EP4651521A1

EP4651521A1 - Method for adjustment of acoustic signals of multiple loudspeakers

Info

Publication number: EP4651521A1
Application number: EP24175328.4A
Authority: EP
Inventors: Ovidiu Marcel Maghear; Vlad-Laviniu Ghete; Andrei Calugaru
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2024-05-13
Filing date: 2024-05-13
Publication date: 2025-11-19

Abstract

The invention relates to a method for adjustment of acoustic signals of multiple loudspeakers (102, 103) at the position of a sound receiving device (101) comprising: determining, in a measuring step (207), for each of the multiple loudspeakers (102, 103), a position of the respective loudspeaker relative to the position of the sound receiving device (101), adapting, in an adjustment step (208), at least one operating parameter related to a magnitude of the acoustic signal of the loudspeaker, for at least one of the multiple loudspeakers (102, 103), based on the positions of the multiple loudspeakers (102, 103) relative to the sound receiving device (101), so as to adjust the magnitude of the acoustic signal, for the multiple loudspeakers (102, 103) at the position of the sound receiving device, determining, in a validation step, for each of the multiple loudspeakers (102, 103), a magnitude of the acoustic signal of the loudspeaker at the position of the sound receiving device, by means of the sound receiving device (101), and, if a difference between the magnitudes of at least two of the multiple loudspeakers (102, 103), at the position of the sound receiving device exceeds a pre-defined threshold, repeating the adjustment step.

Description

The present invention relates to a method for the adjustment of acoustic signals emitted from multiple loudspeakers at the position of a sound receiving device.

Background of the invention

US 2019/0058949 A1 discloses a public address system for the sonication of a sonication region.

Disclosure of the invention

According to the invention, a method for adjustment of acoustic signals, a computing device and a computer program having the features of the independent claims are proposed. Advantageous embodiments are subject of the dependent claims and the following description.
Loudspeakers, in particular, wireless loudspeakers, can have different power outputs and specifications. When connecting or paring multiple loudspeakers, the sound emitted from each loudspeaker at a given position might not be equal for each loudspeaker, however. This can be due to different specifications, in particular different power-outputs of the individual loudspeakers, but can also related to the position of the loudspeakers relative to a user, who would then perceive different volume levels from each loudspeaker.
The present invention provides a way to adjust or even equalize a magnitude of acoustic signals of multiple loudspeakers at the position of a sound receiving device.
In a measuring step, for each of the multiple loudspeakers, a position of the respective loudspeaker relative to a sound receiving device is determined. Such relative position can be a distance, for example. Such sound receiving device can be a smartphone or part of a smartphone, e.g., a microphone of the smartphone.
In an adjustment step, an operating parameter related to the magnitude of the acoustic signal of at least one of the multiple loudspeakers is adapted, based on the positions of the multiple loudspeakers relative to the sound receiving device, so as to equalize the magnitude of the acoustic signal of the multiple loudspeakers at the position of the sound receiving device. This might include sending instructions to the respective loudspeaker or its control unit such that the magnitude of the acoustic signal is changed. For example, if for one of two loudspeakers, a much higher volume (i.e., magnitude of the acoustic signal) is perceived at the position of the sound receiving device, than for the other one, for this one loudspeaker the parameters can be adapted so as to lower the volume. Of course, such adaption is possible for more than one of the multiple loudspeakers. It is noted that the specification and/or configuration of specific loudspeakers typically allow to adapt the operating parameters so as to result at least essentially at the desired volume.
In a validation step, for each of the multiple loudspeakers, a magnitude of the acoustic signal of the loudspeaker at the position of the sound receiving device is determined. This can be done using the sound receiving device and recording an acoustic signal of each of the loudspeakers. If a difference between the magnitudes of at least two of the multiple loudspeakers, at the position of a sound receiving device, exceeds a pre-defined threshold, the adjustment step is repeated.
In this way, the problem of acoustic pressure difference is solved, more exactly, the difference can even be equalized at a given point (e.g. at the user's position), via estimating the distance of each sound device (loud speaker) to the given point. The adjustment or equalization of the pressure difference can be done by knowing the full specifications of each speaker and adapting the power outputs so that at a given distance one would have the desired value, e.g. in the unit dB. Current approaches focus more on static loudspeakers, requiring the positioning of loudspeakers in the room, as well as room dimensions as input parameters, in order to adjust the sound levels of the individual loudspeakers. The proposed approach, in contrast, targets in using known parameters of loudspeakers and technology to determine or estimate distances. In particular this approach focuses on wireless speakers (SPL performance in a controlled environment), as well as on leveraging the wireless technologies from smartphones (e.g. via Bluetooth). However, the proposed method can also be applied to non-wireless speakers and other distance or relative position measurements. The latter can, for example, be used in vehicles having multiple loudspeakers.
In an embodiment, the position of the sound receiving device is determined by triangulation. In particular, this can be executed by means of wireless communication technology like Bluetooth or others or combinations of different wireless communication technologies. In this way, quick and efficient position measurements are possible, using existing hardware like smartphones.
In an embodiment, the sound receiving device is a mobile device or a part thereof, which provides means of wireless communication. A mobile device can be a smartphone, a tablet, or a laptop, for instance. In this case the mobile device should be configured to communicate wirelessly with the loudspeakers. Thus, both the loudspeakers and the mobile device provide means of wireless communication, which can in particular be hosted by Bluetooth technology, but also WLAN (WiFi) or means of wireless communication in other frequency ranges could be implemented.
Thus, the method can be executed on widely available devices using conventional means of wireless communication, so that the method of sound level adjustment is easily available to a large number of potential users.
In an embodiment, the sound level adjustment routine can be repeated, if at least one of the multiple loudspeakers is relocated. Thus, the sound levels can be realigned at the position of the mobile device. In particular, this process could be executed automatically. On the other hand, it would also be possible to repeat the sound level adjustment, if the position of the mobile device is changed. The latter can occur, for example, if the user having the mobile device moves.
The provided method will enable a dynamic adjustment of the sound pressure level, respective to the smartphones location, giving the user a balanced audio system. It enables the user to place the speakers in the desired places in the room or elsewhere. Another advantage is, if the speakers have big parameter differences, the method can compensate based on the lowest power output speaker/s.
A computing device according to the invention (a system for data processing), e.g., a processing unit of a smartphone, is configured, in particular programmatically, to perform a method according to the invention.
The invention further concerns a public address system with at least two loudspeakers and a computing device as descripted.
The implementation of a method according to the invention in the form of a computer program or computer program product with program code for performing all method steps is also advantageous, since this causes particularly low costs, especially if an executing control unit is still used for further tasks and is therefore present anyway. Finally, a machine-readable storage medium is provided with a computer program stored thereon as described above. Suitable storage media or data carriers for providing the computer program are, in particular, magnetic, optical and electrical memories, such as hard disks, flash memories, EEPROMs, DVDs and the like. It is also possible to download a program via computer networks (Internet, intranet, etc.). Such a download can take place wired or wirelessly (e.g. via a WLAN network, a 3G, 4G, 5G or 6G connection, etc.).
Further advantages and embodiments of the invention will be apparent from the description and the accompanying drawing.
The invention is shown schematically in the drawing by means of an example of an embodiment and is described below with reference to the drawing.
Short description of the figures

Fig. 1: shows an example of an arrangement for explaining the present invention.
Fig. 2: shows a flow chart of a method according to an embodiment of the present invention.

Embodiments(s) of the invention

Fig. 1 illustrates an arrangement for explaining the present invention. The exemplary arrangement comprises a mobile device 101, in particular a smartphone, and two loudspeakers 102, 103. The mobile device 101 can comprise a sound receiving device, e.g. a microphone of the smartphone. A setup with more than two loudspeakers is also possible; for example, three or four or even more loudspeakers can be provided.
The two loudspeakers 102, 103 can be located in different distances 104, 105 from the mobile device. The mobile device 101 can be connected to the loudspeakers by means of wireless communication technology, which can in particular be based on Bluetooth. Such wireless communication technology allows data communication and, in particular, also triangulation for determining distances.
In Fig. 2 a flow chart is presented, which shows a method according to the invention in an embodiment. In case of a decision being true the corresponding path is labelled 'Y', in case of the decision being false the path is labelled `N'. Reference will also be made to the arrangement shown in Fig. 1.
After starting the process, step 201, the connection between the mobile device 101 and the loudspeakers 102, 103, in particular via Bluetooth, is established, step 202. This can be initiated by the user or be performed automatically, e.g., after an initial pairing has taken place.
Subsequently, an optional check is implemented, which checks whether at least two loudspeakers are present, step 203. If this is not the case, the process stops, step 204, otherwise the process continues and waits for a user input, which starts the sound level adjustment process, step 205.
If the user chooses to start this process, a measuring step 207 is performed, in which the position of the mobile device 101 relative to the loudspeakers 102, 103 is determined, in particular by means of triangulation based on the Bluetooth signal. If the user does not start this process, the process ends, step 206.
In a subsequent adjustment step 208, operating parameters of each loudspeaker 102, 103 are adjusted such that the magnitude of the acoustic signal, i.e., the sound level, at the position of the mobile device 101 becomes similar - or at least almost similar- for each loudspeaker 102, 103. Such operating parameters allow setting the amplitude of the output signal of the loudspeaker, for example.
It is noted that it can also be sufficient to adjust the operating parameters of only one of the loudspeakers, for example, in order to raise the sound signal of one of the loudspeakers to reach the sound level the other loudspeaker has at the position of the mobile device 101.
The success of the sound adjustment step is then validated in a validation step 209 by separately checking the magnitude of the sound signal at the position of the sound receiving device 101 for each loudspeaker 102, 103. If the variation (or difference) of the sound levels of each loudspeaker 102, 103 at this position is larger than a pre-defined threshold, the sound adjustment process is repeated iteratively, until this variation is below the pre-defined threshold value, in which case the sound level adjustment is considered successful, step 210.
This pre-defined threshold can, for example, be chosen such that a human, when listening to the different sound levels cannot differentiate that these sound levels are different. Also, this pre-defined threshold can, for example, be chosen such that a certain difference of, e.g., 5% or 10% is allowed, even if a human could then hear that there is some difference.
In case of a successful sound level adjustment, the user can stop the process at step 211 and the process is finished, step 212; otherwise the adjustment can be validated again.
In the end, the sound signal from each loudspeaker 102, 103 at the position of the mobile device 101 is similar within a certain range, resulting in an improved sound experience for the user.
A major advantage of this method is the convenient implementation of the sound level adjustment, which can in particular be executed automatically. Thus, it is possible to combine loudspeakers 102, 103 with different specifications, e.g. with different emitted sound amplitudes for the same volume setting, such that the sound signal from each loudspeaker 102, 103 at position of the user is similar.
Also, in an arrangement of multiple loudspeaker 102, 103, which are unequally distanced form the sound receiving device 101, e.g. the user, the sound level at the position of the user is adjusted, so that ideally no difference in sound level between the individual loudspeakers 102, 103 is perceptible.
The position of the mobile device 101 relative to the loudspeakers 102, 103 can in particular be determined by means of triangulation, based on a wireless signal (e.g. Bluetooth). This method can be implemented by a user, who wants to equalize the sound levels of multiple loudspeakers 102, 103 at a user defined position.
Further, the method can be used in indoor environments, but also outside, for example for concert setups. It is also be possible that the method, i.e., the steps of measuring, adjustment and validation, is triggered automatically in case of pre-defined events, for instance if one of the loudspeakers 102, 103 is moved, e.g., for more than a pre-defined distance, or if the mobile device 101, or the user, respectively, change position relative to the arrangement of loudspeakers 102, 103, e.g., by more than a pre-defined distance.
Another possible use case for the described method is a vehicle environment, where an occupant carries a smartphone or other mobile device,. Then, the position of the vehicle occupant's position can be determined with respect to multiple loudspeakers in the vehicle. The method, i.e., the steps of measuring, adjustment and validation, can then also be triggered automatically, thus individually adjusting the sound amplitude of multiple speakers, depending on the occupant's position.

Claims

A method for adjustment of acoustic signals of multiple loudspeakers (102, 103) at the position of a sound receiving device (101) comprising:
determining, in a measuring step (207), for each of the multiple loudspeakers (102, 103), a position of the respective loudspeaker relative to the position of the sound receiving device (101),

adapting, in an adjustment step (208), at least one operating parameter related to a magnitude of the acoustic signal of the loudspeaker, for at least one of the multiple loudspeakers (102, 103), based on the positions of the multiple loudspeakers (102, 103) relative to the sound receiving device (101), so as to adjust, in particular equalize, the magnitude of the acoustic signal, for the multiple loudspeakers (102, 103) at the position of the sound receiving device,

determining, in a validation step, for each of the multiple loudspeakers (102, 103), a magnitude of the acoustic signal of the loudspeaker at the position of the sound receiving device, by means of the sound receiving device (101), and, if a difference between the magnitudes of at least two of the multiple loudspeakers (102, 103), at the position of the sound receiving device exceeds a pre-defined threshold, repeating the adjustment step.
A method according to claim 1, wherein the position of the sound receiving device is determined by means of triangulation.
A method according to claim 2, wherein the determination of the position of the sound receiving device by means of triangulation is executed by means of wireless communication technology.
A method according to claim 3, wherein the wireless communication technology comprises Bluetooth.
A method according to any of the preceding claims, wherein the position of the sound receiving device (101) is validated by acoustic triangulation, based on the acoustic signals of the loudspeakers (102, 103).
A method according to any one of the preceding claims, wherein a mobile device (101) comprises the sound receiving device, and wherein the mobile device (101) is configured to provide wireless communication, in particular Bluetooth.
A method according to claim 6, wherein the mobile device (101) is a smartphone or a tablet.
A method according to any of the proceeding claims, wherein each of the multiple loudspeakers (102, 103) is configured to provide wireless communication, in particular Bluetooth.
A method according to any of the preceding claims, further comprising, if at least one of the multiple loudspeakers (102, 103) has been re-located, repeating the measuring step, the adjustment step and the validation step.
A computing device comprising a processor configured to perform the method of any one of the preceding claims.
A computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the method of any one of claims 1 to 9.
A computer-readable medium on which the computer program of claim 11 is stored.