Field of Technology

The present invention relates to a visual aid system for assisting hearing-impaired individuals.

Background

Systems and methods for conveying information visually to hearing-impaired individuals are known, for example, sign language and closed captioning. However, these systems and methods would only assist a hearing-impaired individual in certain circumstances, such as when the individual is within sight of another person communicating through sign language, or when the individual is viewing closed caption television. These systems and methods therefore would not assist a hearing- impaired individual when a particular sound exists that is an impromptu signal of certain circumstances arising, such as a doorbell ringing, a smoke alarm, an approaching vehicle or a crying baby.

Hearing aids are also known to assist hearing-impaired

individuals who still have some ability to hear. However, hearing aids would not assist an individual who is severely hearing-impaired or totally deaf in the circumstances described above .

Summary of the Invention

According to a first aspect, the present invention provides a visual aid system for assisting hearing-impaired individuals, the system comprising:

a light emitter capable of emitting different colours of light;

a sound detector arranged to detect sound and produce a signal representative of the detected sound; and a signal processor in communication with the sound detector and the light emitter, the signal processor arranged to detect a plurality of different frequencies in the signal, at least some of the different frequencies falling within different predetermined frequency ranges;

wherein each frequency range is associated with a different frequency range colour and the system is arranged to cause the light emitter to emit an output colour that is a combination of the frequency range colours associated with respective frequency ranges in which a frequency of the signal falls .

The sound detector may be a microphone arranged to detect audible sound and output an audio signal representative of the detected sound. The audio signal may be an electrical signal, such as a voltage signal.

The signal processor may comprise a plurality of frequency filters, each frequency filter associated with one of the frequency ranges and arranged to pass a portion of the signal falling within an associated frequency range. The frequency filter may be in communication with user controls to allow a user to select options relating to filter settings, such as threshold levels.

Each frequency range colour may be composed of two or more base colours. The base colours may consist of red, green and blue. The signal processor may be configured to apply a predetermined weighting to each base colour, and the output colour may be a combination of all the weighted base colours associated with each frequency range in which a frequency of the signal falls .

A proportion of a particular frequency range colour in the output colour may be dependent on an intensity of the portion of the signal falling within each frequency range associated with the particular frequency range colour. The light emitter may be an RGB light emitting diode (LED) .

The system may further comprise an amplitude filter that filters the signal such that a portion of the signal below and/or above an amplitude threshold does not affect the output colour emitted by the light. Each amplitude threshold may be adjustable. The amplitude filter may be in communication with user controls to allow a user to adjust each threshold.

The system may comprise a plurality of amplitude filters, amplitude filter associated with a respective one of the plurality of frequency filters.

The system may comprise a light sensor in communication with the light emitter, the light sensor causing an intensity of light emitted by the light emitter to vary depending on external lighting conditions .

According to a second aspect, the present invention provides portable device comprising the system according to the first aspect .

The portable device may comprlse a fastener for fastening the device to an object. The fastener may for example be an adhesive or a mechanical fastener such as a clip. The fastener may removably attach the portable device to an object, such as hook and loop fasteners. The object may be a pair of spectacles, for example, the fastener may attach the device to an arm of the pair of spectacles.

According to a third aspect, there is provided an electronic device incorporating the system according to the first aspect. The electronic device may be a computing device or smart device, such as a laptop, a mobile phone, an electronic notebook or a TV. The electronic device may comprise a visual user interface, which may comprise the light emitter. Brief Description of the Drawings

Figure 1 is a schematic block diagram of a visual aid system according to an embodiment of the present invention.

Figure 2 is a side view of the system embodied as a portable device mounted onto spectacles.

Figure 3 is a schematic block diagram of the visual aid system according to a further embodiment of the invention.

Figure 4 is a representation of signals that have been processed according to an embodiment of the invention.

Figure 5 shows weighting functions mapped onto a logarithmic scale that may be used in a visual aid system according to an embodiment of the invention.

Figure 6 is a schematic block diagram of a visual aid system according to another embodiment of the present invention.

Figure 7 is a schematic block diagram of a visual aid system according to yet another embodiment of the present invention. Figure 8 is a circuit diagram of a component of the visual aid system shown in Figure 7.

Figure 9 is a circuit diagram of another component of the visual aid system shown in Figure 7.

Figure 10 shows weighting functions mapped onto a logarithmic scale that may be used in a visual aid system according to another embodiment of the invention . Figure 11 shows weighting functions mapped onto a logarithmic scale that may be used in a visual aid system according to yet another embodiment of the invention. Detailed Description

Figure 1 illustrates a visual aid system 10 for assisting hearing-impaired individuals according to an embodiment of the invention. The system 10 comprises a sound detector 12, a light emitter 14 capable of emitting different colours of light, and a signal processor 16. The sound detector 12 is arranged to detect sound and produce a signal in response to detected sound. The signal processor 16, which is in communication with the sound detector 12 and the light emitter 14, is arranged to detect and distinguish between a plurality of different frequencies in the signal produced by the sound detector 12 in response to detected sound. Preferably, the sound detector is a microphone 12 arranged to detect audible sound, and output an audio signal representative of the detected sound.

In the system 10 in Figure 1, at least some of the different frequencies detected fall within different predetermined frequency ranges. Further, each frequency range is associated with a different frequency range colour. For example, a first frequency range may be 20-500 Hz and may be associated with the colour red, while a second frequency range may be 500-10,000 Hz and may be associated with the colour blue. The system 10 is arranged to cause the light emitter 14 to emit an output colour that is a combination of the frequency range colours associated with respective frequency ranges in which a frequency of the audio signal falls. Thus, continuing with the example above, if an audio signal includes frequencies in the first and second frequency ranges, the output colour emitted by the light emitter 14 will include a combination of some red and some blue.

An advantage of the system 10 is that by emitting an output colour that is a combination of frequency range colours, the system 10 may provide an indication of the full sound

environment to a user. If for example there are multiple different sounds in an environment, but a greater proportion of sound in lower frequencies, the light emitter 14 may emit a mixture of warm colours tending towards red rather than blue. It is envisioned that over time a user might learn that particular colours are representative of particular sounds . According to a preferred embodiment, the sound detector is a microphone 12 arranged to detect audible sound, and output an electrical audio signal representative of the detected sound. Also preferably, the system 10 is arranged in a portable device that is permanently attachable to an object, such as via adhesive, or demountably attachable to an object, such as via a clip. Accordingly a user can place a device comprising the system 10 at a location frequently within the user' s field of vision, such as spectacles, headwear or an item of clothing, so that the system 10 can provide assistance to the user wherever he or she may be. For example, with reference to Figure 2, a device 11 including the system 10 is shown attached to an arm 19 of a pair of spectacles 18 such that light emitted by the light emitter 14 is in a user' s field of vision when the spectacles 18 are worn.

Figure 3 shows various components of the system 10 in more detail. In operation, the system 10 processes the audio signal in blocks, for instance 200mS in duration, corresponding to a sample of sound detected by the microphone 12. The system 10 comprises an analogue-to-digital converter (ADC) 20 connected to the microphone 12. The ADC 20 converts sound waves detected by the microphone 12 into a digital signal and sends the signal to the signal processor 16. In this embodiment, the signal processor 16 is a digital signal processor such as a

microprocessor or microcontroller. Thus, it will be appreciated by those skilled in the art that the processor 16 may be configured to execute program instructions stored in a memory of the processor 16 or external to the processor 16. Once

processed, the signal is sent to digital-to-analogue converter (DAC) 22, which converts the digital signal into an analogue signal such as voltages to be input into the light emitter 14. The light emitter in this example is in the form of a red-green- blue (RGB) light emitting diode (LED) 14.

Those skilled in the art will also appreciate that according to alternative embodiments the ADC 20 and/or DAC 22 may be incorporated into the signal processor 16. Furthermore, the

ADC/DAC may be configured to perform any suitable technique for signal conversion. For example, the DAC 22 may be comprise a module in the signal processor 16 arranged to perform digital modulation methods such as pulse width modulation and/or pulse position modulation.

More specifically, the signal processor 16 comprises a plurality of frequency filters and at least one amplitude filter in the form of digital frequency and amplitude filters . Each frequency filter F1-F8 is associated with a respective amplitude filter P1-P8, such that once processed by a frequency filter, the signal or portion thereof is sent to the respective amplitude filter for further processing. In this particular embodiment, there are 8 frequency filters represented as F1-F8 in Figure 3. Each filter F1-F8 is

associated with one of 8 predetermined frequency ranges denoted as R1-R8, and is arranged to pass a portion of the audible sound as a transduced audio signal outputted by the microphone 12 falling within an associated frequency range. Further, the amplitude filters P1-P8 are associated with a threshold level such that any portion of a signal falling below a threshold level is disregarded. The threshold levels may be adjusted by user controls (described in more detail below) .

According to a specific example, the predetermined frequency ranges R1-R8 corresponding to frequency filters F1-F8, and corresponding frequency range colours, are shown in Table 1 below. Therefore, if the microphone 12 outputs an audio signal having frequencies of about 80 Hz and about 250 Hz, frequency filter F2 will pass the 80 Hz portion of the signal and filter F4 will pass the 250 Hz portion of the signal. Ultimately, the output colour emitted by LED 14 will then be a mixture of yellow and red.

Table 1

Having received various signal portions from the frequency filters F1-F8, the amplitude filters P1-P8 are configured to first convert the filtered signals from F1-F8 into a (digital) full wave rectified signal, and then pass only the portion of the signal above the amplitude threshold level. For example, Figure 4 shows a full wave rectified signal 24a processed by an amplitude filter P1-P8, which is then further processed to form signal 24b to set the portions of signal 24a below threshold level 26 to the threshold level 26. Accordingly, the lowest signal level of signal 24b becomes the new zero amplitude reference for signal 24b. This provides the advantage that background noise that may not be of any relevance can be disregarded. The amplitude filters P1-P8 then pass respective filtered portions of the signal to a control module 23.

The control module 23 processes the received signals according to program instructions and sends an output into the DAC 22. In this example, the control module 23 executes instructions regarding how the frequency range colours are weighted to produce the output colour, as described below, and hereafter will be called a weighting module 23. Continuing with the specific example above, each frequency range colour is composed of a combination of base colours . Preferably, the base colours are red, green and blue, i.e. primary colours. The base colours can be any colour, however using the primary colours provides the advantage that any other colour can be obtained by mixing the primary colours in different proportions. In this regard, for each frequency filter F1-F8, the weighting module 23 is configured to apply a predetermined weighting to each base colour.

According to this embodiment, the predetermined weightings are obtained by using the information provided in Figure 5, which maps each frequency filter F1-F8 (with ranges according to Table 1) against a logarithmic frequency scale 28. In the frequency scale 28, the horizontal axis 30 represents frequency in Hz and the vertical axis 32 represents a weighting amount (0.0 to 1.0) . Weighting functions or curves representing base colour

weightings can be plotted onto the scale as desired. According to a particular embodiment: the solid curve 34 corresponds to a weighting for the base colour red; the dotted curve 36

corresponds to a weighting for the base colour green; and the grey curve 38 corresponds to a weighting for the base colour blue .

Further, a midpoint M of each frequency range F1-F8 is used to determine the specific weightings for the base colours allocated to each filter F1-F8. The midpoint M of each filter F1-F8 can be obtained by the formula:

(Zn-1)¾(1og —IogL)

log L+

M (FTI) ^~* 2E

(Equation 1)

In Equation 1:

• ^Λ η' is the filter number;

• ^(Fn)' is the midpoint of any filter Fn; • ^Λ Ε' is the total number of filters;

• ^Λ Ι is the lowest frequency in the logarithmic scale; and

• ^Λ Η' is the highest frequency in the logarithmic scale.

Thus, according to Equation 1 the midpoints M for each filter F1-F8 are shown in the second column of Table 2 below. Also, the intersection between each plot 34, 36 and 38, and vertical lines 40a-40h extending from each midpoint M are shown in the third column of Table 2. Finally, the last column of Table 2 shows the actual base colour proportions or weightings derived from the third column, which are to be applied to a signal falling within the respective filter range. Notably, the base colour weightings for each filter produce the respective frequency range colours shown in Table 1 above. Table 2

Note that in the third column of Table 2 above, the fractions 1/3, 2/3, 1/6 etc. correspond to fractions of the full weighting amount (1.0) of the vertical axis 32.

The weighting module 23 uses the weightings in the last column of Table 2 to determine an aggregate value for the base colours across all filters F1-F8 that register a signal. In particular, the weighting module 23 applies the weightings to an amplitude or intensity of a portion of the audio signal falling within a respective frequency range. For example, if an 80 Hz signal portion passed by filter F2 has an intensity of 60dB, and a 250 Hz signal portion passed by filter F4 has an intensity of lOOdB, then the aggregate value for each of the base colours will be:

Red = (100%)*60 + (50%)*100 = 110 units Green = (0%)*60 + (50%)*100 = 50 units

Blue = (0%)*60 + (0%)*100 = 0 units The output colour emitted by RGB LED 14 will therefore be about 69% red, 31% green and 0% blue, which will be approximately an orange colour. The output colour is therefore a combination of all the weighted base colours associated with each frequency range R1-R8 in which a frequency of the audio signal falls. It will be appreciated that units other than decibels can be used to represent signal intensity. It will also be appreciated that an increasing audio frequency from for example 50Hz to 10kHz will cause the LED 14 to emit light changing from red to yellow to green to cyan to blue, whilst the intensity of the light will be approximately proportional to the intensity of the sound being received by the microphone 12.

To emit the output colour, in this example, the RGB LED 14 comprises three distinct LEDs - a red LED, a green LED and a blue LED - which are placed in close proximity to each other so that their colours mix and the RGB LED 14 emits another colour. Emitting the individual red, green and blue LEDs 14a, 14b and 14c respectively at different proportions allows the RGB LED to emit different colours. The signal processor 16 outputs the aggregate values for red, green and blue calculated by the weighting module 23 to the DAC 22. The DAC 22 then converts the red, green and blue aggregate values to respective signals to power the red, green and blue LEDs 14a, 14b and 14c respectively of the RGB LED, for example through digital modulation

techniques.

It will be appreciated that any suitable frequency ranges, amplitude ranges, amount of frequency filters or amplitude filters, frequency range colours, base colours and base colour weightings may be used. Also, different methods for determining or visualising base colour weightings can be used. For example, instead of using the intersections between curves 34, 36 and 38 and the midpoints M(Fn) in Figure 5, Figure 10 shows another method of indicating base colour weightings.

Like Figure 5, Figure 10 shows a logarithmic frequency scale 28 with horizontal axis 30 representing frequency in Hz and vertical axis 32 representing a weighting amount (0.0 to 1.0) . However, in Figure 10 the base colour weightings associated with each frequency filter F1-F8 are represented by horizontal portions 41a-h of stepped curve 43. Each portion 41a-h aligns with and spans a bandwidth of a respective frequency filter Fl- F8, such that portion 41a corresponds to Fl, portion 41b corresponds to F2 , portion 41c corresponds to F3 etc. In particular, the shaded area 45a is associated with the base colour red; the shaded area 45b is associated with the base colour green; and the shaded area 45c is associated with the base colour blue. The base colour weightings are indicated by the proportion of the red, green or blue shaded area within a bandwidth for each frequency range F1-F8 up to a horizontal portion 41a-h. For example, for filter F2 the proportion of green shading 45b up to horizontal portion 41b is about 1/3, and the proportion of red shading 45a up to horizontal portion 41b is about 2/3.

As another example, the system 10 may be arranged to be particularly suited to detect the human voice by selecting frequency ranges and base colour weightings as described below.

Table 3 below shows approximate average frequency ranges for a typical male, female and child's voice (second column) . The upper frequencies may be reached for example when the individual is singing. Table 3 below also shows approximate average frequency ranges for a typical male, female and child's voice when speaking (third column) .

Table 3

For the system 10 to be more sensitive to the ranges in Table 3, the frequency ranges, frequency range colours and base colour weightings shown in Table 4 below may be used for the frequency filters F1-F8 instead of the frequency ranges in Table 1. This is illustrated in Figure 11, which is in the same style as Figure 10 and shows a logarithmic frequency scale 28 with horizontal axis 30 representing frequency in Hz and vertical axis 32 representing a weighting amount (0.0 to 1.0) . The shaded area 47a is associated with the base colour red; the shaded area 47b is associated with the base colour green; and the shaded area 47c is associated with the base colour blue. The base colour weightings are indicated by the proportion of the red, green or blue shaded area within a bandwidth for each frequency range F1-F8 up to an associated horizontal portion 49a-h of the stepped curve 43s. These base colour weightings are also shown in the third column of Table 4 below.

Table 4

Freq. Frequency range Base colour Frequency range filter (Hz) weightings colour (approx.)

Fl Rl - 20 to 93 100% red Red

F2 R2 - 93 to 144 67% red, 33% green Deep orange

F3 R3 -> 144 to 224 33% red, 67% green Yellow orange

F4 R4 - 224 to 346 100% green Green

F5 R5 - 346 to 537 75% green, 25% blue Green cyan

F6 R6 - 537 to 832 50% green, 50% blue Cyan F7 R7 - 832 to 1290 25% green, 75% blue Light blue

F8 R8 - 1290 to 20k 100% blue Blue

Table 5 below shows the frequency filters (second column) th may register a signal comprising frequencies that may be included in a typical male, female and child' s voice when speaking, and a possible colour or colour variation emitted the RGB LED 14.

Table 5

Thus, according to an example, if an 80 Hz signal portion passed by filter Fl has an intensity of 60dB, and a 250 Hz signal portion passed by filter F4 has an intensity of lOOdB, then the aggregate value for each of the base colours will be: Red = (100%)*60 + (0%)*100 = 60 units

Green = (0%)*60 + (100%)*100 = 100 units

Blue = (0%)*60 + (0%)*100 = 0 units

The output colour emitted by RGB LED 14 will therefore be about 37.5% red, 62.5% green and 0% blue, which will be approximately a yellow green colour. Thus, a system 10 according to this embodiment provides a distinct difference between typical male, female and children's voices. Therefore, when a hearing-impaired individual is among a group of people, this distinction may assist the individual in recognising who is speaking, even if the person speaking is not within the individual's direct view.

Turning now to Figure 6, further components of the system 10s according to other embodiments will now be described. The same or similar reference numerals will be used for components that have been previously described. The system 10s may be configured such that the intensity of light emitted by LED 14 is dependent on external lighting conditions. This can be done for example via a light sensor, such as a light dependent resistor (LDR) 42 in communication with the signal processor 16 via a further ADC 44. In

particular, the LDR 42 may output a voltage signal

representative of ambient light conditions. The ADC 44 then converts this voltage signal to a respective digital signal sent to the signal processor 16, which may then automatically set the intensities of the red, green and blue outputs from the processor 16 according to the ambient light digital signal. For example, the signal processor 16 may compare the ambient light signal to a scale, and prior to being sent to the LED 14, adjust the signal outputs for red, green and blue proportionately according to the position of the ambient light signal with respect to the scale. As another example, the signal processor 16 may set a peak brightness for the LED 14 corresponding to the ambient light signal, for instance by using a further adjustable threshold filter. Accordingly, the LED 14 may emit dimmer light in low light conditions and brighter light in good lighting conditions .

The system 10s may further comprise a power supply 46 preferably in the form of a rechargeable battery. This provides the advantage of allowing the system to be integrated into a portable device.

Further, the system 10s may comprise a connection port 48 such as a USB port allowing for various functions such as: external data transfer with the signal processor 16; providing external power to the system 10s; recharging of a rechargeable battery 46; connecting an external RGB LED via a cable; connecting a radio frequency link for data transfer for functions such as interfacing with software applications in other devices. For example, remote cabled RGB LED assembly 50 comprising RGB LED 52 connected to a USB connector 54 can be plugged into the USB connector 48 so that LED 52 functions in a similar manner to LED 14 in the system 10s, and optionally causes LED 14 to be deactivated .

The system 10s may also comprise user controls to allow a user to turn the system on and off and/or select various settings, such as amplitude threshold settings of the amplitude filters P1-P8 and/or brightness settings for the LED 14. For example, the system 10s may be configured such that a momentary press button 56 operatively connected to the signal processor 16 allows the user to select different options or settings depending on when the button 56 is pressed and/or the duration of the press. According to a specific example, the processor 16 and button 56 may be configured to cycle through a sequence of options each time the button 56 is pressed. For example, in the sequence of options l)-5) below:

1) a first press of the button 56 may turn the system 10s on with a first amplitude threshold setting such that signals with intensities above the first (relatively low) threshold are passed, and cause the system 10s to indicate the new setting by the LED 14 flashing red once;

2) a second press may set the amplitude threshold for

amplitude filters P1-P8 to a second amplitude threshold higher than the first threshold such that only signals with an intensity higher than the second threshold are passed, and cause the system 10s to indicate the new setting by the LED 14 flashing red twice; 3) a third press may set the amplitude threshold for

amplitude filters P1-P8 to a third amplitude threshold higher than the second threshold such that only signals with an intensity higher than the third threshold are passed, and cause the system 10s to indicate the new setting by the LED 14 flashing yellow once; 4) a fourth press may set the amplitude threshold for amplitude filters P1-P8 to a fourth amplitude threshold higher than the third threshold such that only signals with an intensity higher than the fourth threshold are passed, and cause the system 10s to indicate the new setting by the LED 14 flashing yellow twice;

5) a fifth press may set the amplitude threshold for

amplitude filters P1-P8 to a fifth amplitude threshold higher than the fourth threshold such that only signals with an intensity higher than the fifth threshold are passed, and cause the system 10s to indicate the new setting by the LED 14 flashing blue once;

6) a sixth press may set the amplitude threshold for

amplitude filters P1-P8 to a sixth threshold higher than the fifth threshold such that only signals with an intensity higher than the sixth threshold are passed, and causing the system 10s to indicate the new setting by the LED 14 flashing blue twice;

7) a seventh press may revert the setting back to setting 1) ; and

8) a prolonged press may turn the system 10a off.

It will be appreciated that the system 10s may be configured to alert the user that particular options have been selected, or of particular circumstances, through various visual indicators such as the LED 14 emitting a distinct pattern of light pulses. For example, the RGB LED may output a different pattern of white light pulses to alert the user of low battery power conditions.

Figures 7 to 9 show a system 60 according to another embodiment of the invention. The system 60 differs from the systems 10 and 10s in that analogue signal processing techniques are utilised instead of digital signal processing. Again, the same or similar components will be denoted with the same reference numeral. The system 60 comprises a microphone 12, an analogue signal processor 62, a light sensor 42 and a light emitter 14 in the form of an RGB LED. The signal processor 62 includes a signal amplifier 64 to amplify the audio signal outputted by the microphone 12. The processor 62 further comprises frequency filters such as a low-pass filter (LPF) 66, band-pass filter (BPF) 68 and high-pass filter (HPF) 70, which receive the signal from the amplifier 64. For example: the LPF 66 passes portions of the audio signal lower than a particular LPF threshold; the BPF 68 passes portions of the audio signal between a particular BPF frequency range; and the HPF 70 passes portions of the audio signal above a particular HPF threshold.

The signal processor 62 further provides amplitude filters 72, 74 and 76, to limit the amount of signal from the frequency filters passed onto the RGB LED 14. The amplitude filter 72 receives signals from LPF 66, the amplitude filter 74 receives signals from BPF 68, and amplitude the filter 76 receives signals from the HPF 70. In particular, each amplitude filter 72, 74 and 76 is provided with a voltage threshold level such that the filters 72, 74 and 76 only pass signals above the voltage threshold level to the LED 14.

The voltage threshold level of the amplitude filters 72, 74 and 76 may be set by virtue of a settings module 78, which is shown in more detail in Figure 8. In this particular embodiment, the settings module 78 comprises a switch 82 that has four

positions: 82a, 82b, 82c and 82d. In Figure 8, the switch is shown in position 82a, wherein the settings module 78

disconnects a power supply 92 (see Figure 7) between connector 80 and the remainder of the system 60. On the other hand, if the switch 82 moves to positions 82b, 82c or 82d, different voltage thresholds are set for amplitude filters 72, 74 and 76.

In particular, if the switch 82 moves to the right to position 82b, the power supply 92 is connected in circuit with a common resistor 84 and a first threshold resistor 86, such that a first voltage threshold is applied to the amplitude filters 72, 74 and 76. Likewise, if the switch 82 moves to position 82c, the resistor 84 and a second threshold resistor 88 are in circuit, and if the switch 82 moves to position 82d, the resistor 84 and a third threshold resistor 90 are in circuit. It will be appreciated that the first, second and third threshold resistors 86, 88 and 90 have different resistor values so as to produce different voltage threshold values.

Figure 9 shows a further circuit representative of any of the amplitude filters 72, 74 and 76. In particular, the output from a respective frequency filter 66, 68 and 70 is fed into an input 94 of a voltage comparator 98. Furthermore, the settings module 78 provides the first, second or third voltage threshold respectively to the filter 72, 74 or 76 via an input 96 of the voltage comparator 98. If a voltage signal from a frequency filter 66, 68 and 70 exceeds that of a corresponding voltage threshold, the voltage comparator 98 switches on a field effect transistor ( FET ) switch 100 so that the voltage signal is passed to a respective red, green or blue 14a, 14b, 14c LED of the RGB LED, preferably via a buffer 102. It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention. For example, data may be transferred from a remote device to a simple receiver and a RGB LED via wired or wireless connection. Furthermore, the system 10, 10s or 60 may be embodied in a portable device comprising a protective coating enclosed within a sufficiently thin plastic moulding so as to allow the microphone 12 to receive sound through the protective coating. As another example, a portable device comprising the system 10, 10s or 60 can be attached to eyewear, hats, bracelets, pendants,

ornaments, car windscreens, car dashboards, a TV or any other suitable object via any suitable adhesive or fastener, such as a clip, Velcro fastener, fastener, magnet, socket, receptacle, or tape .

As another example, the present invention may be incorporated in any suitable form of hardware or software emulation. For example, the invention may be incorporated into any suitable electronic device such as whitegoods, household appliances, clocks, watches and radios with electronic display media, as well as mobile phones, tablets, computers, and TVs.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word

"comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.