System, method, and apparatus for generating and digitally processing a head related audio transfer function
11202161 · 2021-12-14
Assignee
Inventors
- Ryan J. Copt. (Port St. Lucie, FL, US)
- Joseph G. Butera, III (Stuart, FL)
- Robert J. Summers, III (Port St. Lucie, FL)
- Mark Harpster (Port St. Lucie, FL, US)
- David Lopez, JR. (Port St. Lucie, FL, US)
Cpc classification
H04S2420/01
ELECTRICITY
H04S7/302
ELECTRICITY
H04R2201/107
ELECTRICITY
H04R5/027
ELECTRICITY
H04R2205/022
ELECTRICITY
International classification
Abstract
The present invention provides for an apparatus, system, and method for generating a head related audio transfer function in real time. Specifically, the present invention utilizes unique structural components including a tragus structure and an antihelix structure in connection with a microphone in order to communicate the location of a sound in three-dimensional space to a user. The invention also utilizes an audio processor to digitally process the head related audio transfer function.
Claims
1. A wearable apparatus for hearing enhancement and protection capable of generating a head related audio transfer function for a user, said wearable apparatus comprising: at least one in-ear assembly disposed in an operative position comprising: a tragus structure on an exterior surface of said at least one in-ear assembly, an antihelix structure on said exterior surface of said at least one in-ear assembly, a microphone aperture on said exterior surface of said at least one in-ear assembly, said microphone aperture in air flow communication with an external environment, a microphone channel on an interior of said at least one in-ear assembly, said microphone channel in air flow communication with said microphone aperture, a microphone attached to an end of said microphone channel, a playback module connected to said microphone, an isolation baffle disposed to isolate said microphone from said playback module, an auditory channel connected to said playback module, said auditory channel disposed in communication with a user's ear to convey the head related audio transfer function, when in said operative position, and a preamplifier configured to receive an audio signal, an audio processor configured to receive an amplified signal, and said playback module configured to receive a processed signal.
2. The wearable apparatus as recited in claim 1 further comprising a windscreen structure on said exterior surface of said at least one in-ear assembly.
3. The wearable apparatus as recited in claim 2 wherein said windscreen structure is disposed to partially enclose said microphone aperture, said tragus structure, and said antihelix structure.
4. The wearable apparatus as recited in claim 1 wherein said tragus structure is disposed to partially enclose said microphone aperture.
5. The wearable apparatus as recited in claim 1 wherein said antihelix structure is disposed to partially enclose said tragus structure and said microphone aperture.
6. The wearable apparatus as recited in claim 1 wherein said microphone channel comprises a length that is at least two times its diameter.
7. The wearable apparatus as recited in claim 1 wherein said isolation baffle achieves at least a 30 decibel noise isolation between said microphone and said playback module.
8. The wearable apparatus as recited in claim 1 wherein said microphone channel and said microphone are in a substantially parallel orientation relative to a listening direction of said user.
9. The wearable apparatus as recited in claim 1 further comprising a stabilizer assembly connected to said exterior of said at least one in-ear assembly.
10. The wearable apparatus as recited in claim 9 wherein said stabilizer assembly comprises a circular collar attached to said exterior of said at least one in-ear assembly, and a concha-shaped structure attached to said circular collar and structured for disposition on a user's ear when in said operative position.
11. A wearable apparatus for hearing enhancement and protection capable of generating a head related audio transfer function for a user, said wearable apparatus comprising: a left in-ear assembly and a right in-ear assembly disposable in an operative position, said left in-ear assembly and said right in-ear assembly each comprise of a primary chamber and a secondary chamber, said primary chamber disposed proximal to a user's ear and said secondary chamber disposed distal to a user's ear, when in said operative position, said secondary chamber comprises: a microphone aperture on an exterior surface of said secondary chamber, said microphone aperture in air flow communication with an external environment; a tragus structure on said exterior surface of said secondary chamber, said tragus structure disposed to partially enclose said microphone aperture, an antihelix structure on said exterior surface of said secondary chamber, said antihelix disposed to partially enclose said tragus structure and said microphone aperture, a microphone channel on an interior of said secondary chamber, said microphone channel in air flow communication with said microphone aperture, a microphone disposed within an end of said microphone channel, said primary chamber comprises: a playback module connected to said microphone, an auditory channel connected to said playback module, said auditory channel disposed in communication with a user's ear to convey the head related audio transfer function, when in said operative position, an isolation baffle disposed to isolate said microphone from said playback module, and a preamplifier configured to receive an audio signal, an audio processor configured to receive an amplified signal, and said playback module configured to receive a processed signal.
12. The wearable apparatus as recited in claim 11 further comprising a windscreen structure on said exterior surface of said secondary chamber.
13. The wearable apparatus as recited in claim 12 wherein said windscreen structure is disposed to partially enclose said microphone aperture, said tragus structure, and said antihelix structure.
14. The wearable apparatus as recited in claim 11 wherein said microphone channel comprises a length that is at least two times its diameter.
15. The wearable apparatus as recited in claim 11 wherein said isolation baffle achieves at least a 30 decibel noise isolation between said microphone and said playback module.
16. The wearable apparatus as recited in claim 11 wherein said microphone channel and said microphone are in a substantially parallel orientation relative to a listening direction of said user.
17. The wearable apparatus as recited in claim 11 further comprising a stabilizer assembly, said stabilizer comprising a circular collar connected to said exterior of said primary chamber, and a concha-shaped structure disposed on a user's ear, when in said operative position.
18. A wearable apparatus for hearing enhancement and protection capable of generating a head related audio transfer function for a user, said wearable apparatus comprising: at least one in-ear assembly disposable in an operative position, said at least one in-ear assembly comprising a primary chamber and a secondary chamber, said primary chamber disposed proximal to a user's ear and said secondary chamber disposed distal to a user's ear, when in said operative position, and an interconnecting member connected to said at least one in-ear assembly, said secondary chamber including: a microphone aperture on an exterior surface of said secondary chamber, said microphone aperture in air flow communication with the external environment; a tragus structure on said exterior surface of said secondary chamber, said tragus structure disposed to partially enclose said microphone aperture, an antihelix structure on said exterior surface of said secondary chamber, said antihelix disposed to partially enclose said tragus structure and said microphone aperture, a microphone channel on an interior of said secondary chamber, said microphone channel in air flow communication with said microphone aperture, a microphone attached to an end of said microphone channel, an isolation baffle disposed to isolate said microphone from a playback module; said primary chamber including: a playback module connected to said microphone, said playback module isolated from said microphone, an auditory channel connected to said playback module, said auditory channel disposed in communication with a user's ear to convey the head related audio transfer function, when in an operative position, a stabilizer assembly, said stabilizer comprising a circular collar connected to said exterior of said primary chamber, and a concha-shaped structure attached to said circular collar and structure for disposition on a user's ear, when in an operative position, said interconnecting member including: a flexible back section connected to a side section on one end and a side section on a second end, said interconnecting member connected to said at least one in-ear assembly, at least one audio processor configured to receive an audio signal from said at least one in-ear assembly, and at least one preamplifier configured to receive said audio signal, said audio processor further configured to receive an amplified signal, and said playback module configured to receive a processed signal.
19. The wearable apparatus as recited in claim 18 wherein said microphone channel and said microphone are in a substantially parallel orientation relative to a listening direction of a user.
20. The wearable apparatus as recited in claim 18 wherein said isolation baffle achieves at least a 30 decibel noise isolation between said microphone and said playback module.
21. The wearable apparatus as recited in claim 18 further comprising a windscreen structure on said exterior surface of said at least one in-ear assembly, disposed to partially enclose said microphone aperture, said tragus structure, and said antihelix structure.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) 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:
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(21) Like reference numerals refer to like parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE EMBODIMENT
(22) As illustrated by the accompanying drawings, the present invention is directed to an apparatus, system, and method for generating a head related audio transfer function for a user. Specifically, some embodiments relate to capturing surrounding sound in the external environment in real time, filtering that sound through unique structures formed on the apparatus in order to generate audio positional data, and then processing that sound to enhance and relay the positional audio data to a user, such that the user can determine the origination of the sound in three dimensional space.
(23) As schematically represented,
(24) The external manifold 110 may comprise a hexahedron shape having six faces. In at least one embodiment, the external manifold 110 is substantially cuboid. The external manifold 110 may comprise at least one surface that is concave or convex, such as an exterior surface exposed to the external environment. The internal manifold 120 may comprise a substantially cylindrical shape, which may be at least partially hollow. The external manifold 110 and internal manifold 120 may comprise sound dampening or sound proof materials, such as various foams, plastics, and glass known to those skilled in the art.
(25) Drawing attention to
(26) In at least one embodiment, the antihelix structure 101 comprises a partial dome structure having a closed side 105 and an open side 106. In a preferred embodiment, the open side 106 faces the preferred listening direction 104, and the closed side 105 faces away from the preferred listening direction 104. The tragus structure 102 may also comprise a partial dome structure having a closed side 107 and an open side 108. In a preferred embodiment, the open side 108 faces away from the preferred listening direction 104, while the closed side 107 faces towards the preferred listening direction 104. In other embodiments, the open side 106 of the antihelix structure 101 may be in direct confronting relation to the open side 108 of the tragus structure 102, regardless of the preferred listening direction 104.
(27) Partial dome as defined for the purposes of this document may comprise a half-dome structure or any combination of partial-dome structures. For instance, the anti-helix structure 101 of
(28) In at least one embodiment, the antihelix structure 101 and tragus structure 102 may be modular, such that different sizes or shapes (variations of different partial domes or partial-domes) may be swapped out based on a user's preference for particular acoustic characteristics.
(29) Drawing attention now to
(30) As previously discussed, the internal manifold 120 is formed wholly or substantially within an interior of the apparatus, such that it is not exposed directly to the outside air and will not be substantially affected by the external environment. In at least one embodiment, the auditory canal 121 formed within at least a portion of the internal manifold 121, will be disposed in a substantially parallel orientation relative to desired listening direction 104 of the user. In a preferred embodiment, the auditory canal comprises a length that is greater than two times its diameter.
(31) A microphone housing 122 is attached to an end of the auditory canal 121. Within the microphone housing 122, a microphone generally at 123, not shown, is mounted against the end of the auditory canal 121. In at least one embodiment, the microphone 123 is mounted flush against the auditory canal 121, such that the connection may be substantially air tight to avoid interference sounds. In a preferred embodiment, an air cavity generally at 124 is created behind the microphone and at the end of the internal manifold 120. This may be accomplished by inserting the microphone 123 into the microphone housing 122, and then sealing the end of the microphone housing, generally at 124, with a cap. The cap may be substantially air tight in at least one embodiment. Different gasses having different acoustic characteristics may be used within the air cavity.
(32) In at least one embodiment, apparatus 100 may form a part of a larger system 300 as illustrated in
(33) The left and right HRTF generators 100 and 100′ may comprise the apparatus 100 described above, each having unique structures such as the antihelix structure 101 and tragus structure 102. Accordingly, the HRTF generators 100/100′ may be structured to generate a head related audio transfer function for a user, such that the sound received by the HRTF generators 100/100′ may be relayed to the user to accurately communicate position data of the sound. In other words, the HRTF generators 100/100′ may replicate and replace the function of the user's own left and right ears, where the HRTF generators would collect sound, and perform respective spectral transformations or a filtering process to the incoming sounds to enable the process of vertical localization to take place.
(34) A left preamplifier 210 and right preamplifier 210′ may then be used to enhance the filtered sound coming from the HRTF generators, in order to enhance certain acoustic characteristics to improve locational accuracy, or to filter out unwanted noise. The preamplifiers 210/210′ may comprise an electronic amplifier, such as a voltage amplifier, current amplifier, transconductance amplifier, transresistance amplifier and/or any combination of circuits known to those skilled in the art for increasing or decreasing the gain of a sound or input signal. In at least one embodiment, the preamplifier comprises a microphone preamplifier configured to prepare a microphone signal to be processed by other processing modules. As it may be known in the art, microphone signals sometimes are too weak to be transmitted to other units, such as recording or playback devices with adequate quality. A microphone preamplifier thus increases a microphone signal to the line level by providing stable gain while preventing induced noise that might otherwise distort the signal.
(35) Audio processor 230 may comprise a digital signal processor and amplifier, and may further comprise a volume control. Audio processor 230 may comprise a processor and combination of circuits structured to further enhance the audio quality of the signal coming from the microphone preamplifier, such as but not limited to shelf filters, equalizers, modulators. For example, in at least one embodiment the audio processor 230 may comprise a processor that performs the steps for processing a signal as taught by the present inventor's U.S. Pat. No. 8,160,274, the entire disclosure of which is incorporated herein by reference. Audio processor 230 may incorporate various acoustic profiles customized for a user and/or for an environment, such as those described in the present inventor's U.S. Pat. No. 8,565,449, the entire disclosure of which is incorporated herein by reference. Audio processor 230 may additionally incorporate processing suitable for high noise environments, such as those described in the present inventor's U.S. Pat. No. 8,462,963, the entire disclosure of which is incorporated herein by reference. Parameters of the audio processor 230 may be controlled and modified by a user via any means known to one skilled in the art, such as by a direct interface or a wireless communication interface.
(36) The left playback module 230 and right playback module 230′ may comprise headphones, earphones, speakers, or any other transducer known to one skilled in the art. The purpose of the left and right playback modules 230/230′ is to convert the electrical audio signal from the audio processor 230 back into perceptible sound for the user. As such, a moving-coil transducer, electrostatic transducer, electret transducer, or other transducer technologies known to one skilled in the art may be utilized.
(37) In at least one embodiment, the present system 200 comprises a device 200 as generally illustrated at
(38) In a further embodiment as illustrated in
(39) In a preferred embodiment of the present invention, the method of
(40) In at least one embodiment, the method of
(41) With regard to
(42) The input device 1010 is at least partially structured or configured to transmit an input audio signal 2010, such as an amplified signal from a left or right preamplifier 210, 210′, into the system 1000 of the present invention, and in at least one embodiment into the high pass filter 1110.
(43) The high pass filter 1110 is configured to pass through high frequencies of an audio signal, such as the input signal 2010, while attenuating lower frequencies, based on a predetermined frequency. In other words, the frequencies above the predetermined frequency may be transmitted to the first filter module 3010 in accordance with the present invention. In at least one embodiment, ultra-low frequency content is removed from the input audio signal, where the predetermined frequency may be selected from a range between 300 Hz and 3 kHz. The predetermined frequency however, may vary depending on the source signal, and vary in other embodiments to comprise any frequency selected from the full audible range of frequencies between 20 Hz to 20 kHz. The predetermined frequency may be tunable by a user, or alternatively be statically set. The high pass filter 1110 may further comprise any circuits or combinations thereof structured to pass through high frequencies above a predetermined frequency, and attenuate or filter out the lower frequencies.
(44) The first filter module 3010 is configured to selectively boost or attenuate the gain of select frequency ranges within an audio signal, such as the high pass signal 2110. For example, and in at least one embodiment, frequencies below a first frequency may be adjusted by ±X dB, while frequencies above a first frequency may be adjusted by ±Y dB. In other embodiments, a plurality of frequencies may be used to selectively adjust the gain of various frequency ranges within an audio signal. In at least one embodiment, the first filter module 3010 may be implemented with a first low shelf filter 1120 and a first high shelf filter 1130, as illustrated in
(45) The first compressor 1140 is configured to modulate a signal, such as the first filtered signal 4010. The first compressor 1120 may comprise an automatic gain controller. The first compressor 1120 may comprise standard dynamic range compression controls such as threshold, ratio, attack and release. Threshold allows the first compressor 1120 to reduce the level of the filtered signal 2110 if its amplitude exceeds a certain threshold. Ratio allows the first compressor 1120 to reduce the gain as determined by a ratio. Attack and release determines how quickly the first compressor 1120 acts. The attack phase is the period when the first compressor 1120 is decreasing gain to reach the level that is determined by the threshold. The release phase is the period that the first compressor 1120 is increasing gain to the level determined by the ratio. The first compressor 1120 may also feature soft and hard knees to control the bend in the response curve of the output or modulated signal 2120, and other dynamic range compression controls appropriate for the dynamic compression of an audio signal. The first compressor 1120 may further comprise any device or combination of circuits that is structured and configured for dynamic range compression.
(46) The second filter module 3020 is configured to selectively boost or attenuate the gain of select frequency ranges within an audio signal, such as the modulated signal 2140. In at least one embodiment, the second filter module 3020 is of the same configuration as the first filter module 3010. Specifically, the second filter module 3020 may comprise a second low shelf filter 1150 and a second high shelf filter 1160. In certain embodiments, the second low shelf filter 1150 may be configured to filter signals between 100 Hz and 3000 Hz, with an attenuation of between −5 dB to −20 dB. In certain embodiments the second high shelf filter 1160 may be configured to filter signals between 100 Hz and 3000 Hz, with a boost of between +5 dB to +20 dB.
(47) The second filter module 3020 may be configured in at least a partially inverse configuration to the first filter module 3010. For instance, the second filter module may use the same frequency, for instance the first frequency, as the first filter module. Further, the second filter module may adjust the gain inversely to the gain or attenuation of the first filter module, of content above the first frequency. Similarly second filter module may also adjust the gain inversely to the gain or attenuation of the of the first filter module, of content below the first frequency. In other words, the purpose of the second filter module in one embodiment may be to “undo” the gain adjustment that was applied by the first filter module.
(48) The first processing module 3030 is configured to process a signal, such as the second filtered signal 4020. In at least one embodiment, the first processing module 3030 may comprise a peak/dip module, such as 1180 represented in
(49) The band splitter 1190 is configured to split a signal, such as the processed signal 4030. In at least one embodiment, the signal is split into a low band signal 2200, a mid band signal 2210, and a high band signal 2220. Each band may be the output of a fourth order section, which may be further realized as the cascade of second order biquad filters. In other embodiments, the band splitter may comprise any combination of circuits appropriate for splitting a signal into three frequency bands. The low, mid, and high bands may be predetermined ranges, or may be dynamically determined based on the frequency itself, i.e. a signal may be split into three even frequency bands, or by percentage. The different bands may further be defined or configured by a user and/or control mechanism.
(50) A low band compressor 1300 is configured to modulate the low band signal 2200, and a high band compressor 1310 is configured to modulate the high band signal 2220. In at least one embodiment, each of the low band compressor 1300 and high band compressor 1310 may be the same as the first compressor 1140. Accordingly, each of the low band compressor 1300 and high band compressor 1310 may each be configured to modulate a signal. Each of the compressors 1300, 1310 may comprise an automatic gain controller, or any combination of circuits appropriate for the dynamic range compression of an audio signal.
(51) A second processing module 3040 is configured to process at least one signal, such as the modulated low band signal 2300, the mid band signal 2210, and the modulated high band signal 2310. Accordingly, the second processing module 3040 may comprise a summing module 1320 configured to combine a plurality of signals. The summing module 1320 may comprise a mixer structured to combine two or more signals into a composite signal. The summing module 1320 may comprise any circuits or combination thereof structured or configured to combine two or more signals. In at least one embodiment, the summing module 1320 comprises individual gain controls for each of the incoming signals, such as the modulated low band signal 2300, the mid band signal 2210, and the modulated high band signal 2310. In at least one embodiment, the second processing module 3040 may further comprise a second gain element 1330. The second gain element 1330, in at least one embodiment, may be the same as the first gain element 1170. The second gain element 1330 may thus comprise an amplifier or multiplier circuit to adjust the signal, such as the combined signal, by a predetermined amount.
(52) The output device 1020 may comprise the left playback module 230 and/or right playback module 230′.
(53) As diagrammatically represented,
(54) Accordingly, an input audio signal, such as the amplified signal, is first filtered, as in 5010, with a high pass filter to create a high pass signal. The high pass filter is configured to pass through high frequencies of a signal, such as the input signal, while attenuating lower frequencies. In at least one embodiment, ultra-low frequency content is removed by the high-pass filter. In at least one embodiment, the high pass filter may comprise a fourth-order filter realized as the cascade of two second-order biquad sections. The reason for using a fourth order filter broken into two second order sections is that it allows the filter to retain numerical precision in the presence of finite word length effects, which can happen in both fixed and floating point implementations. An example implementation of such an embodiment may assume a form similar to the following: Two memory locations are allocated, designated as d(k−1) and d(k−2), with each holding a quantity known as a state variable. For each input sample x(k), a quantity d(k) is calculated using the coefficients a1 and a2:
d(k)=x(k)−a1*d(k−1)−a2*d(k−2) The output y(k) is then computed, based on coefficients b0, b1, and b2, according to:
y(k)=b0*d(k)+b1*d(k−1)+b2*d(k−2)
(55) The above computation comprising five multiplies and four adds is appropriate for a single channel of second-order biquad section. Accordingly, because the fourth-order high pass filter is realized as a cascade of two second-order biquad sections, a single channel of fourth order input high pass filter would require ten multiples, four memory locations, and eight adds.
(56) The high pass signal from the high pass filter is then filtered, as in 5020, with a first filter module to create a first filtered signal. The first filter module is configured to selectively boost or attenuate the gain of select frequency ranges within an audio signal, such as the high pass signal. Accordingly, the first filter module may comprise a second order low shelf filter and a second order high shelf filter in at least one embodiment. In at least one embodiment, the first filter module boosts the content above a first frequency by a certain amount, and attenuates the content below a first frequency by a certain amount, before presenting the signal to a compressor or dynamic range controller. This allows the dynamic range controller to trigger and adjust higher frequency material, whereas it is relatively insensitive to lower frequency material.
(57) The first filtered signal from the first filter module is then modulated, as in 5030, with a first compressor. The first compressor may comprise an automatic or dynamic gain controller, or any circuits appropriate for the dynamic compression of an audio signal. Accordingly, the compressor may comprise standard dynamic range compression controls such as threshold, ratio, attack and release. An example implementation of the first compressor may assume a form similar to the following: The compressor first computes an approximation of the signal level, where att represents attack time; rel represents release time; and invThr represents a precomputed threshold:
(58) TABLE-US-00001 temp = abs(x(k)) if temp > level (k-1) level(k) = att * (level(k-1) − temp) + temp else level = rel * (level(k-1) − temp) + temp This level computation is done for each input sample. The ratio of the signal's level to invThr then determines the next step. If the ratio is less than one, the signal is passed through unaltered. If the ratio exceeds one, a table in the memory may provide a constant that's a function of both invThr and level:
(59) TABLE-US-00002 if (level * thr < 1) output(k) = x(k) else index = floor(level * invThr) if (index > 99) index = 99 gainReduction = table[index] output(k) = gainReduction * x(k)
(60) The modulated signal from the first compressor is then filtered, as in 5040, with a second filter module to create a second filtered signal. The second filter module is configured to selectively boost or attenuate the gain of select frequency ranges within an audio signal, such as the modulated signal. Accordingly, the second filter module may comprise a second order low shelf filter and a second order high shelf filter in at least one embodiment. In at least one embodiment, the second filter module boosts the content above a second frequency by a certain amount, and attenuates the content below a second frequency by a certain amount. In at least one embodiment, the second filter module adjusts the content below the first specified frequency by a fixed amount, inverse to the amount that was removed by the first filter module. By way of example, if the first filter module boosted content above a first frequency by +X dB and attenuated content below a first frequency by −Y dB, the second filter module may then attenuate the content above the first frequency by −X dB, and boost the content below the first frequency by +Y dB. In other words, the purpose of the second filter module in one embodiment may be to “undo” the filtering that was applied by the first filter module.
(61) The second filtered signal from the second filter module is then processed, as in 5050, with a first processing module to create a processed signal. The processing module may comprise a gain element configured to adjust the level of the signal. This adjustment, for instance, may be necessary because the peak-to-average ratio was modified by the first compressor. The processing module may comprise a peak/dip module. The peak/dip module may comprise ten cascaded second-order filters in at least one embodiment. The peak/dip module may be used to shape the desired output spectrum of the signal. In at least one embodiment, the first processing module comprises only the peak/dip module. In other embodiments, the first processing module comprises a gain element followed by a peak/dip module.
(62) The processed signal from the first processing module is then split, as in 5060, with a band splitter into a low band signal, a mid band signal, and a high band signal. The band splitter may comprise any circuit or combination of circuits appropriate for splitting a signal into a plurality of signals of different frequency ranges. In at least one embodiment, the band splitter comprises a fourth-order band-splitting bank. In this embodiment, each of the low band, mid band, and high band are yielded as the output of a fourth-order section, realized as the cascade of second-order biquad filters.
(63) The low band signal is modulated, as in 5070, with a low band compressor to create a modulated low band signal. The low band compressor may be configured and/or computationally identical to the first compressor in at least one embodiment. The high band signal is modulated, as in 5080, with a high band compressor to create a modulated high band signal. The high band compressor may be configured and/or computationally identical to the first compressor in at least one embodiment.
(64) The modulated low band signal, mid band signal, and modulated high band signal are then processed, as in 5090, with a second processing module. The second processing module comprises at least a summing module. The summing module is configured to combine a plurality of signals into one composite signal. In at least one embodiment, the summing module may further comprise individual gain controls for each of the incoming signals, such as the modulated low band signal, the mid band signal, and the modulated high band signal. By way of example, an output of the summing module may be calculated by:
out=w0*low+w1*mid+w2*high
The coefficients w0, w1, and w2 represent different gain adjustments. The second processing module may further comprise a second gain element. The second gain element may be the same as the first gain element in at least one embodiment. The second gain element may provide a final gain adjustment. Finally, the second processed signal is transmitted as the output signal.
(65) As diagrammatically represented,
(66) Accordingly, an input audio signal is first filtered, as in 5010, with a high pass filter. The high pass signal from the high pass filter is then filtered, as in 6010, with a first low shelf filter. The signal from the first low shelf filter is then filtered with a first high shelf filter, as in 6020. The first filtered signal from the first low shelf filter is then modulated with a first compressor, as in 5030. The modulated signal from the first compressor is filtered with a second low shelf filter as in 6110. The signal from the low shelf filter is then filtered with a second high shelf filter, as in 6120. The second filtered signal from the second low shelf filter is then gain-adjusted with a first gain element, as in 6210. The signal from the first gain element is further processed with a peak/dip module, as in 6220. The processed signal from the peak/dip module is then split into a low band signal, a mid band signal, and a high band signal, as in 5060. The low band signal is modulated with a low band compressor, as in 5070. The high band signal is modulated with a high band compressor, as in 5080. The modulated low band signal, mid band signal, and modulated high band signal are then combined with a summing module, as in 6310. The combined signal is then gain adjusted with a second gain element in order to create the output signal, as in 6320.
(67) It should be understood that the above steps may be conducted exclusively or nonexclusively and in any order. Further, the physical devices recited in the methods may comprise any apparatus and/or systems described within this document or known to those skilled in the art.
(68) 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 equivalents.
(69) In one preferred embodiment,
(70) The in-ear assembly 400 comprises at least one chamber, shell, or chassis, which houses the various structures on the interior of the in-ear assembly 400, and provides exterior surfaces to house the structures that mimic the functions of a human ear for generating a head related audio transfer function (“HRTF”). Drawing attention to the embodiment in
(71) As illustrated in
(72) Drawing attention to
(73) As illustrated in
(74) In a preferred embodiment, as illustrated in
(75) As illustrated in
(76) As illustrated in
(77) Drawing attention now to
(78) The microphone channel 412 can be disposed in a substantially parallel orientation relative to the desired listening direction 104 of the user when the ear-in assembly 400 is worn by a user, generally illustrated in
(79) Drawing attention to
(80) Drawing further attention to
(81) Furthermore, as illustrated in
(82) In a preferred embodiment, the at least one in-ear assembly 400 also comprises the previously mentioned preamplifier 210 and audio processor 220, as schematically illustrated in
(83) The audio processor 220 may comprise a digital signal processor and amplifier, and may further comprise a volume control. Audio processor 220 may comprise a processor and combination of circuits structured to further enhance the audio quality of the signal coming from the microphone preamplifier, such as but not limited to shelf filters, equalizers, modulators. For example, in at least one embodiment the audio processor 220 may comprise a processor that performs the steps for processing a signal as taught by the present inventor's U.S. Pat. No. 8,160,274, the entire disclosure of which is incorporated herein by reference. Audio processor 220 may incorporate various acoustic profiles customized for a user and/or for an environment, such as those described in the present inventor's U.S. Pat. No. 8,565,449, the entire disclosure of which is incorporated herein by reference. Audio processor 220 may additionally incorporate processing suitable for high noise environments, such as those described in the present inventor's U.S. Pat. No. 8,462,963, the entire disclosure of which is incorporated herein by reference. Parameters of the audio processor 220 may be controlled and modified by a user via any means known to one skilled in the art, such as by a direct interface or a wireless communication interface.
(84) In another embodiment as illustrated in
(85) 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 equivalents.