Silent communication mask comprising a movable acoustic retention element

The silent communication mask with a mobile acoustic retention element addresses the challenge of maintaining confidentiality in public spaces by using a mobile element to block unintelligible sounds, enhancing confidentiality and acoustic absorption without compromising compactness.

WO2025073769A1PCT designated stage expired Publication Date: 2025-04-10OFFICE NAT DETUDES & DE RECH AEROSPATIALES
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Patent Information

Application Number
PCT/EP2024/077755
Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Priority Date
2023-10-02
Filing Date
2024-10-02
Publication Date
2025-04-10

AI Technical Summary

Technical Problem

Nomadic workers face challenges in maintaining confidentiality during videoconferencing in public or shared spaces, as their conversations can be overheard by nearby individuals, and existing communication masks have limitations in acoustic absorption due to compactness constraints.

Method used

A silent communication mask with a mobile acoustic retention element that includes a shell with an expiration vent and a microphone, featuring a first mobile element that opens under air pressure from the user's exhalation and closes when there is no air exhalation, effectively blocking unintelligible sounds.

Benefits of technology

The mask significantly enhances confidentiality by ensuring that spoken words are unintelligible to nearby individuals, while maintaining compactness and effective acoustic absorption, even in noisy environments.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to a silent communication face mask (1) intended to be placed on the head of a user (5), comprising: - a shell (2) configured to cover the mouth and nose of the user (5), said shell (2) comprising at least one exhalation vent (14), - at least one microphone (3) carried by the shell (2) and arranged in such a way as to capture and transmit the words spoken by the user (5), - an acoustic absorber device (4) extending in the shell (2), the mask (1) comprising at least one first movable element (20) configured to adopt a configuration for opening the exhalation vent (14), under the effect of being pushed by the air exhaled by the user (5), and to adopt a configuration for closing the exhalation vent (14) in the absence of exhaled air, thus making the words spoken by the user (5) unintelligible.
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Description

[0001] Silent communication mask with a mobile acoustic retention element

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates to the field of communication masks.

[0004] In particular, it offers a silent communication mask that allows a mask user to talk to someone through the mask, without being heard by people geographically nearby.

[0005] STATE OF THE ART

[0006] In recent years, nomadic working, or teleworking, an activity that involves working from a location other than one's designated workplace, has grown considerably. This development has been driven in particular by technological advances, particularly in the field of mobile communication devices such as smartphones, tablets, and laptops, as well as by the rise of reliable and fast communication methods such as broadband internet and online collaboration tools.

[0007] The emergence of the possibility of working from anywhere poses certain problems, particularly when the chosen workplace is a public place or shared with other people nearby, for example, a train, a café, or a library. Indeed, workers may have to participate in videoconference meetings, during which they will have to discuss with colleagues or clients remotely, possibly about confidential matters. This situation, in addition to being problematic in terms of confidentiality for the worker, can also cause discomfort to those present near the worker.

[0008] Communication masks have been developed to ensure mobile workers can communicate comfortably, even in harsh or noisy environments. These devices typically consist of a sound-capturing device such as a microphone, a shell covering the user's nose and mouth, a head-mounted device, and inhaling and exhaling vents.

[0009] To solve this problem, the company SKYTED has developed a so-called silent communication mask, incorporating an acoustic absorption device.

[0010] More specifically, the proposed mask incorporates a surface trim element which comes from the invention described in patent FR3065570 and which ensures improved acoustic absorption.

[0011] This invention makes it possible to imagine surface linings absorbing acoustic waves adapting to very specific sound environments to be treated. In addition, the effectiveness of these linings depends only on their shape, and not on the materials used. The materials chosen are therefore free, depending on environmental constraints, such as temperature, mass limitations, mechanical resistance, etc. Finally, this free choice of shaping materials also allows great freedom of manufacturing methods, which can be additive manufacturing or injection molding.

[0012] This invention therefore makes it possible to effectively treat acoustic waves in very harsh environments, for example on aircraft nacelles with metallic materials and manufacturing methods by additive manufacturing. It also makes it possible to very effectively and targetedly treat noise from industrial equipment, noise from transport, such as railways, automobiles, aircraft, boats. Finally, this freedom of materials (rigid / soft) and the possibility of manufacturing by injection allows targeted and low-cost applications in domestic environments: household appliances (vacuum cleaners, heating or ventilation systems, tools, etc.).

[0013] We want to further improve the confidentiality provided by the communication mask developed with this sound-absorbing material.

[0014] In addition, communication masks have the constraint of having to be of limited size, in order to be compatible with nomadic use and allow freedom of movement for the user. The need for compactness of the mask limits the usable treatment surface for acoustic absorption, and therefore constitutes a parameter limiting the relative efficiency of acoustic absorption.

[0015] STATEMENT OF THE INVENTION

[0016] A general aim of the invention is to propose a communication mask allowing further improved confidentiality.

[0017] Communication masks have breathing vents that can allow unabsorbed acoustic waves to "radiate" and escape from the mask.

[0018] According to one aspect, the invention proposes a mask with at least a first movable element capable of adopting a configuration for opening an exhalation vent under the effect of pushing air exhaled by the user and a configuration for closing said vent in the absence of exhaled air, thus making the user's words unintelligible.

[0019] This increases the confidentiality of the mask with respect to people near the user.

[0020] This solution also has the advantage of not impacting the compactness of the mask.

[0021] To this end, the invention proposes a silent communication face mask intended to be placed on a user's head, comprising: a shell configured to cover the user's mouth and nose, said shell comprising at least one exhalation vent, at least one microphone carried by the shell and arranged so as to pick up and transmit the user's words, and an acoustic absorbing device extending into the shell.

[0022] Furthermore, the mask comprises at least a first movable element configured to adopt a configuration of opening the exhalation vent under a pushing effect of air exhaled by the user and to adopt a configuration of closing the exhalation vent in the absence of exhaled air, thus making the user's words unintelligible.

[0023] Advantageously, the first mobile element is configured to close elastically in the absence of expelled air, with a return time to the closing configuration such that the first mobile element returns to the closing configuration of the exhalation vent at the start of each pronunciation of a syllable in a group of words.

[0024] Preferably, the first movable element is configured to move into the closing configuration from the opening configuration upon stopping the exhaled air pushing force in a time of less than 250 ms. According to one embodiment, in the closing configuration the movable element is in contact with the exhalation vent. For example, the first movable element comprises a first edge fixed to an edge of the exhalation vent and a second free opposite edge.

[0025] According to another embodiment, in the closed configuration the movable element is at a distance from the exhalation vent. For example, the first movable element comprises a first edge fixed to the shell of the exhalation vent and a second free opposite edge.

[0026] Advantageously, the first movable element comprises a first edge fixed to the shell or to an edge of the exhalation vent and a second free opposite edge.

[0027] Advantageously, the first mobile element is intended to be located at a distance from the mouth of the user wearing the mask of between 4 and 26 centimeters.

[0028] In one embodiment, the first movable element is a membrane or comprises a bundle of flexible fibers.

[0029] In one embodiment, the mask comprises a second movable element arranged opposite the first movable element, the first and second movable elements extending in a plane for closing the exhalation vent when said first and second movable elements are in the closed configuration.

[0030] In another embodiment, the first movable element comprises an impeller.

[0031] In one embodiment, the shell comprises an inspiration vent, the mask comprising a third and optionally a fourth mobile elements capable of adopting an opening configuration of the inspiration vent reached under a thrust effect of incoming air inspired by the user and a closing configuration of the inspiration vent when the user does not inspire air, said third and fourth mobile elements being configured to close elastically in the absence of inspired air.

[0032] In such an embodiment, the mask comprises a first stop element blocking the opening of the exhalation vent under the effect of pushing air inspired by the user, and comprising a second stop element blocking the opening of the inhalation vent under the effect of pushing air exhaled by the user.

[0033] According to one example, the mask is configured so that the first movable element is located at a minimum distance of 4 cm from the user's mouth.

[0034] According to one example, the first mobile element as well as the distance between the first mobile element and the user's mouth are configured such that the duration between the start of expiration of air exhaled by the user and the transition from the closing configuration to the opening configuration of the first mobile element under a pushing effect of this exhaled air, referred to as the opening delay, is greater than 10% of the duration of a syllable.

[0035] Thus, when the sound of a syllable reaches the movable element, the latter is still closed and has not had time to open. Part of this sound is then blocked by the movable element and cannot escape or escape properly through the exhalation vent. The sound of this syllable is therefore inaudible for at least part of its duration. If the sound of the syllable is very short, it may be blocked by the movable element for its entire duration. The sound of the syllable may also be blocked by the movable element for only part of its duration, making the syllable or word barely or not at all intelligible.

[0036] For example, the opening delay is greater than 10% of the duration of any syllable, preferably pronounced in French, preferably so as to be intelligible.

[0037] According to one example, the opening delay is greater than 20%, preferably 50%, and preferably 80% of the duration of a syllable.

[0038] According to one example, the opening delay is greater than 10 ms and preferably 50 ms and preferably 80 ms and preferably 100 ms

[0039] According to one example, the first movable element is configured, in particular its dimensions, its mass and its elasticity, so that the opening time is greater than the duration of a syllable, preferably of any syllable pronounced in the French language.

[0040] According to one example, the first mobile element as well as the distance between the first mobile element and the user's mouth are configured so that the duration, called the lag duration, between the arrival of a sound of a syllable on the mobile element and the transition from the closing configuration to the opening configuration of the first mobile element under a thrust effect of this exhaled air, is greater than 10% of the duration of this syllable.

[0041] Thus, when the sound reaches the movable element 20, the latter is still closed and has not had time to open. Part of this sound is then blocked by the movable element and cannot escape or escape correctly through the exhalation vent, making the syllable or word unintelligible.

[0042] According to one example, the offset duration is greater than 20%, preferably 50%, and preferably 80% of the duration of a syllable, preferably of any syllable pronounced in the French language.

[0043] According to one example, the offset duration is greater than 10 ms and preferably 50 ms and preferably 80 ms and preferably 100 ms. DESCRIPTION OF THE FIGURES

[0044] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0045] Figure 1 illustrates a communication mask according to one embodiment of the invention worn by a user;

[0046] Figure 2 schematically illustrates the communication mask of Figure 1 in top view;

[0047] Figure 3A illustrates an example of a first and a second movable element according to a first embodiment, in front view, in the closed configuration;

[0048] Figure 3B illustrates the first and second movable elements according to the first embodiment, in top view, in the open configuration;

[0049] Figure 3C illustrates an example of a first and a second movable element according to a second embodiment, in top view, in the opening configuration;

[0050] Figure 4 illustrates an example of a first and a second movable element according to a third embodiment, in front view;

[0051] Figure 5A illustrates an example of a first and a second movable element according to a fourth embodiment, in front view, in the closed configuration;

[0052] Figure 5B illustrates an example of a first and a second movable element according to the fourth embodiment, in top view, in the opening configuration and in the closing configuration;

[0053] Figure 5C illustrates an example of a third and a fourth movable elements according to an embodiment, in top view, in closed configuration and in open configuration;

[0054] Figure 6A schematically illustrates an example of a sonogram of the 1 er forming the syllable “no” and the effects of the mask according to the invention on intelligibility for a person not wearing the mask;

[0055] Figure 6B schematically illustrates an example of a sonogram of the 1 erforming the syllable “bab” and the effects of the mask according to the invention on intelligibility for a person not wearing the mask;

[0056] Figure 6C schematically illustrates an example of a sonogram of the 1 er forming the syllable “gag” and the effects of the mask according to the invention on intelligibility for a person not wearing the mask;

[0057] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION OF THE INVENTION

[0058] Example of general mask structure:

[0059] The communication mask 1 illustrated in Figures 1 and 2 comprises a shell 2, at least one microphone 3 and an acoustic absorbing device 4. Fasteners 6 make it possible to hold the mask in position on the head of a user 5.

[0060] The shell 2 is configured to cover the mouth and preferably the nose of the user 5. An inner surface 8 of the shell 2 defines a cavity 12 surrounding the mouth and preferably the nose of the user 5 when the mask 1 is worn by the latter, for example in particular by means of a mouthpiece 13.

[0061] The microphone 3 is arranged in the shell 2 and configured to capture the acoustic waves emitted by the user 5 to transmit them remotely, for example to a mobile phone via communication electronics.

[0062] The sound-absorbing device 4 is arranged on a portion of the inner surface 8 of the shell 2. More precisely, the sound-absorbing device 4 forms an inner lining of the cavity 12. It is thus arranged to be in the path of the sound waves emitted by the user 5 wearing the mask 1 while speaking and is for example constituted by a surface trim element as described in the document FR3065570. The sound-absorbing device 4 thus makes it possible to at least partially acoustically absorb the sound waves emitted by the user 5 while not being sealed against the air exhaled by the user 5, which can escape from the cavity 12 by passing through said sound-absorbing device 4.

[0063] Event(s) and moving elements:

[0064] The shell 2 comprises one or more exhalation vents 14, for example arranged on lateral surfaces 10, 11 of the shell 2, other locations of the shell 2 being of course conceivable such as for example an outer surface 9 of the shell 2 opposite the inner surface 8.

[0065] An exhalation vent 14 consists for example of an opening in the shell 2 opening onto the outside of the mask 1 on the one hand and communicating with the cavity 12 via the acoustic absorber device 4 on the other hand, so that the air exhaled by the user 5 can escape from the mask 1 after having escaped from the cavity 12 by passing through the acoustic absorber device 4. For example and as shown in the figures, the exhalation vent 14 can be of a rectangular shape with a length of between 1 and 3 centimeters, and a width of between 2 and 4 millimeters.

[0066] Furthermore, the mask 1 comprises at its vent(s) 14 at least one mobile element 20 configured to chop up the sound likely to come out through the vent 14 and make the words escaping from the mask 1 at least partially unintelligible for a person located near the user 5 wearing the mask 1.

[0067] More specifically, the mobile element 20 is configured to adopt a configuration of opening the exhalation vent 14 under a pushing effect of the air exhaled by the user 5, and to adopt a configuration of closing the exhalation vent 14 in the absence of exhaled air.

[0068] Alternatively, the movable element 20 is arranged in the shell 2 between the cavity 12 and the exhalation vent 14, and extends in a plane for closing the exhalation vent 14 in the closed configuration, as shown for example in FIGS. 1 and 2.

[0069] In one embodiment, the movable element 20 is deformable in flexion and comprises for example a flexible membrane or a bundle of flexible fibers. One of its edges 20a is attached to the edge of the exhalation vent 14 or to an inner wall of the shell 2; its other opposite edge 20b is free. Thus, the movable element 20 can either come into contact with the exhalation vent 14 or be arranged at a distance from the exhalation vent 14 as illustrated in figures 1 and 2. In the unstressed configuration, the movable element 20 closes all or part of the exhalation vent 14 and therefore occupies the closed configuration; in addition, the movable element 20 deforms in flexion under the effect of the pressure of the air exhaled by the user 5 to allow said exhaled air to escape.Several movable elements may also be provided to close the same vent, for example a first movable element 20 and a second movable element 23 formed by two membranes (as illustrated in FIGS. 3A, 3B and 3C for example) or two bundles of membranes (as illustrated in FIG. 4 for example) one opposite the other and each attached to an edge of the exhalation vent 14 or to an inner wall of the shell 2 located between the cavity 12 and the exhalation vent 14 in the plane for closing the exhalation vent 14. An embodiment with two movable elements 20 and 23 is shown in FIGS. 3A (in the closed configuration), 3B and 3C (in the open configuration), in which the second movable element 23 comprises an edge 23a attached to the edge of the exhalation vent 14 opposite the edge carrying the edge 20a of the first movable element 20, and a second free opposite edge 23b.

[0070] Thus, when the user 5 speaks or is in the exhalation phase, the air exhaled by the user 5 causes a flexural movement of the movable element 20 (if applicable, the movable elements 20, 23), which opens the exhalation vent 14. The movable element 20 is then in the configuration for opening the exhalation vent 14, as is the second movable element 23 if applicable. Figures 3B and 3C illustrate the movable elements 20, 23 in two extreme flexural positions when they are stressed by the exhalation of the user 5.

[0071] Conversely, when the user 5 stops speaking, or is in the inspiration phase, the exhaled air is stopped, stopping the pushing force previously exerted on the mobile element(s) 20, 23. Consequently, the mobile element 20 resumes the closing configuration of the exhalation vent 14, as does the second mobile element 23 if applicable, as shown in FIG. 3A.

[0072] Typically, the mobile element 20, and where appropriate the second mobile element 23, is configured to return to the closed configuration from the open configuration in a duration of less than 250 milliseconds. This duration corresponds to the minimum non-audible pause time generally observed after a series of syllables making up a word or a group of words. In this way, the mobile element 20, and where appropriate the second mobile element 23, returns to the closed configuration from the open configuration sufficiently quickly so that at the start of each syllable pronounced by the user 5 during the pronunciation of a group of words, the mobile element 20, and where appropriate the second mobile element 23, is in the closed configuration.

[0073] Such a mobile element 20, 23 deformable in bending (membrane, fiber bundle, etc.) is made of an elastic material that is sufficiently flexible to be able to be pushed and bend under the effect of the pushing force of the air exhaled by the user 5 while speaking, and sufficiently rigid to otherwise return to the closed configuration. Thus, such a mobile element 20, 23 is for example made of rubber, silicone, or elastomer in general. Such a mobile element 20, 23 may thus be an elastic material characterized by a Young's modulus of between 500 and 2500 MPa. The thickness of such a mobile element 20, 23 may be between 0.4 and 1 millimeter, in order to be thin enough to move into the open configuration under the effect of the pushing force of the air exhaled by the user 5 while speaking.

[0074] It will further be noted that, when the user 5 speaks, the emitted acoustic waves propagate at a speed of approximately 340 meters per second. The air exhaled by the user 5 while speaking propagates at an initial speed of approximately 1.3 meters per second, the acoustic waves arrive at the level of the first mobile element 20, and where appropriate also of the second mobile element 23, well before the exhaled air exerts a pushing force on said first mobile element 20, and where appropriate also on the second mobile element 23, this at the start of each syllable due to the sufficiently rapid return time to the closing configuration of the first mobile element 20 and where appropriate of the second mobile element 23.Thus, the acoustic waves emitted by the user 5 while speaking and arriving at the level of the mobile element 20 (after passage of the acoustic absorbing device 4) before the exhaled air are reflected by the first mobile element 20 in the closed configuration obstructing the exhalation vent 14, if applicable by the two mobile elements 20, 23. In this way, the acoustic waves are retained in the mask 1, which improves the overall acoustic attenuation of the mask 1. This improved acoustic attenuation is effective until the air exhaled by the user 5 comes into contact with the first mobile element 20 or with the two mobile elements 20, 23 if applicable, and thus exerts a pushing force on it / them.The movable element 20, and where appropriate the second movable element 23, then passes into the open configuration and then allows the exhaled air and the acoustic waves arriving from this moment to escape, as long as the movable element 20, and where appropriate the second movable element 23, is acted upon by such a pushing force and has not returned to the closed configuration when said pushing force stops. In this way, each syllable spoken by the user 5 is rendered partially unintelligible. Indeed, the words or syllables that can be perceived in the absence of such a movable element 20 are “chopped” so that a person near the user 5 will not be able to clearly understand said words or syllables. This unintelligibility will vary and be more or less significant depending on the syllable spoken, each syllable spoken causing a more or less early expiration and of more or less long duration depending on the language.For example, the duration of a syllable in French is between 200 and 250 milliseconds, while the duration of a syllable in Chinese is between 200 and 400 milliseconds.

[0075] In French, the average duration of a vowel is about 100 to 200 milliseconds (ms) while the average duration of a consonant is about 30 to 100 milliseconds (ms).

[0076] If the first letter, vowel or consonant, is spoken in part or entirely before the movable element 20 is pushed by the air flow, the syllable will potentially be unintelligible.

[0077] In order to optimize the effects of unintelligibility, it is necessary to respect the distance conditions between the mouth and the exhalation vent 14.

[0078] Indeed, the distance between the mouth and the first mobile element 20, or the two mobile elements 20, 23 if applicable, must make it possible to cover the shortest duration provided by a vowel or a consonant emitted in a conversation, which is of the order of 30 milliseconds. Due to the speed of the exhaled air equal to approximately 1.3 m / s, the mobile element 20, and if applicable the second mobile element 23, must be located at a minimum distance of 4 cm from the mouth, so that the exhalation of air is completed at the moment when the thrust of the exhaled air begins to be exerted on the first mobile element 20.

[0079] Similarly, a maximum distance between the movable element 20 and the mouth can be determined in order to prevent the first movable element 20, and where appropriate the second movable element 23, from being in the open configuration at the end of a syllable and remaining open until the following syllable. Nevertheless, this maximum distance is relatively large, and is generally incompatible with the need for compactness of the mask. For example, for the pronunciation of the syllable “le” or the syllable “no”, the respective emission durations of which are 200 milliseconds, the maximum distance is 26 cm.

[0080] Thus, as is clear from the above, the movable element 20, 30 is configured, in particular its dimensions, its mass and its elasticity, so that the closing time is sufficiently rapid to reach the closing configuration before the start of the pronunciation of a syllable following another syllable pronounced immediately previously.

[0081] Furthermore, preferably the movable element 20, 30 is configured so that the opening delay is sufficiently slow. More precisely, the movable element 20, 30 is configured so that the duration, called the lag duration, between the arrival of a sound of a syllable on the movable element 20, 30 and the transition from the closing configuration to the opening configuration of the first movable element 20, 30 under the effect of the thrust of the air exhaled by the user when pronouncing this syllable, is greater than 10% of the duration of the sound of this syllable. According to one example, the lag duration is greater than 20%, preferably 50%, and preferably 80% of the duration of the sound of the syllable, preferably of any syllable pronounced in the French language. According to one example, the lag time is greater than 10 ms and preferably 50 ms and preferably 80 ms and preferably 100 ms.

[0082] Thus, when the sound of the syllable reaches the movable element 20, 30, the latter is still closed and has not had time to open. Part of this sound is then blocked by the movable element 20, 30 and cannot then escape or escape correctly through the exhalation vent 14, making the syllable or word unintelligible.

[0083] Preferably, the configuration parameters of the mobile element 20, 30 are in particular its dimensions, its mass, its elasticity and its position relative to the user's mouth.

[0084] To illustrate the effects on the intelligibility of sounds escaping from mask 1, we recall below some elements on the physics of speech. In particular, vowels are the longest sounds and are easily identifiable. When a sound is emitted from the glottis of user 5, harmonics appear and are filtered by the vocal tract of user 5. A frequency spectrum of this sound is then in the form of modulated harmonics called "formants".

[0085] The presence of a vowel provides information on the presence of consonants before or after the said vowel, by a modification of the trajectory of the formants during the transitions before and after the vowel.

[0086] Consonants can be occlusive, such as "b" or "g", in which case the passage of air is temporarily blocked by an occlusion of the vocal tract during their pronunciation.

[0087] Consonants can also be oral, such as "I", in which case the soft palate is raised (or lowered in the case of so-called restrictive consonants) and air passes through the mouth.

[0088] Finally, consonants can be nasal, such as "n", in which case the vocal tract is momentarily occluded by a lowering of the soft palate while the nasal cavities allow a continuous flow of air to pass through.

[0089] Although oral and nasal consonants involve a more or less restricted expiration, the pronunciation of such a consonant may be totally or partially unintelligible depending on its duration. For example, and as illustrated in Figure 6A which schematically represents the 1st formant from a sonogram of the vowel “no”, the duration of the consonant “n”, which extends between the times t0 and t1, is greater than the opening time of the expiration vent 14 (which corresponds to the time taken by the exhaled air from the start of pronunciation of the syllable to exert a pushing force on the mobile element 20 or the mobile elements 20, 23 as the case may be, and therefore open the expiration vent 14, the opening time of the expiration vent 14 being represented by the window F), such that this consonant is partially retained by a person near the user 5 wearing the mask 1.

[0090] Conversely, as illustrated in Figure 6B which represents the 1st formant from a sonogram of the vowel “bab”, the duration of the consonant “b” (between times t4 and t5) is slightly less than the opening time of the expiration vent 14 illustrated by the window F (t4 and t5 being outside the window F), so that the letter “b” is totally retained in the mask 1, as is the beginning of the vowel “a”, which is pronounced between t5 and t6, and part of which is located outside the window F.

[0091] Similarly, Figure 6C which represents the 1 er formant resulting from a sonogram of the vowel “gag”, the duration of the consonant “g” (between times t8 and t9) is slightly greater than the opening time of the expiration vent 14 illustrated by window F (t9 being inside window F unlike t8), so that the letter “g” is partially retained in mask 1.

[0092] Thus, depending on the syllables spoken, the words are retained more or less by the at least one mobile element 20, so that the unintelligibility for a person close to the user 5 is increased.

[0093] In one embodiment, the shell 2 further comprises an inspiration vent 16 similar to the expiration vent 14. The inspiration vent 16 may be provided on one of the lateral surfaces 10, 11, for example on the second lateral surface 11, or in other words on the lateral surface opposite the lateral surface on which the expiration vent 14 is provided. Alternatively, the inspiration vent 16 may be provided anywhere on the outer surface 9 of the shell 2. The inspiration vent 16 consists for example of an opening in the shell 2, so that the user 5 can inspire air from outside the mask 1, this inspired air entering the mask through the inspiration vent 16. For example, the inspiration vent 16 may be of a rectangular shape of length and width similar to those of the expiration vent 14. Alternatively, the mask 1 may, like the exhalation vent 14, comprise a plurality of inspiration vents 16.Preferably, the total surface area of ​​the inspiration vent(s) 16 is identical to the total surface area of ​​the expiration vent(s) 14.

[0094] In an alternative embodiment, the exhalation vent 14 and the inspiration vent 16 are merged.

[0095] In an embodiment in which the exhalation vent 14 and the inspiration vent 16 are not merged and advantageously in this case, the mask 1 comprises, in a manner analogous to the exhalation vent 14, at least one third movable element 25 similar to the first movable element 20, and optionally a fourth movable element 26 similar to the second movable element 23, the third and fourth movable elements 25, 26 being at opposite edges of the inspiration vent 16, or alternatively on interior walls of the mask 1 opposite each other and located between the cavity 12 and the inspiration vent 16 (as illustrated in FIG. 2, but not in FIG. 1 for reasons of clarity).In such an embodiment, the movable elements 20, 23 on the exhalation vent 14 side may comprise a first stop element 27 configured to block the opening of said movable elements 20, 23 from the obturation plane towards the cavity 12, i.e. to block the opening of said movable elements 20, 23 during the inhalation of the user 5. Similarly, the movable elements 25, 26 on the inspiration vent 16 side may comprise a second stop element 28 configured to block the opening of said movable elements 25, 26 from the obturation plane towards the inspiration vent 16, i.e. to block the opening of said movable elements 25, 26 during the expiration of the user 5. The stop elements 27, 28 may be similar, and for example comprise protrusions 30 extending from an edge of the corresponding vent 14, 16 or from an interior wall to the mask 1.

[0096] In an alternative embodiment, the first movable element 20 is a paddle wheel. In such a case, the first movable element 20 is arranged in a housing made in the mask between the cavity 12 and the exhalation vent 14, so that the paddle wheel, which comprises an axis of rotation passing through its center, is rotated under the effect of the thrust of the air exhaled by the user 5. Thus, the first movable element 20 is arranged so that the axis of rotation of the paddle wheel is perpendicular to an axis of the housing connecting an upstream portion of the housing and a downstream portion of the housing, the downstream portion communicating with the exhalation vent 14 and the upstream portion communicating with the cavity 12 via the sound-absorbing device 4.

[0097] The diameter of the impeller is chosen so that when stationary, almost no air passes between the upstream and downstream of the impeller, i.e. a diameter of at least 95% of the minimum distance separating two opposite walls of the housing parallel to the axis of rotation of the impeller. In other words, the diameter of the impeller is chosen so that when stationary, no air passes between the blade tips and an opposite wall of the housing.

[0098] The closing configuration of the first mobile element 20 therefore corresponds to the stopping of the blade wheel, that is to say in a position of the blades closing the passage of air between the upstream and downstream of the blade wheel, in other words between the blade tips and a wall of the housing opposite.

[0099] When the user speaks or exhales air, the air exhaled by the user exerts a thrust force on the blades of the paddle wheel, setting the first mobile element 20 in rotational motion around the axis of rotation. Thus, the air lodged between the blades can pass from an upstream portion of the housing to a downstream portion of the housing, and escape from the mask 1 by joining the exhalation vent 14. The opening configuration of the exhalation vent 14 of the first mobile element 20 therefore corresponds to the rotation of the paddle wheel.

Claims

CLAIMS 1 . Silent communication face mask (1) intended to be placed on a head of a user (5), comprising: a shell (2) configured to cover the mouth and nose of the user (5), said shell (2) comprising at least one exhalation vent (14), at least one microphone (3) carried by the shell (2) and arranged so as to pick up and transmit the words of the user (5), an acoustic absorbing device (4) extending in the shell (2), characterized in that the mask (1) comprises at least a first movable element (20) configured to adopt a configuration of opening the exhalation vent (14) under a pushing effect of air exhaled by the user (5) and to adopt a configuration of closing the exhalation vent (14) in the absence of exhaled air, thus making words of the user (5) unintelligible, in which the first movable element (20) is configured to close elastically in the absence of expelled air,with a return duration in the closing configuration such that the first mobile element (20) is back in the closing configuration of the expiration vent (14) at each start of pronunciation of a syllable in a group of words., 2. Mask (1) according to claim 1, in which the first movable element (20) is configured to move into the closing configuration from the opening configuration upon stopping the force of pushing the exhaled air in a duration of less than 250 ms.

3. Mask (1) according to any one of claims 1 to 2, wherein the first movable element (20) comprises a first edge (20a) fixed to the shell (2) of the exhalation vent (14) and a second free opposite edge (20b).

4. Mask (1) according to any one of claims 1 to 2, wherein the first movable element (20) comprises a first edge (20a) fixed to one edge of the exhalation vent (14) and a second free opposite edge (20b).

5. Mask (1) according to any one of claims 1 to 4, in which the first movable element (20) is intended to be located at a distance from the mouth of the user (5) wearing the mask of between 4 and 26 centimeters.

6. Mask (1) according to any one of claims 1 to 5, in which the first movable element (20) is a membrane or comprises a bundle of flexible fibers.

7. Mask (1) according to any one of claims 1 to 6, comprising a second movable element (23) arranged opposite the first movable element (20), the first and second movable elements (20 and 23) extending in a plane for closing the exhalation vent (14) when said first and second movable elements (20 and 23) are in the closed configuration.

8. Mask (1) according to any one of claims 1 to 3, wherein the first movable element (20) comprises a paddle wheel.

9. Mask (1) according to any one of claims 1 to 8, wherein the shell (2) comprises an inspiration vent (16), the mask (1) comprising a third and optionally a fourth movable elements (25 and 26) capable of adopting an opening configuration of the inspiration vent (16) reached under a thrust effect of incoming air inspired by the user (5) and a closing configuration of the inspiration vent (16) when the user (5) does not inspire air, said third and fourth movable elements (25 and 26) being configured to close elastically in the absence of inspired air.

10. Mask (1) according to claim 9 in combination with claim 7, comprising a first stop element (27) blocking the opening of the exhalation vent (14) under the effect of the thrust of the air inspired by the user (5), and comprising a second stop element (28) blocking the opening of the inhalation vent (16) under the effect of the thrust of the air expired by the user (5).

11. Mask (1) according to any one of claims 1 to 10, configured so that the first movable element (20) is located at a minimum distance of 4 cm from the user's mouth (5).

12. Mask (1) according to any one of claims 1 to 11, in which the first mobile element (20, 30) as well as the distance between the first mobile element (20, 30) and the mouth of the user (5) are configured so that the duration between the start of expiration of air exhaled by the user (5) and the transition from the closing configuration to the opening configuration of the first mobile element (20, 30) under a pushing effect of this exhaled air, referred to as the opening delay, is greater than 10% of the duration of a syllable.

13. Mask (1) according to the preceding claim, in which the opening delay is greater than 20%, preferably 50%, and preferably 80% of the duration of a syllable.

14. Mask (1) according to any one of claims 12 or 13, wherein the opening delay is greater than 10 ms and preferably 50 ms and preferably 80 ms and preferably 100 ms.

15. Mask (1) according to any one of claims 1 to 14, wherein the first mobile element (20, 30) as well as the distance between the first mobile element (20, 30) and the user's mouth (5) are configured so that the duration, called the offset duration, between the arrival of a sound of a syllable on the mobile element (20, 30) and the passage from the closing configuration to the opening configuration of the first mobile element (20, 30) under a pushing effect of exhaled air to pronounce this syllable, is greater than 10% of the duration of this syllable.

Citation Information

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