Communication systems

A communication system providing volume attenuation as a function of distance from the communication source to simulate natural communication.

BACKGROUND

Communication systems (e.g., wireless communication systems) are commonly employed in environments where it is difficult to hear (e.g., noisy environments), such as constructions sites, factories and the like. In a typical noisy work environment, most speech communication is intended for individuals nearby, e.g., between/among workers who may be partnering or collaborating to perform a task. Without the background noise, these individuals would simply speak to each other naturally. However, due to the noise generated in some environments, in addition to the hearing protection devices that are often required in such environments, natural speech patterns are not possible, thereby hindering communication.

SUMMARY

In general terms, this disclosure is directed to a communication system that simulates a natural speech environment.

In one aspect a communication system modulates sound volume based on a distance between the transmitter of the communication and the receiver of the communication.

In another aspect, a communication system modulates sound volume based on transmission impedance occasioned by one or more physical structures.

In a further aspect, a communication system modulates sound volume based on measured radio frequency (RF) signal strength received from the communication transmitter.

DETAILED DESCRIPTION

FIG. 1is a schematic illustration of an example communication system100in accordance with the present disclosure. The communication system100includes a plurality of voice transceiving devices. In the example inFIG. 1, a first voice transceiving device102, a second voice transceiving device104and a third voice transceiving device106are shown. However, it should be appreciated that any suitable number of such voice transceiving devices may be included in the communication system100. Each of the voice transceiving devices (102,104,106) includes a power supply108, a voice transmitting module110having a microphone111, a voice receiving module112having a speaker114, and a regulator module116having a positioning submodule118and optionally a transmission impedance submodule120. Each of the voice transceiving devices (102,104,106) also includes a noise cancellation component122. Each of the voice transceiving devices is associated with one of the users of the communication system100. The communication system100enables its users to orally communicate with one another via the voice transceiving devices.

The power supply108selectively (e.g., via an on/off switch) provides power to the voice transceiving device (102,104,106). Examples of power supplies108include batteries, solar cells, and so forth.

The voice transmitting module110converts a user's voice into an analog audio signal with the microphone111, and transmits the analog audio signal as a digitized waveform or an analog waveform (e.g., a radio frequency (“RF”) signal using digital RF modulation or analog RF modulation) via an antenna to one or more other voice transceiving devices in the communication system100.

The voice receiving module112receives (e.g., via an antenna) digitized wave signals (e.g., RF signals) from one or more other voice transceiving devices in the communication system, converts those signals (e.g., via an antenna) into analog audio signals, and converts the analog audio signals into sound waves that are transmitted to a user's ear with the speaker114.

The regulator module116selectively modulates the audio analog fed to the speaker114according to one or more predetermined algorithms. The form of audio analog fed to the speaker114correlates with characteristics of the sound produced by the speaker114. In some examples, the regulator module116modulates the audio analog fed to the speaker114in order to decrease the volume the speaker114would otherwise produce. According to some example algorithms, the regulator module116attenuates volume as a mathematical function of the distance from the voice transceiver at which the voice communication originates.

In some examples, the regulator module116includes circuitry having one or more electrical components such as electrical comparators, electrical operational amplifiers, digital modulators, digital to analog converters, analog to digital converters, and/or digital filters/decimators. In some examples, the regulator module116is programmable, e.g., via a field programmable gate array, the one or more volume attenuation algorithms being programmed thereby either remotely (e.g., via a Wi-Fi connection), or through a hard connection. In some examples, the regulator module116includes a programmable audio processing engine having one or more analog inputs and one or more analog outputs. By utilizing circuitry having one or more electrical components such as electrical comparators, electrical operational amplifiers, digital modulators, digital to analog converters, analog to digital converters, and/or digital filters/decimators, the audio processing engine modulates one or more audio analog input signals by, e.g., filtering, level control, signal level monitoring, and mixing. Thus in some examples, the regulator module116comprising a programmable audio processing engine receives audio analog inputs from the voice receiving module112, modulates the audio analog input signals, and outputs modulated analog audio signals to the speaker114according to one or more programmed algorithms.

In one example, the regulator module116is an ADAU1772 programmable codec from Analog Devices, Inc. of Norwood. Me. However, other chips and configurations are possible.

The positioning submodule118of each of the receiving voice transceiving devices104,106, for example, measures the distance (d1, d2) between receiving voice transceiving device104,106and the transmitting voice transceiving device102. Such distances can be defined, e.g., as the distance between respective antennas of the relevant transceiving devices. The positioning submodule118measures distance through any suitable means, e.g. via GPS, RF signal strength, Wi-Fi hub triangulation, and so forth.

RF signal strength predictably decreases over distance. Thus, the distance between the receiving voice transceiving device (104,106) and the transmitting voice transceiving device (102) can be determined based on the RF signal strength received from the transmitting transceiving device. This distance is then plugged into an algorithm used by the regulator module to modulate the analog audio signal fed to the speaker114in the voice transceiving device (104,106), resulting in sound waves that have been modulated as a mathematical function of distance from the sound source. Thus, the regulator module116, in conjunction with the positioning submodule118, can simulate natural voice communication by reducing the volume produced at the speaker114of the receiving transceiving device104,106as a mathematical function of the distance from the source of the sound.

In some examples, the positioning submodule118outputs a signal (e.g., an analog signal) corresponding to a distance (a “distance signal”), the distance signal travelling to a programmed audio processing engine in the regulator module116. In these examples, the audio processing engine is programmed to modulate an analog audio signal coming from the voice receiving module112based on the distance signal received, thereafter outputting the modulated analog signal to the speaker114.

It should be noted that factors other than distance can result in RF signal degradation. For example, RF signal strength predictably degrades based on an impeding structure's location relative to the voice transceivers involved, as well as the impeding structure's material, size, and so forth. Some of these factors can also cause varying degrees of attenuation of sound volume in a natural environment. Thus, in some examples of the communication system100, the regulator module116alternatively or further modulates the analog audio signal fed to the speaker114as a mathematical function of transmission impedance created by one or more physical structures S. In some instances, such as when S is a wall that separates a transmitting voice transceiving device102(i.e., the human speaker) from a receiving voice transceiving device104,106(i.e., the human listener), the structure S is capable of causing both an RF signal degradation when the communication system100is in use, as well as a significant volume attenuation in a natural environment (i.e., an environment without the communication system100). In other instances, such as when S is spatially a relatively non-obstructive metallic object (e.g., a metal tool box), the structure S is capable of causing a predictable RF signal degradation when the communication system100is in use, but does not cause significant volume attenuation in a natural environment.

Thus, in some examples, the transmission impedance submodule120can detect a physical structure S (e.g., a wall, an object) between itself and the source of the voice. In some examples, the transmission impedance submodule120also determines one or more parameters of the physical structure S (e.g., height, width, thickness, density, material (e.g. metallic versus non-metallic), etc.). In some examples, the transmission impedance submodule120can also use the positioning submodule118to determine a distance (d3, d4, d5) to the physical structure S.

Based on the relative location and/or characteristics of the structure S as determined by the transmission impedance submodule120, signals (e.g., analog signals) can travel to the regulator module116to modulate (according to a predetermined algorithm) the analog audio signal fed to the speaker114in the receiving voice transceiving device (104,106), resulting in sound waves produced by the speaker114that have been modulated as a result of the presence of the physical structure S. For example, if the structure S is a wall between the transmitting voice transceiving device102and the receiving voice transceiving device (104,106), the algorithm assumes that the structure S would cause a natural volume attenuation in addition to an RF signal degradation, such that the total degradation in RF signal strength received by the receiving voice transceiving device (104,106) is applied to modulate the volume in the speaker114of the receiving voice transceiving device (104,106). Conversely, if the structure S is a relatively small metallic object, the algorithm assumes that the structure S would not cause a natural volume attenuation, and therefore the RF signal strength degradation occasioned by the structure S is subtracted from the total degradation received by the receiving voice transceiving device (104,106) when modulating the volume produced by the speaker114.

In alternative examples, the transmission impedance submodule120includes a predetermined map of the area of use for the communication system100. The map can include spatial and other impedance related information (e.g., size, material) about one or more structures S within the area. In some examples, the communication system100is pre-programmed with such information. The map can take into account locations of one or more structures S within the area, as well as the degree of inherent signal strength degradation occasioned by each such structure (e.g., degradation resulting from the structure's size, material and/or location relative to other structures). The positioning submodule118determines the location of the receiving voice transceiving device (104,106) on the map, i.e., within the area of use for the communication system100and relative to the one or more structures S within the area. The regulator module116then modulates the analog audio signal fed to the speaker114based on the distance between the transmitting voice transceiving device102and the receiving voice transceiving device,104,106(as determined by the positioning submodule118) and the location of the receiving voice transceiving device104,106on the map.

In some examples, the transmission impedance submodule120outputs a signal (e.g., an analog signal) corresponding to a structural impedance (an “impedance signal”), the impedance signal travelling to a programmed audio processing engine in the regulator module116. In these examples, the audio processing engine is programmed to modulate an analog audio signal coming from the voice receiving module112based on the impedance signal received from the transmission impedance submodule120and/or based on the distance signal received from the positioning submodule118, thereafter outputting the modulated analog signal to the speaker114.

The noise cancellation component122reduces the ambient noise present in the environment, such as noise from tools, machinery, construction, demolition, and the like. In some examples, the noise cancellation component neutralizes ambient noise by emitting sound waves that are 180° out of phase with the ambient noise, i.e., active noise attenuation. The noise cancellation component122can also include sound blocking and absorption features in or surrounding the users' ears, such as ear plugs, head phones and so forth (i.e., passive noise attenuation). Active and passive noise attenuation, employed individually or in combination can help protect users of the communication system100from high ambient noise levels and/or improve intelligibility of the received audio by improving the signal to noise ratio.

The noise cancellation component122does not interfere with the transmission of sound to the user's ear via the speaker114. For example, an ear plug can be configured with an unobstructed path (e.g., a bore, tube) leading from the speaker114to the terminal of the ear plug closest to the user's ear drum.

FIG. 2is a perspective view of an example embodiment of the voice transceiving device102ofFIG. 1, which could be equivalently the voice transceiving device104or106. The voice transceiving device102includes a headset140having a band142connecting the ear pieces144and146, a mouthpiece148, and an electronics compartment150. The ear pieces144and146and the mouthpiece148are electronically connected to one another. The headset140is placed about a user's head, neck, helmet or hard hat such that the ear pieces144and146can be placed in the user's ears and the mouthpiece148is adjacent the user's mouth. The ear pieces144and146include passive noise attenuation elements152. The passive noise attenuation elements152can be configured to block, absorb, and/or cancel ambient noise, i.e., to provide passive noise attenuation. The passive noise attenuation elements152can serve to attenuate ambient noise by absorbing or deflecting the noise before it reaches the user's ear. In some examples, the passive noise attenuation elements152include a compressible material (e.g., a foam) that hugs the interior of the user's ears. A variety of configurations and materials can be used for the passive noise attenuation elements152.

The mouthpiece148includes the voice transmitting module110and the microphone111described above. One or both of the ear pieces144,146includes the speaker114of the voice receiving module112as described above. In some examples, one or both of the ear pieces144,146include an unobstructed path from the speaker114to the user's ear. The remaining components of the voice receiving module112are disposed in one or both of the ear pieces144,146and/or in the electronics compartment150. The electronics compartment150includes circuitry required for performing active noise attenuation, housing the power supply108and the regulator module116having the positioning submodule118and the transmission impedance submodule120, as described above. In some examples, the electronics compartment150also includes one or more antennas for transmitting and receiving RF signals, and for providing a location reference for the voice transceiving device used by the positioning submodule118to determine distance from another transceiving device.

In some examples, each user of the communication system100ofFIG. 1has access to or wears a headset140. For a listening user wearing a headset140, an RF signal from a transmitting transceiving device is received by an antenna in the electronics compartment150. Based on the RF signal strength received by the antenna and the causes for any signal strength degradation (as discussed above), the regulator module116determines to what degree an analog audio signal corresponding to the RF signal is modulated. The voice receiving module112then feeds the speaker114with the modulated analog audio signal which is then transmitted to the listening user's ear or ears via the speaker114, the speaker114operating to convert the analog audio signal into sound pressure.

The degree of modulation could be zero, insignificant, substantial or total, the latter being in which zero analog audio signal is generated and no sound produced by the speaker114. It should be also appreciated that components of the headset140can process RF signals coming from multiple sources (i.e., multiple transceiving devices) simultaneously or substantially simultaneously, and evaluate the proper amount of volume modulation for each source before transmitting the analog audio signals to the speaker114. Thus, for example, the communication system100may allow for a single user to hear one or more user's voices while at the same time actively minimizing or eliminating one or more voices from other users of the communication system100. In this manner, specific communicating groups can be established, in which certain users of the communication system100are included in a group that can hear or be heard by other members of the group, while other users are excluded from a group, and thus cannot hear or be heard by members of the group.

Additionally, in some examples a unique digital address associated with each headset140can be used to determine which headsets140can communicate (i.e., within a communicating group). Each user can select headsets140with which to communicate by selecting their corresponding addresses. In addition or alternatively, a centralized operator of the communication system100can be used to selectively route audio to specific headsets140, e.g., by selecting specific headset addresses.

Likewise, the communication system100can be configured to allow communication between the headsets140and a centralized operator of the communication system100, e.g., to facilitate the formation of communicating groups, for public announcements made by the operator to all users of the communication system, or so forth. In addition to routing communications to users of the system100within the same local area or vicinity, in some examples the centralized operator can also be used to route audio signals to remote communication devices, e.g., via one or more RF hubs that extend communication coverage to locations remote from the communication system100. The operator may be connected to the one or more RF hubs through any suitable means, e.g., wirelessly or through an Ethernet connection.

For a speaking user wearing a headset140, the speaker's voice is picked up by the microphone111disposed in the mouthpiece148. The microphone111converts the sound pressure of the user's voice into an analog audio signal that travels to the electronics compartment150, where it is transmitted via the antenna as an RF signal to other headsets140in the communication system100.

As discussed above, the regulator module116selectively modulates the analog audio signal fed to the speaker114according to one or more predetermined algorithms. For example, the predetermined algorithm(s) can apply one of a variety of models to govern the decay of the sound volume as a mathematical function of the distance from the transmitting transceiving device. In one example, the algorithm causes a modulation in the analog audio signal that results in a sound volume decay as a linear mathematical function of distance, the volume decreasing at a consistent rate over distance. See the example “Linear Decay” plot inFIG. 3. In another example, the algorithm causes a modulation in the audio analog that results in little or no volume decay up to a threshold distance followed by rapid, exponential decay thereafter. That is, the volume level remains fairly constant within a certain proximity of the receiving transceiver, and then decreases rapidly. See the example “S-Curve Decay” plot inFIG. 4. In a further example, the algorithm causes a modulation in the analog audio signal that results in steady (e.g., linear) sound volume decay up to a threshold distance, followed by an abrupt total reduction to zero volume thereafter, rendering essentially inaudible voice transmissions originating beyond the threshold distance. See the example “Decay Cut-Off” plot inFIG. 5. In still further examples, the algorithm causes a modulation in the analog audio signal that results in logarithmic sound volume decay over distance. In a particular example, the sound volume decays according to an equation that approximates sound attenuation in a natural environment:
P2=P1+20 log10(d1/d2),
where d1is the location of the sound source, d2is the reference location, P1is the sound pressure at d1and P2is the sound pressure at dz.

It should be appreciated that the headset140can be modified in various ways. For example, the headset can include a single earpiece instead of two ear pieces. An ear loop can be used about the user's ear to keep the headset in place. One or more components of the headset (e.g., the electronics compartment) may be separate from the headset and connected thereto either with one or more wires or wirelessly. For example, the electronics compartment may be housed in a housing separate from the headset that can be mounted to another portion of the user's body, e.g., a belt, pants or a shirt. In some examples, the headset can use a BLUETOOTH® device. In some examples, one or more components of the headset (e.g., the ear pieces, the mouth piece, the electronics compartment, and/or the noise cancellation element) can be mounted directly to an article of clothing or gear worn by the user on or about the user's head, e.g., a helmet, a hard hat, or a pair of goggles or other protective gear.

In some embodiments, one or more of the voice transceiving devices (e.g., the voice transceiving devices102,104,106) includes a regulator module override to selectively override the regulator module116, thereby preventing modulation by the regulator module of the analog audio signals sent to the speaker114. The regulator module override may be activated remotely (e.g., system wide for the entire communication system100), or individually at the transceiving device. For example, if a user of the communication system100wishes to communicate a message to everyone in the communication system (e.g., a public address), in some examples that user may remotely disable each user's regulator module116. In some examples, each regulator module116in the communication system100is automatically overridden for public address announcements made over the communication system100. In some examples, a voice transmitting user can select specific voice transceiving devices on which to override the regulator module116(e.g., by selecting one or more digital addresses of other headsets140, as described above). In some examples, a voice receiving user can override the regulator module116in his/her transceiving device with respect to all other transceiving devices in the communication system100. Alternatively, the voice receiving user can override the regulator module116in his/her transceiving device with respect to one or more selected other transceiving devices in the communication system100(e.g., by selecting one or more digital addresses of other headsets140, as described above). In alternative examples, a centralized operator of the communication system can make announcements (e.g., page one or more individuals) via an intercom and speakers disposed throughout the area of the communication system100for message repetition that can be heard by users of the system100without wearing their headsets140.