the first noise into a spectrum and converts it into a first comfort sound source based on the spectrum, and converts the second noise into a spectrum and converts it into a second comfort sound source based on the spectrum; an output unit that outputs the first comfort sound source and the second comfort sound source; An environmental sound improvement system equipped with:

2. The environmental sound comfort system according to claim 1, The environmental sound comfort system is characterized in that the conversion unit converts the first noise or the second noise that exceeds a predetermined noise level into the first comfort sound source or the second comfort sound source.

3. The environmental sound comfort system according to claim 2, The environmental sound comfort system is characterized in that the predetermined noise level is different between the first noise and the second noise.

4. The environmental sound comfort system according to claim 1, The environmental sound comfort system is characterized in that the conversion unit converts the first noise into the first comfort sound source of high pitch, and converts the second noise into the second comfort sound source of low pitch that is lower in pitch than the first comfort sound source.

5. The environmental sound comfort system according to claim 1, The environmental sound comfort system is characterized in that the conversion unit converts the first noise into the first comfort sound source of a melody sound, and converts the second noise into the second comfort sound source of a bass sound.

6. The environmental sound comfort system according to claim 1, The environmental sound comfort system is characterized in that the conversion unit converts the first noise into the first comfort sound source of a short sound, and converts the second noise into the second comfort sound source of a long sound that is longer in duration than the first comfort sound source.

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