WO2022170381A1

WO2022170381A1 - Voice amplification device

Info

Publication number: WO2022170381A1
Application number: PCT/AU2022/050054
Authority: WO
Inventors: Peter Skinner
Original assignee: Peter Skinner
Priority date: 2021-02-11
Filing date: 2022-02-02
Publication date: 2022-08-18
Also published as: AU2022219147A1

Abstract

A voice transmission device for transmitting a voice on one side of a barrier, such as a face mask or other barrier, to another side of the barrier. The device includes a voice detection module for picking up a voice on one side of the barrier. The device also includes a voice reproduction module for reproducing the voice on the other side of the barrier. Embodiments of the invention are adapted for transmission of a voice on one side of a barrier to another side of the barrier, such as a face mask or a face shield, which provide a physical barrier over the wearer's face or at least their mouth.

Description

VOICE AMPLIFICATION DEVICE TECHNICAL FIELD

[001] The present invention relates to the devices, methods and systems for voice reproduction or amplification. The invention is particularly adapted for use in relation to face masks used as personal protective equipment in hazardous environments such as in mining, chemical and medical settings. However, it is to be appreciated that the invention may be adapted for other applications.

BACKGROUND

[002] Workers in mines and in other hazardous environments are often required to don personal protective equipment (PPE). PPE can include boots, gloves, helmets, protective clothing as well as eye, ear and breathing protection. The PPE protects workers against adverse health consequences from noise, contaminants and airborne particles. Prolonged exposure to these environments without adequate PPE can result in adverse health outcomes from the inhalation of airborne dust or hazardous compounds.

[003] Workers in other sectors can also be exposed to environmental factors that present a risk to health and safety. Face masks and/or face shields, in combination with other PPE, are commonly employed to protect workers in settings such as manufacturing plants, fibreglass workshops, paint & chemical plants, hospitals, medical centres and clinics. The main benefit of wearing a face mask and/or face shield is to protect workers from exposure to harmful pathogens and airborne contaminants.

[004] Face masks and/or face shields make communication more difficult to hear, especially if the work environment has some level of noise. Face masks and/or face shields muffle high frequency speech sounds and block visual cues. This may be frustrating for workers where face masks and/or face shields are mandatory. Frequently, workers will remove their face mask or shield to communicate with others. Such improper use of PPE can present a serious health risk. [005] Accordingly, a need exists for a means for transmitting the voice of a wearer of a face mask and/or a face shield. A need exists for a means for transmitting the voice of the wearer that can be used with existing and unmodified face masks and/or face shields. A need exists for a means for transmitting the voice of the wearer of a face mask and/or face shield that is relatively easy to use. A need exists for a relatively inexpensive solution for transmitting the voice of the wearer of a face mask and/or face shield.

[006] Existing devices for voice amplification are designed as an integral part of the face mask and/or face shield. This means the device is designed specifically for use with a particular type of mask.

[007] W09215369A1 discloses an electrical amplifier unit which is removably attachable to a full-face, gas mask. The device comprises a housing that contains a microphone for detecting voice sounds emitted by the wearer of a full- face gas mask, circuitry for amplifying the detected sound, and a loudspeaker for emitting the amplified sounds externally of the mask. Accordingly, this reference calls for a specific type of full-face gas mask employed in settings where the highest level of PPE is required and a specific form of coupling of the housing of the device to the nose portion of the mask.

[008] GB2081550A discloses a device comprising a microphone housed in a receptacle attached to the outside of a mask that picks up vibrations through the mask and converts them to an electrical signal. The output signal is fed to a speaker box carried on the wearer's body to produce a sound output which is audible to other persons in the vicinity of the wearer. The receptacle containing the microphone is secured to the outside of the mask such as by an adhesive. The receptacle is connected by a cord to a speaker box which is operable to reproduce the wearer’s voice. Accordingly, this reference calls for a specific type of mask for voice amplification.

[009] Each of the above device is specifically designed for voice amplification with a special form of the face mask. Accordingly, a need exists for a voice amplification device that is designed separately attachable to any face masks and/or face shields available on the market.

[0010] Any discussion of background art throughout the specification should in no way be considered as an admission that any of the documents or other material referred to was published, known or forms part of the common general knowledge.

SUMMARY OF THE INVENTION

[0011] Accordingly, the invention provides a voice transmission device for transmitting a voice on one side of a barrier, such as a face mask or other barrier, to another side of the barrier, the device including: a voice detection module for picking up a voice on one side of the barrier; and a voice reproduction module for reproducing the voice on the other side of the barrier.

[0012] Embodiments of the invention are adapted for transmission of a voice on one side of a barrier to another side of the barrier, such as a face mask or a face shield, which provide a physical barrier over the wearer’s face or at least their mouth. Advantageously, embodiments of the invention can be used by workers wearing face marks or shields in order to communicate without having to remove their face mask or shield and encourages proper use of PPE.

[0013] Embodiments of the invention are adapted for transmission of a voice across other types of protective barriers, such as acrylic screens used as barriers in customer facing settings such as retail.

[0014] In an embodiment, the voice detection module and the voice reproduction module are contained in an integral housing for attachment to one side of the barrier.

[0015] Preferably, the housing is configured to be attached to a side of the barrier opposite to the source of the voice. [0016] In another embodiment, the voice detection module is contained in a first housing attached to a side of the barrier the same as the source of the voice and the voice reproduction module is contained in a second housing attached to a side of the barrier opposite to the source of the voice.

[0017] Preferably, the voice detection module is adapted to convert the sound of the voice into a signal that is transmitted wirelessly to the voice reproduction module.

[0018] Preferably, the voice detection module includes a first coil for transmitting the signal and the voice reproduction module includes a second coil for receiving the signal.

[0019] In addition or alternatively, the voice detection module and the voice reproduction module may be configured to transmit a signal therebetween using a wireless communication hardware and protocols, preferably including an inductive coupling between two nearby loop antennas forming an air-core transformer. An example of an inductive loop coupling arrangement and associated protocol is the near-field communication (NFC) protocol. Accordingly, the first and second coil may be comprised of first and second loop antennas forming air air-core transformer for transmitting data therebetween.

[0020] In addition or alternatively, the voice detection module and the voice reproduction module may be configured to transmit data using UHF radio waves. For example, the voice detection module and the voice reproduction module may each include either or both a transmitter and a receiver adapted to transmit and receive UHF radio signals and associated control circuitry to encode and decode signals. An embodiment of the wireless UHF radio wave data transmission protocol includes the Bluetooth protocol.

[0021] Preferably, the voice detection module and the voice reproduction module comprise one or more magnets to retain the modules together on either side of the barrier. [0022] In yet another embodiment, the voice detection module and the voice reproduction module are interconnected by a wire.

[0023] Preferably, the voice detection module is adapted to convert the sound of the voice into a signal that is transmitted through the wire to the voice reproduction module.

[0024] Preferably, the voice detection module and the voice reproduction module are interconnected by a clip that is adapted to be mounted at an edge of the barrier. Preferably, the voice detection module and the voice reproduction module comprise one or more magnets to retain the modules together on either side of the barrier.

[0025] In still yet another embodiment, the voice detection module and the voice reproduction module are interconnected by a pin that penetrates through the barrier.

[0026] Preferably, the voice detection module is adapted to convert the sound of the voice into a signal that is transmitted through the pin to the voice reproduction module.

[0027] In embodiments, the voice detection module includes a microphone transducer that generates an output signal that is provided to the voice reproduction module as an input for reproducing the voice.

[0028] Preferably, the microphone transducer comprises a micro electromechanical system (MEMS) transducer.

[0029] Preferably, the device includes a digital signal processor for receiving the output signal and isolating any unwanted noise to provide a clearer signal representing the voice.

[0030] Preferably, the device further includes a digital-to-analogue converter that converts an output signal from the digital signal processor to an analogue output signal. [0031] In embodiments, the device includes an analogue amplification circuit including an analogue preamplifier and volume control and one or more analogue filters.

[0032] Preferably the analogue filters include a low pass filter and/or a high pass filter. Preferably, the low pass filter is configured to eliminate frequencies above about 3400Hz and the high pass filter is configured to eliminate low frequencies below about 300 Hz.

[0033] Preferably, the voice reproduction module includes an audio power amplifier that amplifies the analogue output signal.

[0034] Preferably, the voice reproduction module includes a loudspeaker transducer that receives the amplified output signal from the amplifier to reproduce the voice detected by the microphone transducer.

[0035] In embodiments, the device includes a voice activated switch or a touch sensitive switch, such as a capacitance or a resistance switch, switch activated by touch to activate the voice transmission device.

[0036] Preferably, the device further comprises a battery that is rechargeable through a micro-USB cable or a wireless inductive coupling with a charging station.

BRIEF DESCRIPTION OF THE FIGURES

[0037] The present invention will now be described in more detail with reference to preferred embodiments illustrated in the accompanying figures, wherein:

[0038] Figure 1 illustrates a schematic representation of an embodiment of a voice amplification device comprising a voice detection module and a voice reproduction module. [0039] Figures 2 and 3 illustrate an exemplary embodiment of a voice amplification device comprising a voice detection module and a voice reproduction module as a single integrated device.

[0040] Figures 4 and 5 illustrate a diagrammatic representation of the voice amplification device embodiment of Figures 2 and 3 wherein the voice amplification device is attachable to a face mask.

[0041] Figures 6 and 7 illustrate another exemplary embodiment of a voice amplification device comprising a voice detection module and a voice reproduction module coupled together on either side of a continuous barrier, such as by a magnetic attraction therebetween and including wireless signal transmission, such as by an inductive coil coupling.

[0042] Figure 8 illustrates a diagrammatic representation of the embodiment of Figures 6 and 7 comprising a voice amplification device attachable to a face mask with a voice detection module located inside the mask and a voice reproduction module located outside the mask.

[0043] Figure 9 illustrates another exemplary embodiment of a voice amplification device comprising a voice detection module and a voice reproduction module with a wire connection.

[0044] Figure 10 illustrates a diagrammatic representation of Figure 9 comprising a voice amplification device attachable to a face mask with a voice detection module and a clip that hooks around the edge of the mask and a voice reproduction module located outside.

[0045] Figure 11 illustrates a schematic representation of another embodiment of the device comprising a voice amplification device attachable to a face mask with a voice detection module and a voice reproduction module with a wire connection therebetween, wherein the device includes a completely analogue circuit and a bandpass filter. [0046] Figure 12 illustrates a diagrammatic representation of the device of Figure 11 attached to a face mask with the voice detection module located inside the mask and the voice reproduction module located outside the mask.

[0047] The invention will now be described in further detail with reference to the embodiments illustrated in the Figures.

DETAILED DESCRIPTION

[0048] The present invention broadly relates to a voice amplification device. Devices according to embodiments of the invention are adapted for transmitting human voice through the barrier of existing face masks and/or the face shields available on the market without making any changes or modifications to the existing face masks and/or the face shields. The device is provided separately to the face masks and/or face shields and can be reusable. As such, while disposing of or replacing the used face masks or shields, the device can be simply removed from the used face mask or shield and attached to a new face mask or shield without disposing of the device which makes the device more cost-effective.

[0049] In broad terms, the invention includes a voice transmission device for transmitting a voice on one side of a barrier, such as a face mask or other barrier, to another side of the barrier. The device includes a voice detection module for picking up a voice on one side of the barrier and a voice reproduction module for reproducing the voice on the other side of the barrier. In embodiments where the device is used with a face mask or a face shield, the device provides a means for transmitting the voice of the wearer of the face mask or face shield so that their voice is audible to others. In embodiments, the device is adapted for use with existing and unmodified face masks and/or face shields.

[0050] Figure 1 illustrates a schematic representation of an embodiment of a voice amplification device comprising a voice detection module and a voice reproduction module. The voice detection module comprises a microphone transducer for converting a person’s voice into an electrical signal and a buffer amplifier which functions as an impedance converter to provide a usable analogue output to the audio signal. The voice detection module also includes an analogue-to-digital converter for converting the analogue electrical signal from the microphone transducer into a digital signal. A digital signal processor receives the digital signal and carries out desired processing such as to isolate and eliminate any sounds or effects to enable a clear rendition of a person’s voice to be reproduced.

[0051] The voice reproduction module includes a digital-to-analogue converter and a control circuit for switching the device on and off or for muting or unmuting the device. An audio power amplifier receives an analogue audio signal from the digital to analogue converter. A loudspeaker included in the voice reproduction module receives signal from the amplifier which results in reproducing the sound of the voice original picked up by the microphone.

[0052] As will be apparent from the foregoing description, embodiments of the device have different forms in which certain components of the device are allocated otherwise between the voice detection module and the voice reproduction module and in which signals are provided either through a wired or wireless connection therebetween. In embodiments, analogue signals are transmitted wirelessly via amplitude modulation (AM) or frequency modulation (PM) transmitters and receivers. In embodiments, digital signals are transmitted wirelessly via a UHF radio wave data transmission protocol including the Wi-Fi and/or the Bluetooth protocol. In an embodiment, signals are transmitted wirelessly through inductive loop coupling, preferably via the near-field communication (NFC) protocol.

[0053] Figures 2 to 5 illustrate an exemplary embodiment of the invention wherein the voice amplification device 10 including a housing 12 adapted to be coupled to a continuous barrier such as a face mask 2, as illustrated in Figure 5. The housing 12 contains components of the device 10 including a voice detection module comprising a microphone transducer 20, a buffer amplifier, an analogue-to-digital converter 30, a digital signal processor 40. The housing 12 also contains a voice reproduction module comprising a digital-to-analogue converter, an audio power amplifier 50 and a loudspeaker 60. Both the voice detection module and the voice reproduction module can be implemented on a solid-state integrated circuit on a chip. In this embodiment, the voice detection module and the voice reproduction module are wire connected and are integrated as one single device.

[0054] As illustrated in Figures 2 and 3, the voice detection module includes a microphone transducer 20 that functions to pick up sound and then converts the sound into an electrical signal, i.e., analogue input signal. The analogue input signal can be amplified by a buffer amplifier which functions as an impedance converter to provide a usable analogue output to the audio signal chain. The analogue-to-digital converter 30 can be used to convert the amplified analogue input signal to a digital output signal. As the digital output signal typically has a high sample rate, a decimator can be employed to filter the high sample rate digital signal to a defined sampling rate and format the digital signal to a standard digital audio format. For example, the digital output signal is defined in accordance with a pulse density modulation (PDM) format. Preferably, the microphone transducer 20, the buffer amplifier and the analogue-to-digital converter 30 can be integrated as a Microelectromechanical systems (MEMS) microphone. Accordingly, the microphone output can be applied directly to a digital circuit such as a digital signal processor (DSP).

[0055] In embodiments, the loudspeaker 60 is comprised of a MEMS transducer or of a plurality of MEMS transducers in an array. The arrangement of the MEMS transducers in an array enables a louder sound, or sound pressure level (SPL), to be generated by adding the outputs of a number of the individual MEMS transducers. In embodiments in which the loudspeaker 60 is comprised of an array of MEMS transducers, the signals that are provided to the MEMS transducers to cause them to generate sound are in phase. The MEMS transducers, which are arranged adjacent to each other and in a line, generate sound waves that are in phase and cause sound wave superposition, or constructive interference, to thereby simulate a line array or line source which results in a relatively higher sound intensity at certain distances from the MEMS transducers for a given amount of power. In another embodiment, the MEMS transducers are configured in a planar array. [0056] In another embodiment, the signals that are provided to the MEMS transducers to cause them to generate sound are controlled in order to control any phase differential or phase disparity between the MEMS transducers. In embodiments, the phase disparity can be controlled to deliberately cause interference between the sound waves originating from the MEMS transducers. The interference between the sound waves from the MEMS transducers results in the sound waves adding together to form a combined sound wave of larger amplitude. Thus, the phase of s signal provided to an array of MEMS transducers can be controlled to cause sound wave superposition, or constructive interference, resulting in the volume of sound from the array arriving at a point to be increased, from the same amount of power. In embodiments, the phase and/or the frequency range, of the signals provided to the MEMS transducers can be controlled using a digital signal processor (DSP).

[0057] In an embodiment, the DSP may be configured to be adjusted in real time. In embodiments employing DSP, the DSP is configured to adjust the phase and/or the frequency range, of the signals provided to the MEMS transducers, in real time and without latency. In an embodiment, the digital signal processor is coupled to a receiver that is configured to receive a signal from a transmitter embedded in a second one of devices 10 with which to calibrate the DSP to control the interference of the sound emitted from the MEMS speaker array to ensure that the amplitude of the sound waves received at the location of the other like device is at a highest possible level. In such an embodiment, the second device 10 may include a microphone, such as a MEMS microphone, that in response to sound waves incident on the microphone, is configured to generate a signal that is received by a processor in the second device 10. The processor in the second device 10 transmits data via the transmitter that is indicative of the amplitude of the sound incident on the microphone. The transmitted data is received by a receiver in the first device 10 which is then used by the DSP on-board to calibrate the signal sent to the array of MEMS speakers in the first device 10 to thereby control the loudness of certain frequencies of sound emitted from the MEMS array, or the constructive interference of sound waves emitted therefrom, to maximise the amplitude of the sound waves, such as at certain frequencies including, received at the location of the second device 10.

[0058] The digital signal processor 40 is provided for processing the digital output signal. The digital signal processor 40 is configured to receive the output signal and isolate any unwanted noise to provide a clearer signal representing the voice of the wearer of the face mask or face shield. In addition, the digital signal processor 40 can perform natural language processing to determine instructions, commands, and/or tasks that are to be performed.

[0059] As illustrated in Figures 2 and 3, the voice reproduction module includes a digital-to-analogue converter that converts above processed digital output signal to an analogue output signal that is provided to the speaker. The voice reproduction module also includes an audio power amplifier 50 that amplifies the analogue output signal and/or format the signal to drive the loudspeaker 60 which in turn generates a corresponding acoustic output.

[0060] The voice reproduction module further includes a control circuit for switching the device 10 on and off or the voice reproduction module to a mute or unmute condition. The control circuit is connected between the digital-to- analogue converter 30 and the audio power amplifier 50. The control circuit is operable to mute or unmute the device in accordance with instructions by the user.

[0061] In an embodiment, the control circuit includes a manually operable switch or a touch sensitive switch such as a capacitance or conductance switch that responds to a user’s touch to turn on or off the device 10. For example, when the user touches the device, it changes the logical level which subsequently changes the voltage in the control circuit. As the control circuit is in a series-series type connection within the voice reproduction module, the control circuit then defines and switches the voice reproduction module into a mute or an unmute state. [0062] The device 10 further comprises a rechargeable battery contained within the housing 12. For example, the device 10 further includes a charging port on the side of the housing 12 to charge the battery through a micro-USB. Alternatively, without a charging port, the device 10 can be charged using wireless charging such as Qi standard for wireless power transfer using inductive charging over distance of up to 4cm.

[0063] Referring to Figure 4, housing 12 is a generally cylindri cally shaped member with a generally circular shaped cross-section. However, it is to be appreciated that the housing 12 may be comprised of other shapes and configurations. The housing 12 includes a first end 11 for connection to the outwardly facing surface 3 of the mask 2. The microphone 20 is mounted at the first end 11 of the housing 12 to pick up sounds and vibrations through the surface 3 of the mask 2. The first end 11 of the housing 12 includes a touch sensitive adhesive 13 located about the periphery of the microphone 20 for adhering to the outside surface 3 of the mask2 or face shield without any penetration. Alternatively, the adhesive portion 13 may be comprised of a hook and fastener arrangement or a glue or otherwise may contain a magnet that is adapted to couple with a metallic object in the mask surface 3 or on the inside of the mask 2.

[0064] The housing 12 is sealed against ingress of liquid water or water vapour. The housing 12 is comprised of a moulded polymer shell that is lightweight and durable. The housing 12 may be formed out of a plurality of components, preferably two components wherein one part is formed with a hollow internal cavity to receive and house the internal components described herein and the second part is provided to enclose the cavity and is attachable to the first part by way of a fastener or by a deformable plastic detent. The housing 12 may also be provided with moisture proof membranes sealing openings through which sound may pass relative to the microphone transducer 20 and the loudspeaker 60.

[0065] Figure 5 illustrates an exemplary connection of the device 10 to a face mask such as for use in a hazardous work environment such as in a mine. A second end 14 of the housing 12 opposite the first end 11 faces outwardly and the loudspeaker 60 is mounted at the second end 14 to project sound from the loudspeaker 60 to others. The device 10 is removable from the mask 2 by tearing the device 10 away from the outside surface 3 of the mask 2. The device 10 can then be recharged if necessary and attached to a new face mask and/or a face shield.

[0066] Figures 6 to 8 illustrate another exemplary embodiment of a voice amplification device 110. This embodiment is similar to the embodiment of the device 10 of Figures 2 to 5 and like reference numerals will be used to identify like components.

[0067] A difference in the voice amplification device 110 of Figures 6 and 7 is that the voice detection module and the voice reproduction module housed in separate housings, namely a voice detection module housing 115 and a voice reproduction module housing 118. Furthermore, the voice detection module and the voice reproduction module are wirelessly connected which means each housing 115, 118 can be separate, individual components.

[0068] The voice detection module further includes a first coil 116 located at an intermediate end 126 of the voice detection module housing 115. The voice reproduction module includes a second coil 119 located at an intermediate end 128 of the voice reproduction module housing 118. The first coil 116 is adapted to transmit a signal that is received by the second coil 119. The coils 116, 119 are adapted to transmit and receive signals by an inductive coupling. The inductive coupling between the two nearby coils or loop antennas forms an air- core transformer. A control circuit is provided to control the wireless signal transmission through the inductive loop coupling via the near-field communication (NFC) protocol.

[0069] In addition or alternatively, the voice detection module and the voice reproduction module are configured to transmit data using UHF radio waves. In this embodiment, instead of the coils 116, 119 the voice detection module and the voice reproduction module include either or both a transmitter and a receiver adapted to transmit and receive UHF radio signals and associated control circuitry to encode and decode signals. An example of a wireless UHF radio wave data transmission protocol includes the Wi-Fi and/or the Bluetooth protocol.

[0070] Signals may be transmitted wirelessly between the analogue-to-digital converter 30 on-board the voice detection module housing 115 and the digital signal processor 40 on-board the voice reproduction module housing 118. The signal received by the second coil 119 is passed to the digital signal processor 40 and to a digital-to-analogue converter and on to the audio power amplifier 50. The audio power amplifier 50 provides a signal to drive the loudspeaker 60 which in turn generates a corresponding acoustic.

[0071] As illustrated in Figure 6, the intermediate ends 126, 128 of the housings 115, 118 include one or more permanent magnets 129. The magnets 129 are adapted to impart an attractive force to retain the housings 115, 118 together on opposite sides of a continuous barrier, such as the outside surface 3 of the mask 2 as illustrated in Figure 8. The magnets 129 are configured to locate the first and second coils 116, 119 in alignment with each other to facilitate an inductive coupling therebetween.

[0072] Accordingly, Figure 8 illustrates an exemplary application of the device 110 of Figures 6 and 7 wherein, in use, the voice detection module housing 115 is located inside the respirator mask 2 or face shield and the voice reproduction module housing 118 is located outside the face mask 2. The device 110 does not require any penetration of the face mask 2 and can be used with any type of face mask or face shield or other continuous barrier.

[0073] Figures 9 and 10 illustrate another exemplary embodiment of the voice amplification device 210. This embodiment is similar to the embodiment of the device 10 of Figures 2 to 5 and like reference numerals will be used to identify like components. [0074] A difference in the voice amplification device 210 of Figures 9 and 10 is that the voice detection module and the voice reproduction module are wire connected wherein at least part of the voice detection module, including at least the microphone 20, is on the end of a thin clip 214 that hooks around the edge of the outside surface 3 of the mask 2. Accordingly, the microphone 20 is on the inside of the face mask 3 and/or face shield and the voice reproduction module is on the outside of the face mask 3.

[0075] Figure 10 illustrates an exemplary application of the device 210 of Figure 9 wherein, in use, at least the microphone 20 of the voice detection module is attached inside the face mask with wires connecting the microphone 20 to the analogue-to-digital converter 30 on-board the housing 12.

[0076] Similar to the other embodiments, the microphone transducer 20 functions to pick up sound and then converts the sound into an electrical signal. The analogue-to-digital converter 30 converts the amplified analogue input signal to a digital output signal. The digital signal processor 40 receives and processes the digital output signal which in turn is provided to a digital-to- analogue converter that converts the processed digital output signal to an analogue output signal. The analogue output signal is provided to the audio power amplifier 50 that amplifies the analogue output signal to drive the loudspeaker 60 which in turn can generates a corresponding acoustic output. The loudspeaker 60 is housed within the housing 12 attached on the outside surface 3 of the face mask 2.

[0077] The clip 214 is preferably formed out of a resiliently flexible material such as metal wire, preferably U-shaped, and preferably has a soft and flexible covering to provide smooth interface between the wearer’s skin and an edge 6 of the outside surface 3 of the mask 2 to minimise any potential interference with the seal between the mask and the wearer’s face. Although in Figure 10 the device 210 is mounted so that the clip 214 enters the inside of the mask 2 near a face strap 8 mount location near the wearer’s nose, it is to be appreciated that the device 210 may be mounted towards the bottom of the mask 2 where the clip 214 can enter inside the mask 2 from underneath. [0078] In another embodiment, not illustrated in the Figures, the device comprises two components, such a first housing containing the voice detection module or at least the microphone component thereof, and a second housing containing the remaining components of the voice detection and reproduction modules. The first and second housings are separately interconnected by a pin that is configured to penetrate through the barrier 3 of the mask 2. The pin includes wires for connecting at least the microphone component of the device with the remaining components of the device.

[0079] Similar to the other embodiments, the microphone transducer functions to pick up sound and then converts the sound into an electrical signal. In an embodiment, the signal is transmitted through a wire incorporated in the pin to the analogue-to-digital converter that is mounted within the main housing of the device mounted to the exterior of the barrier 3 of the mask 2. The digital-to- analogue converter converts the analogue input signal to a digital output signal. Alternatively, the digital output signal may be transmitted through a wire incorporated in the pin to the digital signal processor 40 which is incorporated in the main housing located on the exterior of the mask 2. The digital output signal is processed and is provided to a digital-to-analogue converter that converts the processed digital output signal to an analogue output signal. The analogue output signal is provided to the audio power amplifier that amplifies the analogue output signal to drive the loudspeaker which in turn can generates a corresponding acoustic output. The loudspeaker is also housed within the main housing attached on the outside surface 3 of the face mask 2.

[0080] In Figures 5, 8 and 10, the embodiments of the device 10, 110 and 210 are mounted to the mask 2 near a face strap 8 mount location near the wearer’s nose. However, it is to be appreciated that each embodiment of the device 10, 110 and 210 may be mounted towards the bottom of the mask or at another suitable location on the mask according to user preference, comfort and practical application. Location of each embodiment of the device 10, 110 and 210 on the mask 2 may also be dependent upon the type of mask or face shield and where there is available space on the outside surface 3 of the face mask 2 for the device 10, 110 and 210. [0081] Figures 11 and 12 illustrate another embodiment of the device 310. A schematic representation of the device 310 is illustrated in Figure 11 including a first housing 111 adapted to be located on the inside of the mask 2 and a second housing 114 is adapted to be located on the outside surface 3 of the mask 2. The microphone transducer 120 is mounted in the first housing 111 and is adapted to pick up sound and then converts the sound into an electrical signal. The electrical signal is received by volume control and preamplifier module 130 within the first housing 111 for increasing the signal voltage.

[0082] A clip 215 is formed out of a resiliently flexible material such as metal wire, preferably U-shaped, connects the first housing 111 to the second housing 114. The clip 215 also includes a conductor for conducting the signal from the preamplifier module 130 to a high pass filter 135 within the second housing 114. The high pass filter 135 eliminates low frequencies in the signal below about 300 Hz. The signal is then received in an audio power amplifier 140 that amplifies the analogue output signal. The amplified analogue output signal is passed through a low pass filter 150 for eliminating frequencies in the signal above about 3400Hz before being received by the loudspeaker 160 which in turn generates a corresponding acoustic output.

[0083] The high pass filter 135 and the low pass filter 150 together operate as a bandpass filter to permit frequencies in the range of about 300 to 3400 Hz, that is the range of the human voice, to be reproduced by the loudspeaker 60.

[0084] The device 310 preferably has a USB-C port for charging and includes a rechargeable battery, such as a Li-ion battery, a charging circuit and an audio amplifier on/off switch. As part of the battery charging circuit, there is also a temperature sensor to ensure the battery is only charged when within ideal temperature ranges.

[0085] The microphone 120 is preferably comprised of a condenser microphone and the speaker 160 preferably has a power rating of 1 Watt and an impedance of 8 Ohms. In other embodiments, the speaker 160 can have an impedance of 4 ohms. [0086] The first housing 111 and the second housing 114 are preferably similar in form to the voice detection module housing 115 and the voice reproduction module housing 118 of Figure 8. In particular, the first housing 111 and the second housing 114 include a magnet for so they can attach together when put onto a mask.

[0087] In an embodiment, the first housing 111 located on the inside of the mask includes a microphone 120 and magnet only. The second housing 114 located on the outside of the mask includes a circuit board including the volume control and preamplifier module 130, the high and low pass filters 135, 150, the power amplifier 140, a battery, on/off switch and the speaker 160.

[0088] Figures 13 and 14 illustrate another embodiment of the device 310 which is similar to the embodiment of Figures 11 and 12 and so like reference numerals are used to identify like features. In the embodiment of Figures 13 and 14, the first housing 111 is adapted to be located on the inside of the mask 2 and the second housing 114 is adapted to be located on the outside surface 3 of the mask 2.

[0089] The first housing 111 includes one or more permanent magnets 129 and the second housing 114 also includes one or more permanent magnets 129. The magnets 129 are adapted to impart an attractive force to retain the housings 111, 114 together on opposite sides of a continuous barrier, such as on opposite sides of the outside surface 3 of the mask 2 as illustrated in Figure 14.

[0090] The clip 215 is not required to physically retain the housings 111 , 114 together on opposite sides of the outside surface 3 of the mask 2 as this task is performed by the magnets 129. Instead, the clip 215 may be a comprised of a relatively flexible wire for electrical and signal conduction between the first housing 111 and the second housing 114. In particular, the clip 215 conducts the signal from the voice detection module housing 115 and the voice reproduction module housing 118. [0091] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms, in keeping with the broad principles and the spirit of the disclosure described herein.

Claims

Claims:

1. A voice transmission device for transmitting a voice on one side of a barrier, such as a face mask or other barrier, to another side of the barrier, the device including: a voice detection module for picking up a voice on one side of the barrier; and a voice reproduction module for reproducing the voice on the other side of the barrier.

2. The voice amplification device of claim 1 , wherein the voice detection module and the voice reproduction module are contained in an integral housing for attachment to one side of the barrier.

3. The voice amplification device of claim 2, wherein the housing is configured to be attached to a side of the barrier opposite to the source of the voice.

4. The voice amplification device of claim 1 , wherein the voice detection module is contained in a first housing attached to a side of the barrier the same as the source of the voice and the voice reproduction module is contained in a second housing attached to a side of the barrier opposite to the source of the voice.

5. The voice amplification device of claim 4, wherein the voice detection module is adapted to convert the sound of the voice into a signal that is transmitted wirelessly to the voice reproduction module.

6. The voice amplification device of claim 5, wherein the voice detection module includes a first coil for transmitting the signal and the voice reproduction module includes a second coil for receiving the signal.

7. The voice amplification device of any one of claims 4 to 6, wherein the voice detection module and the voice reproduction module comprise one or more magnets to retain the modules together on either side of the barrier.

8. The voice amplification device of claim 4, wherein the voice detection module and the voice reproduction module are interconnected by a wire.

9. The voice amplification device of claim 8, wherein the voice detection module is adapted to convert the sound of the voice into a signal that is transmitted through the wire to the voice reproduction module.

10. The voice amplification device of claim 8 or claim 9, wherein the voice detection module is mounted on the end of a clip that is adapted to be mounted at an edge of the barrier.

11. The voice amplification device of claim 4, wherein the voice detection module and the voice reproduction module are interconnected by a pin that penetrates through the barrier.

12. The voice amplification device of claim 11, wherein the voice detection module is adapted to convert the sound of the voice into a signal that is transmitted through the pin to the voice reproduction module.

13. The voice amplification device of claim 1, wherein the voice detection module includes a microphone transducer that generates an output signal that is provided to the voice reproduction module as an input for reproducing the voice.

14. The voice amplification device of claim 13, wherein the microphone transducer comprises a micro-electromechanical system (MEMS) transducer.

15. The voice amplification device of claim 13, further including a digital signal processor for receiving the output signal and isolating any unwanted noise to provide a clearer signal representing the voice.

16. The voice amplification device of claim 15, further including a digital-to- analogue converter that converts an output signal from the digital signal processor to an analogue output signal.

17. The voice amplification device of claim 13, wherein the device includes an analogue amplification circuit including an analogue preamplifier and volume control and one or more analogue filters.

18. The voice amplification device of claim 17, wherein the analogue filters include a low pass filter and/or a high pass filter, wherein the low pass filter is configured to eliminate frequencies above about 3400Hz and the high pass filter is configured to eliminate low frequencies below about 300 Hz.

19. The voice amplification device of claim 16, wherein the voice reproduction module includes an audio power amplifier that amplifies the analogue output signal.

20. The voice amplification device of claim 19, wherein the voice reproduction module includes a loudspeaker transducer that receives the amplified output signal from the amplifier to reproduce the voice detected by the microphone transducer.

21. The voice amplification device of claim 1, including a voice activated switch or a capacitance switch activated by touch to activate the voice transmission device.

22. The voice amplification device of claim 1 , wherein the device further comprises a battery that is rechargeable through a micro-USB cable or a wireless inductive coupling with a charging station.