TECHNICAL FIELD

This invention relates to a monitoring device. In particular, this invention relates to a monitoring device for monitoring exposure of a user to sound and for indicating when a predetermined level of exposure has been reached.

SUMMARY OF THE INVENTION

According to the invention there is provided a monitoring device for monitoring exposure to sound, wherein the monitoring device includes: - an ear engaging member which is shaped, sized and/or configured to engage and span an opening to an ear canal; a sound transmitter which is configured to transmit sound via the ear engaging member into the ear canal, when in use; and a sound sensor which is configured to sense the sound transmitted into the ear canal via the sound transmitter.

The device may include a sound sensor transmitter which is configured to transmit information relating to sound sensed by the sound sensor to a processor.

The ear engaging member may include an insert portion which is configured to be inserted complementally, preferably in friction fit engagement, with a wall defining the ear canal inwardly the opening of the ear canal. The insert portion may have a free end region which, when in use, faces/extends into the ear canal. More specifically, the insert portion may be of generally tubular form which may taper towards a free end region thereof.

Communication passage(s) may be defined in the insert portion for allowing communication, preferably sound communication, between the sound transmitter and the ear canal and between the sound sensor and the ear canal respectively.

The monitoring device may include a sealing member which extends outwardly from the free end region of the insert portion (i.e. towards the wall of the ear canal) to encourage snug sealing engagement between the insert portion and the ear canal to ensure that the sound transmitted into the ear canal remains within the ear canal. The sealing member may have a generally wedge-shaped sectional profile, the wedge preferably tapering towards the free end region of the insert. The sealing member may be formed integrally with the insert portion. A further sealing member may extend outwardly the insert portion in a region opposite the free end region thereof.

Alternatively, the sealing member may include a sleeve portion which may be received co-axially and removably the insert portion and a substantially wedge and/or cup-shaped flange, preferably having three wedge and/or cup-shaped flanges, extending from the sleeve portion for allowing snug sealing engagement between the insert portion and inner walls of the ear canal.

The insert portion may have a generally tubular form which defines a longitudinal axis. The sealing member may then include: a sleeve portion which is received co-axially with, and is removably secured to, the insert portion; and

a substantially wedge/cup shaped flange which extends from the sleeve portion for allowing snug sealing engagement between the insert portion and the inner wall of the ear canal.

The flanges and/or sleeve portion may be sized, shaped and/or configured so as to facilitate retention of the ear engaging member in the engaged condition. In particular, the flanges and/or sleeve portion may be customised according to a particular user's ear. The sealing member may be manufactured from rubber or silicone.

The ear engaging member may include a housing portion for housing the sound transmitter, sound sensor and the sound sensor transmitter. The housing portion may extend from the insert portion. The housing portion may include a closure member, preferably in the form of a cap, for closing off an access opening of the housing portion to inhibit access to and/or the ingress of fluid to protect the sound transmitter, sound sensor and sound sensor transmitter. The sound transmitter may be in the form of an earphone loudspeaker driver, preferably any conventional earphone loudspeaker driver, for transmitting sound. The earphone loudspeaker driver may be selected from any driver of the group including dynamic/dynamical, armature, balanced armature, planar magnetic, electrostatic and magnetostriction or bone conduction driver. The drive may preferably be in the form of a balanced armature driver.

The sound sensor may include, or be in the form of, a pressure sensor, typically in the form of a diaphragm arrangement, for sensing pressure in the ear canal. The pressure sensor may be configured to sense pressure as a result of sound caused by various functions taking place in the human body, when in use. In particular, the pressure sensor may be configured to sense pressure as a result of sound caused by a beating heart and/or by respiration. The sound sensor may include a transducer for converting information received from the pressure sensor into a signal, preferably an electrical signal, before being transmitted by the sound sensor transmitter to the processor. The sound sensor may be in the form of any suitable conventional microphone of the group including a dynamic or moving-coil microphone, moving-ribbon microphone, a condenser microphone and an electret condenser microphone preferably being an electret condenser microphone. It is to be appreciated that the sound sensor may be calibrated according to anatomical characteristics of a particular user's canal to allow user-specific calibrated hearing testing, preferably by means of air conduction audiometry.

The sound sensor transmitter may include a wired and/or wireless transmitting arrangement for transmitting the information relating to sound sensed by the sound sensor to the processor. The wireless transmitting arrangement may be configured to transmit the information via electromagnetic radiation having any frequency in the range of 2GHz to 6GHz typically defined by Bluetooth and/or Wi-Fi.

For the purposes of this specification, the term "spectral leakage", a type of distortion, is to be understood as a term describing the presence of unwanted spectral components usually found at higher frequencies after a Fourier transform is performed on time based data. Further, the term "window function" is to be understood as a mathematical function, typically time-based, which is often used in signal processing to prevent the occurrence of distortion or spectral leakage. This function multiplies the signal by values at or near zero, near the beginning and end of the time window and weights them at or near 1 , near the middle of the time window. The result is that the effect of spectral leakage is minimized when the Fourier transform is applied. In addition, the term "pulse-code modulation audio buffer" is to be understood as a standard form of digital audio on computers, compact discs, digital telephony and the like.

The processor may form part of the monitoring device.

The monitoring device may include a processor (hereinafter referred to as the "internal processor") which is operatively/communicatively connected to the sound sensor in order to receive data/information on sound sensed by the sound sensor.

The internal processor may be configured to carry out the following steps to process the data/information received from the sound sensor to determine a quantity of sound being exposed to a user over a particular time interval, the steps including: - calculating a quantity of sound to which the user is exposed over the particular time interval by utilising the data/information; and comparing the quantity of sound to a predetermined safe quantity of sound exposure to determine if the safe quantity of sound exposure has been reached.

More specifically, the internal processor may be configured to carry out the following step to process the data/information received from the sound sensor to determine a quantity of sound being exposed to a user over a particular time interval, wherein the step includes: - recording the data/information received from the sound sensor over a smaller time interval, the recording typically being in the form of a buffer/sample.

The internal processor may be further configured to carry out the following step: converting the electrical signals in the buffer/sample into amplitude and frequency information over time.

More specifically, the internal processor may be configured to carry out the following steps to process the data/information received from the sound sensor to determine a quantity of sound, preferably measured in decibels (dB), being exposed to a user over a particular time interval (hereinafter referred to as the "particular time interval"), the steps including: - a) recording the data/information received from the sound sensor over a smaller time interval (hereinafter referred to as the "smaller time interval"), the recording typically being in the form of a buffer/sample; b) converting the electrical signals in the buffer/sample into amplitude and frequency information over time; c) proportioning, multiplying or filtering the amplitude and frequency information over time so as to remove higher frequency energy from the buffer/sample; d) converting the proportioned, multiplied or filtered amplitude and frequency information over time into amplitude per frequency information; e) grouping the amplitude per frequency information according to frequency ranges into respective bins; f) combining the amplitude per frequency information in each bin to provide a single decibel value for each bin; g) converting the amplitude per frequency information into decibel values per bin; h) weighting the decibel values in each bin according to an effect of frequency on the human ear; i) weighting the decibel values in each bin according to a sensitivity of the sound sensor as determined through a prior calibration process; j) weighting the decibel values in each bin according to unique acoustic characteristics of the ear engaging member; k) summing the weighted decibel values (i.e. the weighted values of steps (h) to (j)) of each bin in a buffer to obtain a single decibel value for the buffer to determine a user's current listening level;

I) recording a plurality of buffers which are combined to provide the quantity of sound to which the user is exposed over the particular time interval; and m) comparing the quantity of sound to a predetermined safe quantity of sound exposure to determine if the safe quantity of sound exposure has been reached.

The term "acoustic characteristics" refers to the positioning of the sound sensor in relation to the sound transmitter and the positioning of the sound sensor (inside the ear engaging member) in relation to a corresponding tympanic membrane of a person, when using the monitoring device. The unique characteristics may include : a length of the insert portion of the ear engaging member; a size of an ear tip(s) that may be attached to the insert portion of the ear engaging member; and/or the flange(s) of the the sealing member.

The internal processor may be configured to perform any one or more of the above- listed steps ((a)-(m)), for example, only steps (a)-(c) or steps (a)-(d).

According to a second aspect of the invention, there is provided a monitoring system for monitoring exposure to sound wherein the monitoring system includes: the monitoring device in accordance with the first aspect of the invention; and a processor which is communicatively connected to the monitoring device. The system may include a computing device which includes/incorporates the processor. In other words, the processor may be incorporated in a computing device. The computing device may be a computer or smart device, such as a smart phone or smart watch. The processor may therefore be in the form of any suitable device capable of processing electrical signals sensed by the sound sensor (such as a computer, mobile phone or watch).

The monitoring device may include a sound sensor transmitter which is configured to transmit information relating to sound sensed by the sound sensor to the processor.

The processor may be configured to carry out the following steps to process data/information captured by the sound sensor to determine a quantity of sound being exposed to a user over a particular time interval (hereinafter referred to as the "particular time interval"), the steps including: - calculating a quantity of sound to which the user is exposed over the particular time interval by utilising the data/information; and comparing the quantity of sound to a predetermined safe quantity of sound exposure to determine if the safe quantity of sound exposure has been reached.

The information transmitted to the processor may be in the form of electrical signals. The processor may be configured to carry out the following steps to process the electrical signals received from the sound sensor to determine a quantity of sound, preferably measured in decibels (dB), being exposed to a user over a particular time interval (hereinafter referred to as the "particular time interval"), the steps including: - recording the information received from the sound sensor over a smaller time interval (hereinafter referred to as the "smaller time interval"), the recording typically being in the form of a buffer/sample; converting the electrical signals in the buffer/sample into amplitude and frequency information over time; proportioning, multiplying or filtering the amplitude and frequency information over time so as to remove higher frequency energy from the buffer/sample; converting the proportioned, multiplied or filtered amplitude and frequency information over time into amplitude per frequency information; grouping the amplitude per frequency information according to frequency ranges into respective bins; combining the amplitude per frequency information in each bin to provide a single decibel value for each bin; converting the amplitude per frequency information into decibel values per bin; weighting the decibel values in each bin according to an effect of frequency on the human ear; weighting the decibel values in each bin according to a sensitivity of the sound sensor as determined through a prior calibration process; weighting the decibel values in each bin according to unique acoustic characteristics of the ear engaging member summing the weighted decibel values of each bin in a buffer to obtain a single decibel value for the buffer to determine a user's current listening level; recording a plurality of buffers which are combined to provide the quantity of sound to which the user is exposed over the particular time interval; and comparing the quantity of sound to a predetermined safe quantity of sound exposure to determine if the safe quantity of sound exposure has been reached.

The particular time interval may be any desired time interval in the range of 30 minutes to 1 year, preferably between 30 minutes and 1 month, more preferably between 1 hour and 2 days, ideally 1 day. The particular time interval may therefore be any desired time interval of the group including an hour, day, week, month and a year, preferably being a day. The smaller time interval may be any desired time interval in the range 0.05 seconds to 5 seconds, preferably being 1 second. The buffer may be in the form of a 16-bit pulse-code modulation audio buffer.

The amplitude and frequency data in the buffer may be proportioned, multiplied or filtered over time, by the processor, so as to remove higher frequency energy from the buffer in order to minimise distortion, typically as a result of spectral leakage. The proportioning, multiplying or filtering may be carried out using any suitable window function of the group including a rectangular and/or hamming window function, preferably being a hamming window function.

The proportioned, multiplied or filtered amplitude and frequency information over time may be converted into amplitude per frequency information using any suitable mathematical method, preferably a fast Fourier transform.

The amplitude per frequency information may be grouped into the respective bins according to octave bands. For the purposes of this specification, the term "A-weighting" is to be understood as a technique which is used in an attempt to account for relative loudness perceived by a human ear when measuring sound levels with a sound measuring instrument.

The decibel values in each bin may be weighted according to an effect of frequency on the human ear using a technique known as A-weighting which provides an "A- weighted" decibel value (dBA).

The safe quantity of sound may correspond to any suitable international standards relating to sound and/or noise, preferably relating to recreational sound, such as standards set by the International Telecommunication Union (ITU) and/or the World Health Organization (WHO). The safe quantity of sound may be in the range of 75dB to 90dB, preferably being 80dBA, over a period of 8 hours.

The plurality of buffers recorded may be combined to provide the quantity of sound to which the user is exposed over the particular time interval according to the following mathematical formula:

quantity of sound = 100 x {^7 + C ₂ T ₂ +— h C _n T _n }, where

C ₂ = time spent at each noise level

82(L - 25)

T _n = , where

L = current listening level in dBA

An alerting means may be provided for alerting a user when the quantity of sound to which the user is exposed exceeds the predetermined safe quantity of sound. The alerting means may be in the form of a notification from an application for a mobile device. The alerting means may therefore form part of the monitoring system.

It is to be appreciated that the monitoring device may facilitate telecommunications between a user and a third party via a cellular mobile device to which the monitoring device may be connected. The monitoring system may include a calibrator device for calibrating sensitivity of the sound sensor of the monitoring device (and preferably sound output of the processor), the calibrator device including: a body which defines a chamber having an opening for receiving a portion of the monitoring device therein; and a sound generator mounted on the body for generating a sound inside the chamber to be sensed by the sound sensor of the monitoring device.

The ear engaging member may include an insert portion which is configured to be inserted complementally with a wall defining the ear canal inwardly the opening of the ear canal. The opening of the chamber may be located at one end of the tubular chamber and may be sized and/or shaped so as to allow snug sealing engagement between the insert portion of the monitoring device and inner walls of the chamber, when the calibrator device is used for calibrating the sensitivity of the sound sensor of the monitoring device. The sound generator may be configured to generate a predetermined sound inside the chamber to be sensed by the sound sensor and transmitted to the processor to be stored as a reference sound, when the insert portion thereof is received by the opening of the chamber.

According to a third aspect of the invention, there is provided a calibrator device for calibrating sensitivity of a sound sensor of a monitoring device and sound output of a processor, the calibrator device including: - a body which defines a chamber having an opening for receiving a portion of the monitoring device therein; and a sound generator mounted on the body for generating a sound inside the chamber to be sensed by a sound sensor of the monitoring device.

The monitoring device may be the monitoring device according to the first aspect of the invention.

The body may be of generally tubular form which may define a substantially tubular chamber. Walls of the body may have a thickness in the range of 5mm to 10mm, preferably being 6.25mm. The chamber may be sized, shaped and/or configured to imitate anatomical characteristics of a human ear canal. The opening may be located at one end of the tubular chamber and may be sized and/or shaped so as to allow snug sealing engagement between the insert portion of the monitoring device and inner walls of the chamber. The opening may have a diameter in the range of 5mm to 15mm, preferably being 9.5mm.

The sound generator may be located at an opposing end of the tubular chamber. The sound generator may generate a predetermined sound inside the chamber to be sensed by the sound sensor and transmitted to the processor to be stored as a reference sound when the insert portion thereof is received by the opening of the chamber. The predetermined sound may be in the form of any one or more of the group including white noise, preferably having frequencies in the range of 31 Hz to 16kHz, brown noise, pink noise, grey noise and a sound having unique tone characteristics. The sound transmitter of the monitoring device may then transmit the reference sound into the chamber to be sensed by the sound sensor as a sensed reference sound. The processor may then compare the sensed reference sound to a transmitted reference sound to determine a difference therebetween, which difference may represent a deviation in actual sound output of the processor. The deviation in sound output of the processor may be stored in the processor as a sealed cavity offset in order to account therefore during the monitoring of sound exposure to a user.

It is to be appreciated that the monitoring device may be further calibrated according to anatomical characteristics of a particular user's ear canal. The processor of the monitoring device may determine a difference between sound transmitted into the ear canal and sensed by the sound sensor when the insert portion is received by the opening of the user's ear canal and incorporating the sealed cavity offset, which difference may represent a deviation caused by the anatomical characteristics of the particular user's ear canal. The deviation may be stored in the processor of the monitoring device as a sealed ear canal offset.

It is further to be appreciated that the processor may determine the quality of the seal formed between the insert portion of the monitoring device and the walls of the chamber and/or the ear canal by comparing the sound transmitted into the chamber or ear canal to the sound sensed by the sound sensor incorporating both the sealed cavity and sealed ear canal offsets so as to determine a difference therebetween, wherein a difference exceeding a predetermined level in the range of 1 dB to 10dB, preferably 3dB, may indicate that an insufficient seal is formed.

An energising means may be provided for energising the sound generator in use. The energising means may be in the form of a battery. Alternatively, the energising means may be in the form of a USB power supply arrangement which may include a USB port located on the body and may be in electrical communication with the sound generator for receiving power via any suitable USB cable which may be connected to an external power supply in use.

BRIEF DESCRIPTION OF THE DRAWINGS

A monitoring device in accordance with the invention will now be described by way of the following, non-limiting examples with reference to the accompanying drawings.

In the drawings: -

Figures 1 and 2 are three-dimensional schematics showing generally front and rear views, respectively, of a portion of an ear engaging member of a monitoring device in accordance with the invention; Figure 3 is a three-dimensional schematic showing a generally rear view of the ear engaging member shown in Figures 1 and 2 including a closure member

Figure 3 is a sectioned side view of the ear engaging member as shown in Figures 1 and 2;

Figure 5 is a partially transparent side view of the ear engaging member showing a sound transmitter housed therein;

Figure 6 is a partially transparent side view of the ear engaging member showing a sound transmitter and a sound sensor housed therein;

Figure 7 is a three-dimensional schematic showing the monitoring device in accordance with the invention; Figure 8 is a three-dimensional schematic showing the sound sensor as shown in Figures 6 and 7;

Figure 9 is a side view of the sound sensor shown in Figure 8;

Figure 10 is a side view of the sound transmitter as shown in Figures 5 to 7; Figures 1 1 and 12 are sectioned side views of the monitoring device in a disengaged and an engaged condition, respectively;

Figure 13 is a three-dimensional schematic of the calibrator device in accordance with a second aspect of the invention;

Figure 14 is a sectioned side view of the calibrator device as shown in Figure 13; and

Figure 15 is a schematic layout of a monitoring system in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, reference numeral 10 refers generally to a monitoring device in accordance with the invention. The monitoring device 10 includes an ear engaging member 12 which is shaped, sized and configured to engage and span an opening 14 to an ear canal 16, a sound transmitter 18 for transmitting sound via the ear engaging member 12 into the ear canal 16, a sound sensor 20 for sensing sound in the ear canal 16 and a sound sensor transmitter (not shown) for transmitting information relating to sound sensed by the sound sensor 20 to a processor 24. The monitoring device 10 and the processor 24 may form part of a monitoring system 100 in accordance with the invention. In this regard, reference is made to Figure 15. In the example illustrated in Figure 15, the processor 24 is incorporated into a smart phone 102. It will however be appreciated that the processor 24 could form part of any other computing device, such as a smart watch or computer. Furthermore, the system 10 may include two (or more) processors. In this regard, the system can include the processor 24 as well as a processor which is incorporated into/forms part of the monitoring device 10 (hereinafter referred to as the "internal processor"). It should therefore be noted that the processing steps described below may be implemented by the processor 24, the internal processor of the monitoring device 10, or a combination of both. In other words, some of the processing steps may be performed by the internal processor, while the processor 24 performs the other/remaining steps. The ear engaging member 12 includes an insert portion 26 which is configured to be inserted complementally, in friction fit engagement, with a wall 28 defining the ear canal 16 inwardly the opening 14 of the ear canal 16. The insert portion 26 is of generally tubular form which tapers towards a free end region 30 thereof.

Communication passages 32 are defined in the insert portion 26 for allowing sound communication between the sound transmitter 18 and the ear canal 16 and between the sound sensor 20 and the ear canal 16 respectively.

A sealing member 34 extends outwardly the free end region 30 of the insert portion 26 to encourage snug sealing engagement between the insert portion 26 and the ear canal 16 to ensure that the sound transmitted into the ear canal 16 remains within the ear canal 16. The sealing member 34 has a generally wedge-shaped sectional profile, the wedge tapering towards the free end region 30 of the insert portion 26. The sealing member 34 is formed integrally the insert portion 26, as shown in Figures 1 to 3 and 5 to 7.

Alternatively, as shown in Figures 4, 10 and 1 1 , the sealing member 34 includes a sleeve portion 38 which is received co-axially and removably the insert portion 26 and a substantially cup-shaped flange 40 extending from the sleeve portion 38 for allowing snug sealing engagement between the insert portion 26 and inner walls 28 of the ear canal 16. More particularly and as shown in Figures 10 and 1 1 , the sealing member 34 includes three substantially cup-shaped flanges 40. The flanges 40 and sleeve portion 38 are sized, shaped and configured so as to facilitate retention of the ear engaging member 12 in the engaged condition. In particular, the flanges 40 and sleeve 38 portion are customised according to a particular user's ear. The sealing member 34 is manufactured from silicone.

The ear engaging member 12 includes a housing portion 42 for housing the sound transmitter 18, sound sensor 20 and the sound sensor transmitter (not shown). The housing portion 42 extends from the insert portion 26. The housing portion 42 includes a closure member in the form of a cap 44 for closing off an access opening 46 of the housing portion to inhibit access to and ingress of fluid to protect the sound transmitter 18, sound sensor 20 and sound sensor transmitter (not shown).

The sound transmitter 18 is in the form of an earphone loudspeaker driver for transmitting sound. The earphone loudspeaker driver is selected from a driver of the group including a dynamic/dynamical, armature, balanced armature, planar magnetic, electrostatic and a magnetostriction or bone conduction driver. In the preferred embodiment, the earphone loudspeaker driver is in the form of a balanced armature driver 48.

The sound sensor 20 is in the form of a pressure sensor, typically in the form of a diaphragm arrangement (not shown), for sensing pressure in the ear canal. The pressure sensor is configured to sense pressure as a result of sound caused by various functions taking place in the human body. In particular, the pressure sensor is configured to sense pressure as a result of sound caused by a beating heart and by respiration. The sound sensor includes a transducer (not shown) for converting information from the diaphragm arrangement into an electrical signal before being transmitted by the sound sensor transmitter to the processor 24. The sound sensor is in the form of a conventional electret condenser microphone 50. It is to be appreciated that the sound sensor is calibrated according to anatomical characteristics of a particular user's canal to allow user-specific calibrated hearing testing by means of air conduction audiometry.

The sound sensor transmitter (not shown) includes a wireless transmitting arrangement (not shown) for transmitting the information relating to sound sensed by the sound sensor 20 to the processor 24. The wireless transmitting arrangement (not shown) transmits the information relating to sound via electromagnetic radiation having a frequency of 2.4GHz, typically defined by Bluetooth.

The processor 24 is in the form of a device capable of processing electrical signals received by the sound sensor, such as a computer, mobile phone or watch. The processor 24 carries out the following steps to process the electrical signals received from the sound sensor to determine a quantity of sound measured in decibels, being exposed to a user over a particular time interval of one day, the steps including: - a) recording the electrical signals received by the sound sensor over a smaller time interval of 1 second, the recording typically being in the form of a 16-bit pulse-code modulation (PCM) audio buffer/sample; b) converting the electrical signals in the buffer/sample into amplitude and frequency information over time; c) proportioning, multiplying or filtering the amplitude and frequency information over time so as to remove higher frequency energy from the buffer/sample thereby minimising distortion as a result of spectral leakage, the proportioning typically being carried out using a hamming window function; d) converting the proportioned, multiplied or filtered amplitude and frequency information into amplitude per frequency information using a fast Fourier transform; e) grouping the amplitude per frequency information according to frequency in octave bands into respective bins; f) combining the amplitude per frequency information in each bin to provide a single decibel value for each bin; g) converting the amplitude per frequency information into decibel values per bin; h) weighting the decibel values in each bin according to an effect of frequency on the human ear using a technique known as A-weighting which provides an "A-weighted" decibel value (dBA); i) weighting the decibel values in each bin according to the sensitivity of the sound sensor as determined through the calibration process; j) weighting the decibel values in each bin according to the unique acoustic characteristics of the ear engaging member; k) summing the weighted decibel values of each bin in a buffer to obtain a single decibel value for the buffer to determine a user's current listening level in dBA which represents total sound energy contained in the 16-bit PCM audio buffer; I) recording a plurality of 16-bit PCM audio buffers which are combined to provide the quantity of sound to which the user is exposed over the particular time interval of one day; and m) comparing the quantity of sound to a predetermined safe quantity of sound, typically being 85dBA over a period of 8 hours, to determine if the safe quantity of sound exposure has been reached.

The safe quantity of sound corresponds to suitable international standards relating to sound and/or noise, such as standards set by the International Organization of Standardization (ISO) and/or World Health Organization. As mentioned earlier, it should be appreciated that the monitoring device 10 can include an internal processor which is configured to perform any one or more of the processing steps (a) to (m) described above. In one example, the internal processor could implement all the processing steps ((a)-(m)). In another example, the internal processor could perform some of the processing steps (e.g. steps (a) and (b)) and then send this processed information to the processor 24 which performs the rest of the processing steps (e.g. steps (c)-(m)).

The plurality of 16-bit PCM audio buffers are combined to provide the quantity of sound over the particular time interval according to the following mathematical formula: quantity of sound = 100 x {^7 + C ₂ T ₂ +— h C _n T _n }, where

C ₂ = time spent at each noise level

82(L - 25)

T _n = , where

L = current listening level in dBA An alerting means in the form of a notification from an application for a mobile device (not shown) is provided for alerting a user when the quantity of sound to which the user is exposed exceeds the predetermined safe quantity of sound.

It is to be appreciated that the monitoring device facilitates telecommunications between a user and a third party via a cellular mobile device to which the monitoring device is connected. Referring now to Figures 13 and 14 reference numeral 52 refers generally to a calibrator device for calibrating sensitivity of a sound sensor of a monitoring device and sound output of a processor 24, the calibrator device 52 including a body 54 which defines a chamber 56 having an opening 58 for receiving a portion of the monitoring device 10 therein and a sound generator 60 mounted on the body for generating a sound inside the chamber 56 to be sensed by a sound sensor 20 of the monitoring device 10. As shown in Figure 15, then calibrator device 52 can form part of the monitoring system 100.

The body 54 is of generally tubular form which defines a substantially tubular chamber 56. Walls 62 of the body 54 have a thickness of 6.25mm. The chamber 56 is sized, shaped and configured to imitate anatomical characteristics of a human ear canal. The opening 58 is located at one end 64 of the tubular chamber 56 and is sized and shaped so as to allow snug sealing engagement between the insert portion 26 of the monitoring device 10 and inner walls 66 of the tubular chamber 56. The opening 58 has a diameter of 9.5mm.

The sound generator 60 is located at an opposing end 68 of the tubular chamber 56. The sound generator 60 generates a predetermined sound inside the chamber to be sensed by the sound sensor 20 and transmitted to the processor 24 to be stored as a reference sound when the insert portion 26 thereof is received by the opening 58 of the tubular chamber 56. The predetermined sound is in the form of white noise having frequencies in the range of 31 Hz to 16kHz. The sound transmitter 18 of the monitoring device 10 then transmits the reference sound into the chamber 56 to be sensed by the sound sensor 20 as a sensed reference sound. The processor 24 then compares the sensed reference sound to a transmitted reference sound to determine a difference therebetween, which difference represents a deviation in actual sound output of the processor 24. The deviation in sound output of the processor 24 is stored in the processor 24 as a sealed cavity offset in order to account therefore during the monitoring of sound exposure to a user.

It is to be appreciated that the monitoring device 10 is further calibrated according to anatomical characteristics of a particular user's ear canal. The processor 24 of the monitoring device 10 determines a difference between sound transmitted into the ear canal and sensed by the sound sensor 20 when the insert portion 26 is received by the opening 58 of the user's ear canal 16 and incorporating the sealed cavity offset, which difference may represent a deviation caused by the anatomical characteristics of the particular user's ear canal. The deviation is stored in the processor 24 of the monitoring device 10 as a sealed ear canal offset. It is further to be appreciated that the processor 24 is capable of determining the quality of the seal formed between the insert portion 26 of the monitoring device 10 and the walls of the chamber or the ear canal by comparing the sound transmitted into the chamber or ear canal to the sound sensed by the sound sensor incorporating both the sealed cavity and sealed ear canal offsets so as to determine a difference therebetween, wherein a difference exceeding a predetermined level of 3dB indicates that an insufficient seal is formed.

An energising means in the form of a USB power supply arrangement 70, is provided for energising the sound generator 60 in use. The USB power supply arrangement 70 includes a USB port 72 located on the body 54 and is in electrical communication with the sound generator 60 for receiving power via a suitable USB cable 74 which is connected to an external power supply (not shown) in use.

It should be noted that a plurality of computing devices may be configured to receive the information transmitted by the sound sensor transmitter 18. Each of these computing devices may typically have a processor which is configured in a similar manner to the processor 24. The system 100 may therefore include a plurality of computing devices.

The functions of the processor 24 described above could be implemented through appropriate software/firmware which is read/executed by the processor 24. In one example, the processor 24, together with appropriate software, may be configured to provide a mobile app/application which performs the functions of the processor 24 described above.

It is, of course, to be appreciated that the monitoring device in accordance with the invention is not limited to the precise constructional and functional details as hereinbefore described with reference to the accompanying drawings and which may be varied as desired. The inventor believes that the monitoring device in accordance with the present invention is advantageous in that it allows monitoring of listening habits of a user to enable the user to regulate the sound being listened to, to within a safe level thereby preventing damage to sound receptors in the ear and prolonging the ability to hear.