Voice projection system for a respirator mask

Abstract

A voice projection system for a respirator mask, is disclosed The voice projection system comprises a speaker unit configured to receive an output signal from a vibration sensor mounted in a body of the respirator mask, and to amplify the received output signal. A connector is provided for mounting the speaker unit on the respirator mask. The speaker unit comprises a sensor for detecting a type of the respirator mask when the speaker unit is mounted on the respirator mask. The speaker unit is configured to select an equalisation setting based on an output from the sensor, and to apply the selected equalisation setting when amplifying the received output signal.

Description

[0001] VOICE PROJECTION SYSTEM FOR A RESPIRATOR MASK

[0002] Field of the Invention

[0003] The present invention relates to a voice projection system for a respirator mask. The voice projection system enables a voice of a wearer of the respirator mask to be amplified.

[0004] Background

[0005] A respirator mask is a device that is used to protect a wearer from dangerous materials or substances, for example chemical, biological, nuclear and radiological agents, and / or toxic industrial chemicals, and / or toxic industrial materials.

[0006] A respirator mask typically includes a nose cup that covers at least the nose and mouth of the user and provides a seal around the nose and mouth. The nose cup is provided either with a filter for filtering air inhaled into the nose cup by the user, or with a connector for connecting the nose cup to a supply of clean or filtered air. The nose cup is also typically provided with an exhale valve through which exhaled air can be discharged from the nose cup. A respirator mask can also include a visor or goggles portion that covers the eyes of the user and protects the eyes of the user. The visor or goggles portion usually provides a seal around the eyes of the user.

[0007] To facilitate communication when wearing a respirator mask, a voice projection unit may be used. Such a voice projection unit typically involves a microphone which is placed inside the nose cup to pick up the wearer’s voice, and a speaker which is connected to the microphone for projecting the wearer’s voice. The present invention has been devised in light of the above considerations.

[0008] Summary of the Invention

[0009] At is most general, the invention provides a voice projection system for a respirator mask, comprising a speaker unit that is connectable to the respirator mask. The speaker unit is configured to receive an output signal from a vibration sensor mounted in the respirator mask, and to amplify the received output signal. The microphone used with a conventional voice projection unit is susceptible to moisture build-up in the mask, which can lead to failure of the microphone overtime. In contrast, the vibration sensor used with the voice projection system of the invention is not susceptible to moisture in this way, thereby improving long-term performance of the system. The vibration sensor is mounted in the respirator mask, such that it can detect vibrations that are transmitted through a body (e.g. material) of the respirator mask. Thus, when a wearer of the mask speaks, this causes vibrations in the respirator mask which are coupled into the vibration sensor. The output signal from the vibration sensor is then amplified by the speaker unit, which can project and / or transmit the wearer’s voice depending on the configuration of the speaker unit.

[0010] According to a first aspect of the invention, there is provided a voice projection system for a respirator mask, the voice projection system comprising: a speaker unit configured to receive an output signal from a vibration sensor mounted in a body of the respirator mask, and to amplify the received output signal; and a connector for mounting the speaker unit on the respirator mask; wherein the speaker unit comprises a sensor for detecting a type of the respirator mask when the speaker unit is mounted on the respirator mask; and wherein the speaker unit is configured to select an equalisation setting based on an output from the sensor, and to apply the selected equalisation setting when amplifying the received output signal.

[0011] The invention of the first aspect thus enables the equalisation setting of the speaker unit to be automatically adjusted based on the type of mask with which the speaker unit is being used. This allows for clearer speech reproduction by the speaker unit, improving intelligibility of a wearer of the respirator mask. The first aspect of the invention is based on the realisation that different types (e.g. models) of respirator mask may have different vibration transmission properties, e.g. due to differences in material and / or shape of the respirator mask. As a result, different frequency ranges may be preferentially transmitted via the body of the mask to the vibration sensor for different types of respirator mask.

[0012] Selecting the equalisation setting for the speaker unit based on the type of respirator mask enables such differences in vibration transmission to be compensated for. In this manner, the equalisation setting for the speaker unit can be optimised for the type of respirator mask with which it is currently being used. This facilitates using the same speaker unit with a variety of different types (e.g. models) of respirator mask.

[0013] The speaker unit may be connected (or connectable) to the vibration sensor via any suitable wired or wireless connection. In some cases, the vibration sensor may be connected to the speaker unit via a wire or cable. In some cases, the vibration sensor may be integrated in the respirator mask, in which case the respirator mask may comprise a socket which the speaker unit can be plugged into for receiving the output signal from the vibration sensor.

[0014] The speaker unit may comprise a speaker (or loudspeaker) arranged to emit sound in response to detection of vibrations by the vibration sensor. In particular, the speaker may be arranged to emit the amplified output signal.

[0015] Additionally or alternatively, the speaker unit may comprise a communication module for wired or wireless communication with another device. For example, the communication module may be connected (or connectable) to a radio transmitter, for performing radio communications.

[0016] Where the speaker unit comprises a speaker and a communication module, the speaker unit may comprise a switch for selectively activating (using) one of the speaker and the communication module. The speaker unit may comprise a power source, such as a battery for powering operation of the speaker unit.

[0017] The speaker unit may comprise an amplifier (or amplifier module) for amplifying the output signal received from the vibration sensor. An output of the amplifier may be connected to the speaker and / or communication module. The speaker unit may further comprise a controller (e.g. microcontroller) or other suitable onboard electronics for controlling operation of the speaker unit.

[0018] The connector serves to mount the speaker unit on the respirator mask, e.g. so that the speaker unit is removably mountable on the respirator mask. The connector may comprise any suitable interface or engagement mechanism for engaging a corresponding mounting portion of the respirator mask, in order to mount the speaker unit on the respirator mask. As an example, the connector may be arranged to mount the speaker unit on a nosecup of the respirator mask, e.g. so that the speaker unit is arranged in front of a wearer’s mouth in use.

[0019] The connector may be implemented in a variety of ways. In some cases, the connector may be provided as a separate component to the speaker unit, such that the connector is connected between the speaker unit and the respirator mask in use. In other cases, the connector may be provided as part of the speaker unit, e.g. so that the speaker unit is directly connected to the respirator mask. For example, an interface or engagement mechanism may be integrated with a body of the speaker unit.

[0020] The sensor in the speaker unit may comprise any suitable sensor which can be used to detect a type of the respirator mask. For example, the sensor may be configured to detect an indicator (feature) when the speaker unit is mounted on the respirator mask, for determining the type of respirator mask. As an example, the sensor may be configured to detect a presence or absence of the indicator, which may be indicative of the type of respirator mask. As another example, the sensor may be configured to detect a parameter (e.g. a value, magnitude) associated with the indicator, where the parameter may be indicative of the type of respirator mask. More generally, the sensor may be adapted to a type of indicator that is to be detected for determining the type of respirator mask.

[0021] The sensor may be arranged to detect a feature on the connector and / or on the respirator mask, e.g. depending on whether the connector is a separate component from the speaker unit.

[0022] Here, the type of respirator mask may refer to a model (e.g. model number, or model range) of the respirator mask. In some cases, the type of respirator mask may refer to a specific (individual) respirator mask. For instance, the indicator may comprise an identifier for identifying the individual respirator mask. In this manner, the equalisation setting may be tailored to an individual respirator mask.

[0023] The speaker unit may comprise a controller that is configured to receive the output (e.g. output signal) from the sensor, and to select the equalisation setting based on (i.e. as a function of) the output from the sensor. For example, the controller may be configured to determine the type of the respirator mask based on the output from the sensor, and to select the equalisation setting based on the determined type of respirator mask.

[0024] The selected equalisation setting is used by the speaker unit when amplifying the received output signal from the vibration sensor. In particular, the speaker unit amplifies the signal received from the vibration sensor in accordance with the selected equalisation setting. For example, the controller may control amplification of the output signal from the vibration sensor in accordance with the selected equalisation setting. Here, an equalisation seting may refer to an amplification level for one or more predetermined frequency bands. This enables, for example, signals in a predetermined frequency band to be boosted or suppressed, to improve intelligibility of the output of the speaker unit. Thus, the equalisation setting may indicate whether the signal is to be boosted or suppressed in the predetermined frequency band relative to other frequencies. In some cases, the equalisation seting may provide an indication of amplification level for a plurality of frequency bands, e.g. the equalisation setting may provide an amplification level as a function of frequency of the signal. When amplifying the signal received from the vibration sensor, the speaker unit (controller) adjusts amplification of the signal, e.g. across the one or more predetermined frequency bands, in accordance with equalisation seting.

[0025] The equalisation setting may also be referred to as an equalisation profile.

[0026] The speaker unit may comprise a memory storing a plurality of (e.g. two or more) equalisation settings, each of the plurality of equalisation settings being associated with a respective type of respirator mask. In this manner, the speaker unit can select from its memory the equalisation setting corresponding to the determined type of respirator mask, and control amplification of the signal accordingly.

[0027] In line with the above, each of the plurality of equalisation settings may include an indication of amplification level for one or more frequency bands. The equalisation settings may be adapted to different vibration transmission properties of the different respirator mask types, to improve clarity and intelligibility of the output of the speaker unit. For example, measurements may be performed for each mask type, to determine a preferred equalisation seting for that type of mask, which can then be stored in the memory of the speaker unit.

[0028] Two or more of the plurality of equalisation setings may be configured to provide different levels of amplification of the received output signal in a first frequency band. In this manner, the speaker unit may provide different levels of amplification in the first frequency band depending on the type of respirator mask used, contributing to improving intelligibility of the wearer.

[0029] The sensor may comprise a magnetic field sensor. In this manner, the sensor may detect the presence of a magnetic field, and / or a strength (magnitude) of the magnetic field. This enables a magnet in the connector or the respirator mask to be used as a feature which can be detected by the sensor, to provide an indication of the type of respirator mask. By way of example, the magnetic field sensor may comprise a Hall effect sensor, or a reed switch.

[0030] The speaker unit may be configured to: if no magnetic field (or no magnetic field above a predetermined threshold) is detected by the magnetic field sensor, select a first equalisation setting; and if a magnetic field (or a magnetic field above the predetermined threshold) is detected by the magnetic field sensor, select a second equalisation setting. Thus, absence of a magnetic field (above the predetermined threshold) may be indicative of a first type of respirator mask being used, whilst presence of a magnetic field (above the predetermined threshold) may be indicative of a second type of mask being used. For example, the second type of respirator mask and / or the connector used with the second type of respirator mask may comprise a magnet that is arranged for detection by the sensor when the speaker unit is mounted on the respirator mask. In contrast, no corresponding magnet may be provided in the respirator mask of the first type or the connector used with the respirator mask of the first type. In this manner, the speaker unit can readily determine which of the first and second type of respirator mask it is mounted on, based on the output from the magnetic field sensor. In line with the above, the first equalisation setting and the second equalisation setting may provide different levels of amplification in the first frequency band.

[0031] In some cases, the speaker unit may be configured to select one of the plurality of equalisation settings based on a strength of the magnetic field detected by the magnetic field sensor. For example, there may be a plurality of respirator mask types, each associated with a respective magnetic field strength.

[0032] The connector may comprise a first connection portion for (removably) connecting the connector to the speaker unit, and a second connection portion for (removably) connecting the connector to the respirator mask. Thus, the connector may act as an adaptor for mounting the speaker unit on the respirator mask. In this manner, an existing speaker unit can be retrofitted onto an existing respirator mask, by providing suitably adapted first and second connection portions. The first connection portion may be adapted to engage a corresponding connection portion (connection interface) on the speaker unit, whilst the second connection portion may be adapted to engage a corresponding connection portion (connection interface) on the respirator mask. The first connection portion and the second connection portion may be arranged on opposite sides of the connector, e.g. so that they face away from one another. In this manner, the connector may be arranged between the speaker unit and the respirator mask when the speaker unit is mounted on the mask with the connector.

[0033] The sensor may be configured to detect an indicator on the connector, the indicator being associated with the type of the respirator mask. In this manner, the speaker unit can determine the type of respirator mask used based on the indicator provided in the connector. In particular, different connectors will typically be required for different mask types, e.g. due to different arrangements of connection interface on different mask types. Providing the indicator on the connector facilitates using the speaker unit of the invention with existing respirator masks, without having to fit the masks with an indicator.

[0034] The sensor may, for example, be arranged to detect presence or absence of the indicator in the connector. As another example, the sensor may be arranged to detect a type, parameter, or feature of the indicator. The output of the sensor is indicative of a detection result of the sensor, which is then used by the speaker unit to select the equalisation setting.

[0035] Where the sensor comprises a magnetic field sensor, the sensor may be configured to detect a magnet located on the connector. In other words, the indicator may comprise a magnet.

[0036] Other types of sensor and indicator may be used for detecting the type of respirator mask. By way of example, the sensor may comprise an optical sensor, in which case the indicator may comprise a visual indicator. The sensor may comprise a radio frequency identification (RFID) reader, in which case the indicator may comprise an RFID tag (e.g. storing identification information for the mask). As another example, the sensor may comprise a switch (or pressure sensor or button) which is arranged for engagement with an identification feature (e.g. a pin or other protrusion) on the connector or respirator mask when the speaker unit is mounted on the respirator mask. The speaker unit can then determine the type of respirator mask, e.g. depending on whether the switch is engaged (e.g. pressed). In some cases, the sensor can comprise multiple switches (or pressure sensors or buttons), arranged for engagement with one or more identification features when the speaker unit is mounted on the respirator mask.

[0037] Different types of respirator mask may be arranged such that different combinations of switches are engaged when the speaker unit is mounted on the respirator mask. In this manner, the speaker unit can determine the type of respirator mask as a function of which of the multiple switches is engaged.

[0038] The voice projection system comprise the vibration sensor, wherein the vibration sensor is arranged to be received in a holder in a body of the respirator mask, the vibration sensor being configured to detect vibrations transmitted within the body of the respirator mask. In contrast to a microphone which is arranged to detect soundwaves transmitted through the air, the vibration sensor is configured to detect vibrations that are transmitted through the body (material) of the respirator mask). Thus, the vibration sensor need only be in contact with the body of the respirator mask, and so can be placed outside the breathing space inside the respirator mask, avoiding risk of moisture damage to the vibration sensor. Herein, vibrations transmitted within the body of the respirator mask refers to vibrations transmitted (propagated) within a material of the respirator mask. To detect (receive) the vibrations, the vibration sensor is arranged to contact the body of the respirator mask, so that the vibrations are coupled into the vibration sensor.

[0039] The vibration sensor may be connected to the speaker unit via any suitable connection. In some cases, the vibration sensor may be connected to the speaker unit via a flexible cable that extends from the speaker unit.

[0040] The vibration sensor may comprise any suitable sensor for detecting vibrations transmitted within the body of the respirator mask. The vibration sensor may, for example, comprise a vibration transducer and / or an accelerometer, which provides an output signal that varies as a function of detected (sensed) vibrations). The output signal from the vibration sensor may correspond to a speech signal that represents (varies as a function of) speech of a wearer of the respirator mask.

[0041] The vibration sensor may comprise a housing, e.g. in which the transducer and / or accelerometer is located, to protect the sensor from the environment. In some cases, the housing may be airtight, e.g. sealed. In other words, the vibration sensor may be encapsulated. In some cases, the vibration sensor may be overmoulded with a protective material to form an airtight enclosure around the vibration sensor. Such a housing or encapsulation around the vibration sensor may protect it from the environment.

[0042] When the vibration sensor is received in the holder in the body of the respirator mask, the vibration sensor is in contact with the body of the respirator mask. In this manner, vibrations transmitted within the body of the respirator mask are coupled into the vibration sensor.

[0043] The vibration sensor may be shaped to form an interference fit with the holder in the body of the respirator mask. In other words, a shape of the vibration sensor may be complementary to a shape of the holder. This may ensure good mechanical coupling between the vibration sensor and the respirator mask, to provide effective detection of vibration. The holder may, for example, be in the form of a pocket or cavity formed in the body of the respirator mask. The holder may be arranged outside a breathing space of the respirator mask. In this manner, the vibration sensor is located outside the breathing space, and so is not exposed to moisture within the breathing space. For example, the holder may be arranged on an outside of the respirator mask, such that the vibration sensor is mountable on an outside (exterior) of the respirator mask. In some cases, the vibration sensor may be adapted (e.g. shaped) to be received in a drinks coupler pocket on an outside of the respirator mask. In this manner, the vibration sensor can be mounted in a pre-existing pocket provided in the respirator mask.

[0044] According to a second aspect of the invention, there is provided a voice projection system for a respirator mask, the voice projection system comprising: a speaker unit configured to receive an output signal from a vibration sensor mounted in a body of the respirator mask, and to amplify the received output signal; a connector for mounting the speaker unit on the respirator mask; and one or more vibration dampers arranged to dampen transmission of vibrations between the respirator mask and the speaker unit when the speaker unit is mounted on the respirator mask.

[0045] When the speaker unit is mounted on the respirator mask, vibrations from the speaker unit (e.g. resulting from sounds emitted by the speaker unit) may couple into the respirator mask such that they can be picked up by the vibration sensor and be re-amplified by the speaker unit, leading to a feedback loop. Indeed, the vibration sensor may be sensitive to any vibrations in the respirator mask body, making it susceptible to feedback. According to the first aspect, one or more vibration dampers are provided to dampen transmission of vibrations between the speaker unit and the respirator mask, thus preventing (or reducing) occurrence of such a feedback loop. This enhances performance of the voice projection system, and improves intelligibility of the wearer of the respirator mask.

[0046] The voice projection system of the second aspect may include any of the features described above in relation to the first aspect of the invention. In particular, any of the features described for the first aspect relating to the speaker unit, the connector, and / or the vibration sensor may be shared with the third aspect of the invention. Likewise, any features described in relation to the second aspect are applicable to the first aspect of the invention.

[0047] As discussed above, the one or more vibration dampers serve to dampen (e.g. reduce, inhibit, or prevent) transmission of vibrations between the speaker unit and the respirator mask. In other words, the one or more vibration dampers may be arranged to vibrationally isolate the speaker unit from the respirator mask. This reduces or prevents vibrations arising in the speaker unit (e.g. due to sounds emitted by the speaker unit) from coupling into the respirator mask.

[0048] The one or more vibration dampers may be arranged to dampen transmission of vibrations between the speaker unit and the respirator mask via the connector.

[0049] The one or more vibration dampers may be arranged to provide a break in one or move vibration transmission paths between the speaker unit and the respirator mask. For example, the one or more vibration dampers may be arranged at one or more connection points between the connector and the respirator mask, and / or at one or more connection points between the speaker unit and the connector. Accordingly, vibrations emitted by the speaker unit must pass through the one or more vibration dampers to reach the respirator mask, ensuring effective damping of vibration transmission.

[0050] The one or more vibration dampers may comprise any suitable material with vibration damping, absorbing, and / or isolating properties. Typically, such a vibration damping material may be relatively soft and flexible. Examples of materials that can be used as vibration dampers include rubber materials (e.g. butyl), silicone, thermoplastic elastomers (TPEs), neoprene, foam materials, sponge materials, etc. The material of the vibration dampers may be resistant to chemicals that may be present in the environment, to avoid degradation of the vibration dampers.

[0051] In contrast, the connector may comprise a relatively rigid material, such as a rigid (hard) plastic or similar. Thus, the one or more vibration dampers may be formed of a different material compared to the material of the connector, e.g. the one or more vibration dampers may have a greater flexibility than a rigid material of the connector. Similarly, a housing of the speaker unit may comprise a relatively rigid material, such as a hard (rigid) plastic or similar. Thus, the one or more vibration dampers may be formed of a different material compared to the housing, e.g. the one or more vibration dampers may have a greater flexibility than a rigid material of the housing.

[0052] The one or more vibration dampers may comprise a vibration damper on the connector. Providing a vibration damper on the connector may provide effective vibration isolation between the speaker unit and the respirator mask, as the connector may otherwise constitute one of the main paths for vibration transmission between the speaker unit and the respirator mask. In particular, the connector may typically be in close contact with the speaker unit and the respirator mask, such that incorporating a vibration damper into the connector provides effective vibration isolation. In some cases, multiple (one or more) vibration dampers may be provided on the connector. In line with the above, the connector may comprise one or more vibration dampers arranged to be at one or more connection points between the connector and the respirator mask, and / or at one or more connection points between the speaker unit and the connector.

[0053] Where a vibration damper is provided on the connector, the vibration damper may cover a portion of the connector. This may facilitate integration of the vibration damper with the connector, and ensure effective damping of vibration transmission via the connector. The portion of the connector may be made of a more rigid material than the vibration damper. In this manner, the more rigid material of the connector provides a rigid structure for connecting the speaker unit to the respirator mask, whilst the vibration damper reduces transmission of vibrations via the connector. The portion of the connector which is covered by the vibration damper may be a portion arranged to engage the speaker unit, or a portion arranged to engage the respirator mask. Thus, the connection between the respirator mask and the speaker unit may pass through the vibration damper, i.e. the vibration damper is mechanically coupled between the speaker unit and the respirator mask. As an example, the vibration damper may be overmoulded onto the portion of the connector.

[0054] The one or more vibration dampers may comprise a vibration damper on an outer surface of the speaker unit. This may serve to avoid or reduce transmission of vibrations via the outer surface of the speaker unit. For instance, the vibration damper may be arranged on a portion of the outer surface of the speaker unit that is engaged by the connector, to inhibit transmission of vibrations via the connector. The outer surface of the speaker unit may comprise multiple vibration dampers, e.g. each arranged for engagement with a respective connection portion of the connector. In some cases, the vibration damper may cover the outer surface of the speaker unit, e.g. the vibration damper may be overmoulded onto the outer surface of the speaker unit.

[0055] As described above in relation to the first aspect, the connector may comprise a first connection portion for (removably) connecting the connector to the speaker unit, and a second connection portion for (removably) connecting the connector to the respirator mask.

[0056] The first connection portion may comprise an arm projecting from the connector to connect the connector to the speaker unit, and the one or more vibration dampers may comprise a vibration damper on the arm. In this manner, transmission of vibrations via the arm may be prevented or reduced. As an example, the vibration damper may cover the arm, i.e. a portion of the arm that engages the speaker unit. For instance, the vibration damper may be bonded to, overmoulded onto, or otherwise attached to the arm. The arm may comprise a material having a greater rigidity than the vibration damper. Alternatively, the arm may be at least partially formed of a vibration damping material, e.g. so that the arm forms the vibration damper. The first connection portion may comprise a plurality of projecting arms for connecting the connector to the speaker unit. Each projecting arm may have a respective vibration damper as described above. Additionally or alternatively, a vibration damper may be provided on a surface of the speaker unit that is engaged by the arm, e.g. in an engagement portion for the arm on the speaker unit.

[0057] The speaker unit may comprise an engagement portion for receiving the arm, and the vibration damper on the arm may be compressed within the engagement portion when the arm is received in the engagement portion. In this manner, the arm may be securely held in the engagement portion, enhancing a strength of the connection between the connector and the speaker unit. Thus, the vibration damper may serve the dual functions of reducing vibration transmission and securing the speaker unit to the connector. The vibration damper may comprise a suitable compressible material, e.g. such as the materials mentioned above.

[0058] The engagement portion may, for example, comprise a cavity, groove, or other suitable feature on the outer surface of the speaker unit arranged to receive the arm. A dimension (e.g. width) of the engagement portion may be smaller than a corresponding dimension (e.g. width) of the vibration damper on the arm, such that the vibration damper is compressed when the arm is received in the engagement portion.

[0059] Where the first connection portion comprises a plurality of projecting arms, the speaker unit may comprise a plurality of engagement portions, each arranged to receive a respective one of the projecting arms. The voice projection system may further comprise the vibration sensor, the vibration sensor being arranged to be received in a holder in a body of the respirator mask, the vibration sensor being configured to detect vibrations transmitted within the body of the respirator mask. According to a third aspect of the invention, there is provided a connector for connecting a speaker unit of a voice projection system to a respirator mask, the connector comprising: a first connection portion for connecting the connector to the speaker unit; a second connection portion for connecting the connector to the respirator mask; and one or more vibration dampers arranged to dampen transmission of vibrations between the respirator mask and the speaker unit when the first connection portion is connected to the speaker unit and the second connection portion is connected to the respirator mask. The connector of the third aspect may be used as part of the voice projection system of the first aspect and / or the second aspect. Thus, any features of the connector described above in relation to the preceding aspects are equally applicable to the connector in the third aspect.

[0060] The connector may also be referred to as an adaptor bracket.

[0061] According to a fourth aspect of the invention, there is provided a respirator mask comprising a voice projection system according to the first aspect or the second aspect of the invention.

[0062] The respirator mask may comprise a body arranged to cover at least part of a wearer’s face. The body of the respirator mask may thus comprise a nose cup arranged to define a breathing space (cavity) around the wearer’s nose and mouth. A sealing arrangement may be provided around a periphery of the breathing space, to form a seal against the wearer’s skin.

[0063] The respirator mask may further comprise a visor (or goggles) portion arranged to cover the wearer’s eyes. The visor may comprise a sealing arrangement for forming a seal around the wearer’s eyes. The visor portion and nose cup may be provided as a single unit, or they may be provided as separated parts, e.g. which may be connectable together.

[0064] The respirator mask may comprise one or more straps for holding the respirator mask on the wearer’s head.

[0065] The invention includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided.

[0066] Summary of the Figures

[0067] Embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying figures in which:

[0068] Fig. 1a shows a perspective view of a respirator mask and a voice projection system according to an embodiment of the invention, where the voice projection system is disassembled is disconnected from the respirator mask;

[0069] Fig. 1b shows a perspective view of the voice projection system mounted on the respirator mask;

[0070] Fig. 2 shows a perspective view of the voice projection system, where a connector and speaker unit of the voice projection system are disconnected from one another; Fig. 3 shows a side view of the voice projection system, where the connector is attached to the speaker unit;

[0071] Fig. 4 shows a schematic drawing illustrating components of the speaker unit; and

[0072] Fig. 5 shows an example equalisation setting for the speaker unit.

[0073] Detailed Description of the Invention

[0074] Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

[0075] A voice projection system 100 according to an embodiment of the invention is shown in Figs. 1a, 1b, and 2. The voice projections system 100 is for use with a respirator mask 102, shown in Figs. 1a and 1b. The voice projection system 100 includes a speaker unit 104 and a connector 106 for mounting the speaker unit 104 on the respirator mask 102. Fig. 1a shows an exploded view where the speaker unit 104, connector 106, and respirator mask 102 are disconnected from one another. Fib. 1b shows a perspective view where the speaker unit 104 is mounted onto the respirator mask 102 with the connector 106.

[0076] The speaker unit 104 is connected to a vibration sensor 108 via a wire (or cable) that extends from a housing of the speaker unit 104. The speaker unit 104 is configured to receive an output signal from the vibration sensor 108, and to amplify the received output signal so that the signal can be emitted by a loudspeaker and / or transmitted by a communication module. Operation of the speaker unit 104 is described in more detail below in relation to Fig. 4.

[0077] The respirator mask 102 is configured to form a seal around a face of a person wearing the mask. The respirator mask 102 comprises a body with a nose-cup 110 arranged to define a breathing space (cavity) around the nose and mouth of the wearer. The respirator mask 102 further includes a visor portion 112 connected to the nose-cup 110, and arranged to enclose an ocular space around the wearer’s eyes. The visor portion 112 comprises a transparent or partially transparent material arranged to be held in front of the wearer’s eyes, so that the wearer can see through the visor 104. A sealing arrangement is provided around a periphery of the breathing space and the ocular space, to prevent ingress of hazardous gases or substances into the respirator mask 102. The sealing arrangement may also be arranged to isolate the breathing space from the ocular space. The sealing arrangement may be formed of a flexible elastomeric material, to form a substantially air-tight seal against the wearer’s skin. The respirator mask 102 can be held in place over the face of the wearer using one or more straps, for example one or more head straps 114. A connector 116 is provided on the nose-cup 110 for connecting the nose-cup 110 to a supply of filtered or clean air. For example, an air filter can be connected to the connector 116, for filtering air inhaled into the breathing space in the nose-cup. Alternatively, the connector 116 may be connected to a source of breathable gas, for example a container or tank of breathable gas, which is typically pressurised (e.g. , a container of compressed breathable gas), or to an external air filter. The respirator mask 102 further comprises an outlet valve or exhale valve 118 that is configured to allow flow of gas in a direction from the inside of the mask to the surrounding environment and to prevent flow of gas in a direction from the surrounding environment to the inside of the mask. Therefore, air or gas breathed out by the wearer can be discharged from the mask 102. In the example shown, the exhale valve 118 is arranged so that it is located in front of the wearer’s nose and mouth.

[0078] The connector 106 comprises a first connection portion in the form of a plurality of projecting arms 120 for connecting the connector 106 to the speaker unit 104. The plurality of projecting arms 120 to grip sides of the speaker unit 104, to hold the speaker unit 104 on the connector 106. The speaker unit includes engagement portions in the form of cavities (or grooves, indentations) 122 on its outer surface, each cavity arranged to receive a respective one of the projecting arms 120 from the connector 106. Fig. 3 shows a side view of the voice projection system 100, where the speaker unit 104 and the connector 106 are connected together, with each of the projecting arms 120 received in a corresponding cavity on the speaker unit 104.

[0079] The connector 106 further comprises a second connection portion in the form of a connecting arm 124 which is arranged to engage the nose-cup 110. For example, the connecting arm 124 may comprise a catch for locking the connector 106 into position on the nose-cup 110. Additionally, the connector 106 may include a connection interface arranged for engagement with a corresponding interface on the nosecup 110, e.g. to interlock the connector 106 with the nose-cup 110. For instance, the connection interface may comprise a bayonet-type connection interface or the like.

[0080] The first connection portion (projecting arms 120) and the second connection portion (connecting arm 124) are arranged for connection to the speaker unit 104 and the respirator mask 102 on opposite sides of the connector 106, respectively. Thus, in use, the connector 106 is connected between the speaker unit 104 and the nose-cup 110, e.g. as shown in Fig. 1b.

[0081] The respirator mask 102 comprises a drinking tube 126 which is connected to the nose-cup, so that the wearer can drink through the tube 126 when wearing the mask. An end of the drinking tube 126 is provided with a coupler (or connector) 128, e.g. for connecting the drinking tube 126 to a bottle or flask. A holder (e.g. pocket) 130 is provided in the body of the respirator mask 102, e.g. under the exhale valve 118, for receiving the drinking tube coupler 128. In this manner, when the drinking tube 126 is not in use, the coupler 128 can be stowed in the holder 130.

[0082] The vibration sensor 108 is adapted (e.g. shaped, dimensioned) to be mountable in the holder 130. For example, a shape of a housing of the vibration sensor 108 may approximately match a shape of the coupler 128, so that the vibration sensor 108 can be received in the holder 130 instead of the coupler 128. The connector 106 is provided with an additional holder 132, which is arranged to receive the drinking tube coupler 128. In this manner, when the voice projection system 100 is used with the respirator mask 102 and the vibration sensor 108 is mounted in the holder 130, the drinking tube coupler 128 can instead be held in the holder 132 on the connector 106.

[0083] When the vibration sensor 108 is mounted in the holder 130, it is physically coupled to (i.e. in contact with) the body (e.g. material) of the respirator mask 102. In this manner, the vibration sensor 108 can detect vibrations that are transmitted (propagated) within the material of the respirator mask 102. The vibration sensor 108 may be shaped such that it forms an interference fit with the holder 130, to ensure effective coupling of vibrations from the respirator mask 102 into the vibration sensor 108. Accordingly, when the wearer of the respirator mask 102 speaks, this may cause vibrations in the material of the respirator mask 102, which can be detected by the vibration sensor 108 and then amplified by the speaker unit 104. The vibration sensor 108 may include any suitable type of sensor for detecting vibrations in the material of the respirator mask 102. For example, the vibration sensor 108 may comprise a vibration transducer (e.g. a piezoelectric transducer) or an accelerometer. An output signal from the vibration sensor may be indicative (representative) of the detected vibrations.

[0084] Whilst the vibration sensor 108 is shown to be received in the drinks coupler holder 130 in the described embodiment, different ways of mounting the vibration sensor 108 in the respirator mask may be used in other embodiments. For example, in other embodiments, a dedicated holder may be provided in the body of the respirator mask for holding the vibration sensor. Additionally or alternatively, means for securing the vibration sensor to a surface of the respirator mask may be provided.

[0085] A set of vibration dampers is provided for damping transmission of vibrations between the speaker unit 104 and the respirator mask 102 when the speaker unit 104 is mounted on the respirator mask 102. This serves to avoid or reduce a feedback loop in the voice projection system 100, which may arise due to transmission of vibrations from the speaker unit 104 to the respirator mask 102 (and hence to the vibration sensor 108 in the respirator mask 102). The vibration dampers may be arranged at any suitable locations, to minimise transmission of vibrations from the speaker unit 104 to the connector 106 (and therefore to the respirator mask 102). In particular, vibration dampers may be arranged such that any contact between the connector 106 and the speaker unit 104 is via one or more vibration dampers. In some embodiments, vibration dampers are provided on the connector 106, for damping transmission of vibrations between the speaker unit 104 and the connector 106. In an example, each of the projecting arms 120 on the connector 106 is covered with a vibration damping material. For instance, each of the projecting arms 120 may be formed of a rigid material onto which a vibration damping material is overmoulded or otherwise bonded. In this manner, contact between the projecting arms 120 and the speaker unit 104 is via the vibration damping material on the projecting arms 120. The projecting arms 120 may constitute the regions where there is the strongest contact between the connector 106 and the speaker unit 104, such that providing vibration damping material on the arms 120 may significantly reduce transmission of vibration between the two parts. The cavities 122 on the speaker unit which receive the projecting arms 120 may be dimensioned such that the vibration damping material on the projecting arms 120 is compressed within the cavities 122 when the connector 106 is attached to the speaker unit 104. This may ensure that the connector 106 effectively grips the speaker unit 104, whilst inhibiting transmission of vibration between the two parts. Vibration dampers may also be provided at other locations on the connector 106. For example, one or more vibration dampers may be placed on a surface 134 of the connector that faces towards the speaker unit 104 when the connector 106 is attached to the speaker unit 104, so that the one or more vibration dampers are arranged between the connector 106 and the speaker unit 104.

[0086] Additionally or alternatively, vibration dampers may be provided on the speaker unit 104. For example, vibration dampers may be provided in the cavities 122 on the surface of the speaker unit 104, such that the projecting arms 120 contact the speaker unit via the vibration dampers in the cavities.

[0087] The vibration dampers (e.g. on the connector 106 and / or the speaker unit 104) may comprise any suitable material with vibration damping, absorbing, and / or isolating properties. Typically, such a vibration damping material may be relatively soft and flexible. Examples of materials that can be used as vibration dampers include rubber materials (e.g. butyl), silicone, thermoplastic elastomers (TPEs), neoprene, foam materials, sponge materials, etc.

[0088] In the embodiment shown, the connector 106 is provided separately from the speaker unit 104. However, in other embodiments, the connector 106 may be integrated as part of the speaker unit 104, i.e. a connection interface may be provided directly on the speaker unit 104 for connecting the speaker unit 104 to the respirator mask 102. In such a case, vibration dampers may be arranged on the speaker unit 104 and / or the respirator mask 102, such that contact between the speaker unit 104 and the respirator mask 102 is via one or more vibration dampers.

[0089] Fig. 4 shows a schematic functional diagram of the speaker unit 104, illustrating various example components of the speaker unit 104. The speaker unit 104 comprises an amplification module 400 which is connected to receive and amplify the output signal from the vibration sensor 108. The amplification module 400 may comprise any suitable arrangement of amplifiers for amplifying the signal from the vibration sensor 108. The speaker unit 104 may further comprise a loudspeaker 402 which is connected to an output of the amplification module 400, such that the loudspeaker 402 is arranged to emit (project) sound corresponding to the amplified signal. The speaker unit 104 may additionally or alternatively include a communication module 404 connected to an output of the amplification module 400. The communication module 404 may be configured to transmit the amplified signal to a remote device. For instance, the communication module 404 may comprise a radio transmitter for transmitting the amplified signal, and / or a connector for connecting the speaker unit 104 to an external communication device. Where the speaker unit 104 includes both the loudspeaker 402 and the communication module 404, the speaker 104 may comprise a switch 136 (see e.g. Fig. 1b) for selecting which one of the loudspeaker 402 and the communication module 404 is coupled to the output of the amplification module 400.

[0090] The speaker unit 104 further comprises a controller 406 which is configured to control the amplification module 400. In particular, the controller 406 can control (e.g. adjust) a level of amplification applied by the amplification module 400 to the received signal from the vibration sensor 108. An internal power source (e.g. a battery) 405 is provided in the speaker unit 104 for powering operation of the speaker unit 104. In some embodiments, the speaker unit 104 is configured to recognise a type (e.g. model) of the respirator mask 102 on which it is mounted, and to select an equalisation setting as a function of the type of respirator mask 102. To achieve this, the controller 406 is connected to a sensor 408 for detecting a type of the respirator mask 102. An example location of the sensor 408 in the speaker unit 104 is shown in Fig. 2. The controller 406 is configured to determine a type of the respirator mask 102 as a function of an output from the sensor 108, and to control an equalisation setting of the amplification module 400 based on the determined type of the respirator mask 102.

[0091] In the example shown, the sensor 408 is arranged to detect an indicator 410 located in the connector 106 (indicated in Fig. 2). The connector 106 may be specifically adapted to the type (e.g. model) of the respirator mask 102. In particular, the second connection portion of the connector 106 (e.g. arm 124, connection interface) which is arranged to attach the connector 106 to the respirator mask 102 may be adapted to fit the specific mask type which it is designed to be used with. Thus, different connectors 106 (having different second connection portions) may be provided for different types (models) of respirator mask 102. Accordingly, the indicator in the connector 106 can be used to provide an indication of the type of mask which is currently being used with the speaker unit 104.

[0092] Various types of sensor 408 and indicator 410 may be used. As an example, the sensor 408 in the speaker unit 104 may comprise a magnetic field sensor, in which case the indicator 410 may comprise a magnet. For instance, the magnetic field sensor may comprise a Hall effect sensor or a reed switch. The magnet may be provided on or in the connector 106, such that the sensor 408 can detect the magnetic field from the magnet when the connector 106 is attached to the speaker unit 104. In some cases, the connector 106 for a first type of respirator mask may not include any magnet, whilst the connector 106 for a second type of respirator mask may include a magnet. Accordingly, if the sensor 408 does not detect any magnetic field (or if no field above a predetermined threshold is detected), then the controller 406 may determine that a first type of respirator mask is being used. On the other hand, if the sensor 408 detects a magnetic field (e.g. above a predetermined threshold), then the controller 406 may determine that a second type of respirator mask is being used. Alternatively, the controller 406 may determine the type of respirator mask based on a strength of the magnetic field, e.g. the connectors for different types of respirator mask may be provided with magnets of different strength.

[0093] Where the connector 106 is integrated as part of the speaker unit 104, the sensor 408 may be arranged to detect an indicator located in the respirator mask 102 for determining the type of respirator mask. Other types of sensor 408 and indicator can also be used for detecting the type of respirator mask. For example, the sensor 408 could comprise an optical sensor (e.g. a photodiode) which is arranged to detect an indicator on a surface of the connector 106 or the respirator mask 102 when the speaker unit 104 is mounted on the respirator mask 102. As another example, the sensor 408 could comprise an RFID reader arranged to read identification information stored in an RFID tag located in the connector 106 or the respirator mask 102. As a further example, the sensor 408 could include a pressure sensor (or button or switch) which is arranged to be engaged by an identification feature, such as a pin or other protrusion on the surface of the connector 106.

[0094] The speaker unit 104 further comprises an internal memory 412 that stores a plurality (two or more) equalisation settings, each equalisation setting being associated with a respective type of respirator mask. The memory 412 is accessible by the controller 406, and may be implemented using any suitable type of memory, such as a non-volatile computer memory. Once the controller 406 has determined the type of the respirator mask from the output of the sensor 408, the controller selects the equalisation setting stored in the memory 412 that is associated with the determined type of respirator mask, and applies the selected equalisation setting to the amplification module 400. In this manner, the amplification module 400 amplifies the signal received from the vibration sensor 108 in accordance with the selected equalisation setting.

[0095] Fig. 5 shows an example of an equalisation setting 500 that may be stored in the memory 412. The equalisation setting (or profile) 500 comprises an indication of amplification level in each of a plurality of frequency bands. The amplification level for a frequency band may indicate a level (amplitude) of the output signal from the amplification module 400 relative to the level of the received signal from the vibration sensor 108 in that frequency band. Thus, when the amplification module 400 amplifies the signal received from vibration sensor 108, it may provide different amplification levels for the different frequency bands in accordance with the equalisation setting. In this manner, certain frequency bands may be boosted or suppressed, depending on the selected equalisation setting. In the example shown in Fig. 5, the amplitude of the signal may be boosted in lower frequency bands relative to higher frequency bands. The equalisation setting for each respirator mask type is configured to enhance clarity and intelligibility of the wearer’s voice following amplification by the amplification module 400. In particular, vibrations may be transmitted differently in different types of respirator mask, e.g. due to constructional differences between the mask types (e.g. differences in materials used, shape of the masks, etc.). As a result, for example, different mask types may have a different frequency response in terms of transmission of vibrations to the vibration sensor 108. Therefore, by tailoring the equalisation profile to the mask type, it is possible to improve speech intelligibility, e.g. by boosting frequency bands that are reduced for that mask type. Various techniques may be used for determining the equalisation settings that are stored in the memory 412. For example, each mask type may be tested to determine which frequency bands (or frequencies) should be adjusted (e.g. boosted or reduced) to improve intelligibility. For instance, Speech Intelligibility Testing (STI) measurements may be performed to determine a frequency response for each mask type, by measuring speech transmission through the mask across a plurality of frequency bands. In such measurements, a mask wearer’s speech is detected using microphones located inside the mask and outside the mask. The detections from the two microphones can then be compared, to determine which frequency bands are suppressed or boosted by the mask. This can then be used to determine the equalisation setting for that mask type, e.g. by configuring the equalisation setting to boost frequency bands that are suppressed by that mask type and / or to reduce frequency bands that are increased by that mask type.

[0096] Following determination of the equalisation settings for the different mask types, the equalisation settings can be stored in the memory 412 for use by the controller 406. The memory 412 may also store information relating to the indicator or sensor output that is associated with each mask type, to enable the controller 406 to determine which mask type is currently being used based on the output from the sensor 408.

[0097] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

[0098] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

[0099] For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.

[0100] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise” and “include”, and variations such as “comprises”, “comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0101] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means for example + / - 10%.

Claims

Claims:

1. A voice projection system for a respirator mask, the voice projection system comprising:a speaker unit configured to receive an output signal from a vibration sensor mounted in a body of the respirator mask, and to amplify the received output signal; anda connector for mounting the speaker unit on the respirator mask;wherein the speaker unit comprises a sensor for detecting a type of the respirator mask when the speaker unit is mounted on the respirator mask; andwherein the speaker unit is configured to select an equalisation setting based on an output from the sensor, and to apply the selected equalisation setting when amplifying the received output signal.

2. A voice projection system according to claim 1, wherein the speaker unit comprises a memory storing a plurality of equalisation settings, each of the plurality of equalisation settings being associated with a respective type of respirator mask.

3. A voice projection system according to claim 2, wherein two or more of the plurality of equalisation settings are configured to provide different levels of amplification of the received output signal in a first frequency band.

4. A voice projection system according to any preceding claim, wherein the sensor comprises a magnetic field sensor.

5. A voice projection system according to claim 4, wherein the speaker unit is configured to:if no magnetic field is detected by the magnetic field sensor, select a first equalisation setting; andif a magnetic field is detected by the magnetic field sensor, select a second equalisation setting.

6. A voice projection system according to any preceding claim, wherein:the connector comprises a first connection portion for connecting the connector to the speaker unit, and a second connection portion for connecting the connector to the respirator mask; andthe sensor is configured to detect an indicator on the connector, the indicator being associated with the type of the respirator mask.

7. A voice projection system according to claim 6 and one of claims 4 and 5, wherein the sensor is configured to detect a magnet located on the connector.

8. A voice projection system according to any preceding claim, further comprising one or more vibration dampers arranged to dampen transmission of vibrations between the speaker unit and the respirator mask when the speaker unit is mounted on the respirator mask.

9. A voice projection system for a respirator mask, the voice projection system comprising:a speaker unit configured to receive an output signal from a vibration sensor mounted in a body of the respirator mask, and to amplify the received output signal;a connector for mounting the speaker unit on the respirator mask; andone or more vibration dampers arranged to dampen transmission of vibrations between the speaker unit and the respirator mask when the speaker unit is mounted on the respirator mask.

10. A voice projection system according to claim 8 or 9, wherein the one or more vibration dampers comprise a vibration damper on the connector.

11. A voice projection system according to claim 10, wherein the vibration damper covers a portion of the connector.

12. A voice projection system according to any preceding claim, wherein the one or more vibration dampers comprise a vibration damper on an outer surface of the speaker unit.

13. A voice projection system according to any of claims 8 to 12, wherein the connector comprises a first connection portion for connecting the connector to the speaker unit, and a second connection portion for connecting the connector to the respirator mask.

14. A voice projection system according to claim 13, wherein the first connection portion comprises an arm projecting from the connector to connect the connector to the speaker unit, and the one or more vibration dampers comprise a vibration damper on the arm.

15. A voice projection system according to claim 14, wherein the speaker unit comprises an engagement portion for receiving the arm, and the vibration damper on the arm is compressed within the engagement portion when the arm is received in the engagement portion.

16. A voice projection system according to any preceding claim, further comprising the vibration sensor, wherein the vibration sensor is arranged to be received in a holder in a body of the respirator mask, the vibration sensor being configured to detect vibrations transmitted within the body of the respirator mask.

17. A connector for connecting a speaker unit of a voice projection system to a respirator mask, the connector comprising:a first connection portion for connecting the connector to the speaker unit; a second connection portion for connecting the connector to the respirator mask; and one or more vibration dampers arranged to dampen transmission of vibrations between the respirator mask and the speaker unit when the first connection portion is connected to the speaker unit and the second connection portion is connected to the respirator mask.

18. A respirator mask comprising a voice projection system according to any of claims 1 to 16.

Images