ENVIRONMENT

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention provides for systems and methods relating to processing of a digital signal, including an audio signal, relating to a diver in a deep diving environment.

DESCRIPTION OF THE RELATED ART

Divers who operate in deep diving environments face numerous challenges and hazardous conditions inherent in the environment. Included among them are the risks associated with nitrogen narcosis, decompression sickness, oxygen toxicity, and eguipment failure . Accordingly, many divers venturing into deep diving environments choose to do so eguipped with some form of communication eguipment facilitating communication with other divers and/or the surface to help mitigate the dangers associated with the activity. These divers may come to depend heavily on the reliability of their communications device both for routine diving operations and in the event of an emergency situation. Therefore, the audio guality is a chief concern for a diver, as garbled and distorted audio signals can have grave impact on a diver's ability to communicate in a deep diving environment .

Various aspects of diving in a deep diving environment complicate the use of traditional communication devices . For example, divers in a deep diving environment often use specially adapted gaseous mixtures, which affect transmission of sound waves in ways that ordinary communication devices accustomed for use in typical atmosphere or at sea level are rendered ineffective. Examples of gaseous mixtures a diver may be breathing include heliox, a gaseous mixture of helium and oxygen, trimix, a mixture of oxygen, helium and nitrogen, and various other potential mixtures depending on the conditions of the environment and/or skill of the diver. Furthermore, the gaseous mixture may not be at a standard atmospheric pressure. Because the gaseous mixture is a medium for the propagation of sounds produced by the diver, the composition of the gaseous mixture affects propagation of the sound waves therethrough. These differences in sound propagation accordingly affect the properties of the signal and the communications contained therein. It therefore follows that traditional signal processing methods and devices are unsuitable for operation in the deep diving environment .

Accordingly, what is needed in the art is a system and method for processing of audio signals relating to a diver in a deep diving environment. It would be further beneficial for such processing to take into account various aspects of the diver and/or the environment, including the particular gaseous mixture the diver is breathing. In addition, the benefits of processing the audio signal include yielding a clearer signal that can be more efficiently amplified, processed, and/or transmitted, which enhances the safety of the diver.

SUMMARY OF THE INVENTION

The present invention relates to the processing of a digital signal, such as an audio signal, relating to a diver in deep diving environment. Processing of the digital signal yields a clearer digital signal, which may facilitate operational safety of the diver in the diving environment . For example, a clearer digital signal facilitates communications capabilities of the diver, allowing the diver's voice to be more accurately reproduced and heard by e.g. other divers and/or surface operations. This further enhances the safety of the diver by enabling the diver to notify others of any present conditions or emergency situations. Additionally, processing of a digital signal in accordance with the present invention compensates for any inherent deficiencies in the communications equipment the diver may be using.

However, as previously discussed, processing a digital signal in a deep diving environment requires compensating for various aspects of the deep diving environment that are absent from normal, surface conditions. These aspects may include different gaseous mixtures being breathed by the diver, for example, which distort the sounds the diver produces and therefore the clarity of the digital signal. The gas the diver is breathing may also be administered at a different pressure than standard atmospheric pressure. In particular, divers breathing gaseous mixtures containing helium speak with a drastically higher pitched voice as a result, which negatively impacts communication abilities. Accordingly, the present invention addresses these and other challenges posed by communicating in a deep diving environment .

As explained in further detail herein, a preferred embodiment of the present invention facilitates digital processing of an audio signal to so as to produce higher- quality sound. Further, digital processing of the audio signal may be accomplished in a manner particularly tuned for processing of the vocal range, thereby improving the audio quality of an audio signal that primarily comprises voice communications .

Accordingly, the present invention is directed to a system and method for processing the digital signal produced by a diver in a deep diving environment .

An illustrative embodiment of a system of the present invention comprises an input device structured to receive the signal. Examples of input devices include a microphone. The system comprises a plurality of processing modules collectively configured to process the received signal. Processing of the pitch changed signal may be achieved according to various desired signal processing processes, as discussed further below. The processed signal is output by an output module, which in various embodiments comprises speakers, a transmitter, and/or any other suitable means of outputting .

A pitch changing module changes the pitch of the received signal .

In a preferred embodiment, at least one of the processing modules comprises a first low shelf filter module configured to filter the pitch changed signal. Furthermore, at least one of the plurality of processing modules comprises a first high shelf filter module configured to filter the signal received from the first low shelf filter.

Additionally, at least one of the processing modules may comprise an automatic gain control module configured to adjust a gain of the filtered signal received from said first high shelf filter module. In various embodiments, the automatic gain control module may comprise a compressor and/or a limiter .

Accordingly, at least one of the processing modules comprises a second low shelf filter module configured to filter the gain adjusted signal. Furthermore, at least one of the processing modules comprises a second high shelf filter module configured to filter the signal received from said second low shelf filter module.

The first filters preferably collectively comprise a first center freguency and a first gain value. Similarly, the second filters collectively comprise a second center freguency and a second gain value. Accordingly, the first center freguency and second center freguency are egual in at least one embodiment, and the first gain value and second gain value are the inverse of one another.

In a preferred embodiment, at least one of the processing modules comprises an egualization module configured to egualize the signal received from said second shelf filters. In at least one embodiment, the egualization module comprises a bell filter. The egualization module may be configured to egualize the signal in accordance with at least one predetermined parameter of the signal. In short, predetermined parameters affects the audio properties of the signal, and egualization that accounts for such parameters when egualizing the signal in at least one embodiment produces a better guality signal. Examples of predetermined parameters of the signal include, but are not limited to, the gender of the diver, an age of the diver, a tonality of the diver's voice, a depth at which the diver is diving, and a type of gas the diver is breathing.

In at least one embodiment, the signal is further processed by a static gain control module configured to adjust the gain of the signal. Such processing by the static gain control may facilitate headroom and/or signal-to-noise ratio. Further, the static gain control module in a preferred embodiment is configured to account for further processing, control, transmission, and/or amplification device or devices that may additionally alter the signal.

As is described above, audio communication plays a role in the safety of divers, particularly in a deep diving environment. Accordingly, the present invention relates to a system for processing of an audio signal, such as one comprising voice communications produced by the diver. In various embodiments, these voice communications are relayed and/or transmitted to others, such as other divers, including divers at various depths, or operators at other locations such as the surface .

Other embodiments of the present invention are directed to a method of signal processing, as is further described herein .

These and other objects, features and advantages of the present invention will become clearer when the drawings as well as the detailed description are taken into consideration.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:

Figure 1 is a schematic representation of an illustrative embodiment of the present invention.

Figure 2 is a schematic representation of an illustrative embodiment of the present invention.

Figure 3 is a schematic representation of an illustrative embodiment of the present invention.

Figure 4 is a schematic representation of an illustrative embodiment of the present invention.

Figure 5 is a schematic representation of an illustrative embodiment of a method in accordance with the present invention .

Like reference numerals refer to like parts throughout the several views of the drawings .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As is illustrated by the accompanying drawings, the present invention is directed to systems and methods for processing of a digital signal, including an audio signal, relating to a diver in a deep diving environment.

A preferred embodiment of the present invention comprises a system, generally indicated as 1 in Figure 1. The system comprises an input device 10, a plurality of modules 200, and an output device 100, each of which will be discussed more fully below.

The input device 10 is at least partially structured and/or configured to receive a signal. The signal is a digital signal, and in various embodiments comprises an audio signal, sounds within the audible range (generally defined as approximately 20 Hz to 20 kHz), and/or vocal communications produced by the diver .

The output device 100 is configured to output a signal processed by the plurality of modules 200. Accordingly, the output device 100 is configured to receive and output a signal from the plurality of modules 200. Examples of output devices include transmission devices, such as for wired and/or wireless transmission from a device worn by a diver as well as speakers or other auditory output devices .

With reference to Figure 2, illustrative examples of modules 200 are indicated at 20, 30, 40, 50, 60, 70, 80, and 90. These modules will be discussed in turn. However, though the embodiment of Figure 2 illustrates an order by which a digital signal is processed by the modules 200, it should be noted that the order is not to be interpreted as limiting. Accordingly, various other embodiments may implement alternative orders and/or combinations, including combinations of these and additional or fewer modules 200. As used herein, modules 200 may comprise a device or devices, circuits, circuitry, and/or other components suitable for processing of a digital signal in accordance with the present invention as described and claimed herein.

In the embodiment of Figure 2, the pitch of the received signal 110 is changed, adjusted, etc. by a pitch change module 20. The pitch change module 20 changes the pitch of the received signal 110 by an amount within the range of an increase of one octave to a decrease of two octaves, inclusively. The pitch change module 20 is further configured to transmit a pitch changed signal 120, such as for further processing .

With further reference to Figure 2, the pitch changed signal 120 transmitted by the pitch change module is received by a first low shelf filter module 30. The first low shelf filter module 30 is configured to filter the pitch changed signal 120. The first low shelf filter module 30 is configured to pass all frequencies, but increases or decreases, i.e. boosts or attenuates, the amplitude of frequencies below a predetermined frequency by a specified amount.

A system 1 in accordance with that of Figure 2 further comprises a first high shelf filter module 40. The first high shelf filter module 40 is configured to filter the signal 130 received from the first low shelf filter module 30. Additionally, the first high shelf filter module 40 is configured to increase or decrease the amplitude of frequencies above a predetermined frequency by a specified amount .

In the preferred embodiment, the first low shelf filter module 30 and the first high shelf filter module 40 are correspondingly configured such that the resultant first filtered signal 140 comprises a differential of 24 decibels between its high and low frequencies.

In at least one embodiment, the first low shelf filter module 30 and first high shelf filter module 40 collectively comprise a first center frequency and a first filter gain value .

With reference to Figure 2, the system 1 further comprises an automatic gain control module 50 configured to adjust a gain of the first filtered signal 140 so as to produce and transmit a gain adjusted signal 150. The amount of adjustment of the gain of the first filtered signal 140 differs between embodiments of the system 1. For example, in at least one embodiment, the automatic gain control module 50 is configured to adjust the gain of the filtered signal by an amount within the range of 0 decibels and 20 decibels, inclusively. Additionally, in various embodiments, the automatic gain control module 50 may comprise a compressor and/or a limiter.

In the illustrative embodiment of Figure 2, the gain adjusted signal 150 is then filtered by a second low shelf filter module 60. The second low shelf filter module 60 passes all frequencies, but increases or decreases the amplitude of frequencies below a predetermined frequency by a specified amount .

The system 1 further comprises a second high shelf filter module 70. The second high shelf filter module 70 is configured to filter the signal 160 received from the second low shelf filter module 60. Additionally, the second high shelf filter module 70 is configured to increase or decrease the amplitude of freguencies above a predetermined freguency by a specified amount.

In the preferred embodiment, the second low shelf filter module 60 and second high shelf filter module 70 collectively comprise a second center freguency and a second filter gain value. Additionally, the first shelf filter modules 30, 40 collectively comprise a first center freguency and a first filter gain value. Further still, the first and second center freguencies are egual, and the first and second filter gain values are the inverse of one another.

With further reference to Figure 2, the second filtered signal 170 produced by the second shelf filter modules 60, 70 is transmitted to the output device. However, in various other embodiments, such as those of Figures 3 and 4 discussed below, the second filtered signal 170 is processed further.

With respect to Figure 3, the second filtered signal 170 is transmitted to an egualization module 80 configured to egualize the second filtered signal 170. The egualization module 80 in at least one embodiment is configured to adjust the gain of the signal by an amount within a range of 0 to 25 decibels inclusively. The egualization module 80 may be additionally and/or alternatively configured to egualize freguencies of the signal below 200 Hertz. Furthermore, various embodiments of the egualization module 80 comprise at least one bell filter.

Additionally, in a preferred embodiment, the egualization module 80 is configured to egualize the second filtered signal 170 in accordance with at least one predetermined parameter. Generally speaking, a predetermined parameter should be understood to refer to a property of the digital signal that is to be processed by the system 1, and includes the factors and/or circumstances relating to its creation and/or propagation. Examples include but are not limited to: the diver's gender, the diver's age, the tonality of the diver's voice, a depth at which the diver is diving, and the type of gas the diver is breathing. In various embodiments, the equalization module 80 is configured to equalize the signal in accordance with at least one predetermined parameter. Furthermore, in a preferred embodiment the equalization module 80 is configured to equalize the signal in accordance with a plurality of predetermined parameters, including but not limited to the foregoing.

With further reference to Figure 3, the equalized signal 180 is transmitted to the output device 100. However, in other embodiments, such as that depicted in Figure 4, the equalized signal 180 is further processed.

As shown in the illustrative embodiment of Figure 4, the equalized signal 180 is transmitted to a static gain control module 90. The static gain control module 90 is configured to adjust the gain of the received signal. Such gain adjustment by the static gain control module 90 may comprise adjustment of the signal-to-noise ratio of the signal and/or facilitation of a desired headroom in the resultant static gain adjusted signal 190. In any case, the static gain adjusted signal 190 is then transmitted by the static gain control module 90, such as to the output device 100.

With primary reference to Figure 5, a preferred embodiment of a method 500 in accordance with the present invention is provided. It should further be understood that various embodiments of the method 500 may incorporate the components of the system 1 previously described. In addition, the steps of the method 500, discussed below, need not be completed in the illustrated order.

In the embodiment of Figure 5, the method 500 comprises receiving the digital signal by an input device 510. The pitch of the received signal is then altered by a pitch changing module, as at 520. In at least one embodiment, the degree of the change of the pitch of the received signal is within the range of -2 to +1 octaves. In other words, the pitch of the signal and/or parts thereof may be decreased by as much as two octaves or increased by as much as one octave.

The method 500 of Figure 5 further comprises filtering the pitch altered signal with a first low shelf filter module as at 530, and filtering the resultant signal with a first high shelf filter module, as at 540.

The resultant first filtered signal is then transmitted to an automatic gain control module, which adjusts the gain of the first filtered signal, as at 560.

The gain adjusted signal is transmitted to and filtered by a second low shelf filter, as at 560, and a second high shelf filter, as at 570. The resultant signal may then be output by an output device, as at 600, or further processed.

Additionally, the second filtered signal produced by the second high shelf filter is egualized by an egualization module, as at 580. The resultant egualized signal may then be output by an output device, as at 600', or further processed.

Further, the egualized signal produced by the egualization module is transmitted to a static gain control module, which adjusts the gain of the signal, as at 580. The resultant static gain adjusted signal may then be output by an output device, as at 600", or further processed.

Since many modifications, variations and changes in detail can be made to the described preferred embodiment of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal eguivalents.

Now that the invention has been described,