System and method for measuring acoustic reflectance
First Claim
1. A system for the measurement of a linear response of the ear, the system comprising:
- a probe assembly positionable in the ear;
an acoustic source within said probe assembly to produce an acoustic stimulus in response to an electrical input signal;
an acoustic energy detector within said probe assembly to detect acoustic energy signals and convert said detected acoustic energy signals to detected electrical signals;
one or more acoustic calibration waveguides, each having predetermined dimensions and having first and second ends;
a stimulus signal generator coupled to said acoustic source to generate said electrical input signal when said probe assembly is positioned in said first end of said one or more acoustic calibration waveguides, said stimulus signal generator also generating said electrical input signal when said probe assembly is positioned in the ear;
a signal processor receiving a set of detected calibration electrical signals from said acoustic energy detector when said probe assembly is positioned in each of said one or more acoustic calibration waveguides and receiving a detected measurement electrical signal when said probe assembly is positioned in the ear; and
a computer processor containing a calibration waveguide model indicative of an acoustic transfer characteristic, including viscothermal effects, for each of said one or more acoustic calibration waveguides, said computer processor determining a linear response function of the ear based on said set of detected calibration electrical signals, detected measurement electrical signal and said calibration waveguide model.
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Accused Products
Abstract
A system and method of measuring the linear and nonlinear power-based responses of the ear uses a small probe assembly containing a sound source and microphone inserted into the ear. The linear power-based responses, or transfer functions, measured by the system include reflectance, admittance and impedance calculated in the time and frequency domains. A calibration procedure is based upon measured pressure responses in one or more calibration waveguides, and upon a model of the transfer function of each of the calibration waveguides that incorporates viscothermal losses. The linear transfer functions and the measured pressure responses in the ear may be combined to calculate sound power absorbed by the ear. The system is further able to measure the corresponding nonlinear power-based response of the ear by measuring any of the above transfer functions at different levels of the acoustic stimulus. These are used to calculate the nonlinear power absorbed by the ear when combined with the measured pressure responses in the ear at each stimulus level. A differential nonlinear transfer function of the ear and differential power absorbed by the ear are calculated based upon the level-dependent measurements of the transfer functions and the absorbed power. By delivering changes in static pressure applied to the ear via an additional probe tube in the probe assembly, the system is able to measure the dependence on static pressure of any of these linear and nonlinear power-based functions. The system is particularly useful in testing the auditory response of the human ear, with applications to the detection and diagnosis of abnormalities in the external, middle and inner ear of humans ranging in age from neonates to adults, as well as to the better understanding of the threshold audibility function in normal and hearing-impaired humans.
88 Citations
116 Claims
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1. A system for the measurement of a linear response of the ear, the system comprising:
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a probe assembly positionable in the ear; an acoustic source within said probe assembly to produce an acoustic stimulus in response to an electrical input signal; an acoustic energy detector within said probe assembly to detect acoustic energy signals and convert said detected acoustic energy signals to detected electrical signals; one or more acoustic calibration waveguides, each having predetermined dimensions and having first and second ends; a stimulus signal generator coupled to said acoustic source to generate said electrical input signal when said probe assembly is positioned in said first end of said one or more acoustic calibration waveguides, said stimulus signal generator also generating said electrical input signal when said probe assembly is positioned in the ear; a signal processor receiving a set of detected calibration electrical signals from said acoustic energy detector when said probe assembly is positioned in each of said one or more acoustic calibration waveguides and receiving a detected measurement electrical signal when said probe assembly is positioned in the ear; and a computer processor containing a calibration waveguide model indicative of an acoustic transfer characteristic, including viscothermal effects, for each of said one or more acoustic calibration waveguides, said computer processor determining a linear response function of the ear based on said set of detected calibration electrical signals, detected measurement electrical signal and said calibration waveguide model. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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45. A system for the measurement of a nonlinear power-based transfer function of the ear, the system comprising:
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a probe assembly positionable in the ear; an acoustic source within said probe assembly to produce an acoustic stimulus in response to an electrical input signal; an acoustic energy detector within said probe assembly to detect acoustic energy signals and convert said detected acoustic energy signals to detected electrical signals; a stimulus signal generator coupled to said acoustic source to generate said electrical input signal at first and second stimulus levels to cause said acoustic source to produce acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; a pump coupled to said probe assembly to control static pressure in the ear; a signal processor to receive detected measurement electrical signals in response to said acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; and a computer processor determining a first power-based transfer function of the ear as a function of said static pressure based on a detected measurement electrical signal in response to said acoustic stimulus at said first acoustic stimulus level and measurement system parameters of said probe assembly, determining a second power-based transfer function of the ear as a function of said static pressure based on a detected measurement electrical signal in response to said acoustic stimulus at said second acoustic stimulus level and measurement system parameters of said probe assembly, said computer processor further determining the power-based nonlinear transfer function based on said first and second transfer functions of the ear and said static pressure. - View Dependent Claims (46, 47)
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48. A system for the measurement of a nonlinear power-based transfer function of the ear, the system comprising:
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one or more acoustic calibration waveguides, each having predetermined dimensions and having first and second ends; a probe assembly positionable in the ear; an acoustic source within said probe assembly to produce an acoustic stimulus in response to an electrical input signal; an acoustic energy detector within said probe assembly to detect acoustic energy signals and convert said detected acoustic energy signals to detected electrical signals; a stimulus signal generator coupled to said acoustic source to generate said electrical input signal when said probe assembly is positioned in said first end of said one or more acoustic calibration waveguides, said stimulus signal generator also generating said electrical input signal at first and second stimulus levels to cause said acoustic source to produce acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; a pump coupled to said probe assembly to control static pressure in the ear; a signal processor to receive a set of detected calibration electrical signals from said acoustic energy detector when said probe assembly is positioned in each of said one or more acoustic calibration waveguides and receiving detected measurement electrical signals in response to said acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; and a computer processor containing a calibration waveguide model indicative of an acoustic transfer characteristic for each of said one or more acoustic calibration waveguides, said computer processor determining first and second power-based transfer functions of the ear as a function of said static pressure based on said detected measurement electrical signals in response to said acoustic stimuli at said first and second acoustic stimulus levels, respectively, said set of detected calibration electrical signals, and said acoustic calibration waveguide model, said computer processor further determining the power-based nonlinear transfer function based on said first and second transfer functions of the ear and said static pressure. - View Dependent Claims (49, 50, 51)
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52. A system for the measurement of a power absorbed by the ear, the system comprising:
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a probe assembly positionable in the ear; an acoustic source within said probe assembly to produce an acoustic stimulus in response to an electrical input signal; an acoustic energy detector within said probe assembly to detect acoustic energy signals and convert said detected acoustic energy signals to detected electrical signals; a stimulus signal generator coupled to said acoustic source to generate said electrical input signal at first and second stimulus levels to cause said acoustic source to produce acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; a signal processor to receive detected measurement electrical signals in response to said acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; and a computer processor determining a first power-based transfer function of the ear based on a first detected measurement electrical signal in response to said acoustic stimulus at said first acoustic stimulus level, determining a second power-based transfer function of the ear based on a second detected measurement electrical signal in response to said acoustic stimulus at said second acoustic stimulus level, said computer processor further determining the power absorbed by the ear at said first and second acoustic stimuli levels based on said first and second transfer functions and said first and second detected measurement electrical signals. - View Dependent Claims (53, 54, 55, 56, 57)
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58. A system for the measurement of a nonlinear power-based transfer function of the ear, the system comprising:
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a probe assembly positionable in the ear; an acoustic source within said probe assembly to produce an acoustic stimulus in response to an electrical input signal; an acoustic energy detector within said probe assembly to detect acoustic energy signals and convert said detected acoustic energy signals to detected electrical signals; one or more acoustic calibration waveguides, each having predetermined dimensions and having first and second ends; a stimulus signal generator coupled to said acoustic source to generate said electrical input signal when said probe assembly is positioned in said first end of said one or more acoustic calibration waveguides, said stimulus signal generator also generating said electrical input signal at first and second stimulus levels to cause said acoustic source to produce acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; a signal processor to receive a set of detected calibration electrical signals from said acoustic energy detector when said probe assembly is positioned in each of said one or more acoustic calibration waveguides and to receive detected measurement electrical signals in response to said acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; and a computer processor containing a calibration waveguide model indicative of an acoustic transfer characteristic, including viscothermal effects, for each of said one or more acoustic calibration waveguides, said computer processor determining a first power-based transfer function of the ear based on said set of detected calibration electrical signals, said detected measurement electrical signals in response to said acoustic stimulus at said first acoustic stimulus level, and said calibration waveguide model, determining a second power-based transfer function of the ear based on said set of detected calibration electrical signals, said detected measurement electrical signals in response to said acoustic stimulus at said second acoustic stimulus level, and said calibration waveguide model, said computer processor further determining the power-based nonlinear transfer function based on said first and second transfer functions. - View Dependent Claims (59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77)
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78. A system for the measurement of a reflectance of the ear, the system comprising:
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a probe assembly positionable in the ear; an acoustic source within said probe assembly to produce an acoustic stimulus in response to an electrical input signal; an acoustic energy detector within said probe assembly to detect acoustic energy signals and convert said detected acoustic energy signals to detected electrical signals; a stimulus signal generator coupled to said acoustic source to generate said electrical input signal when said probe assembly is positioned in the ear; a pump coupled to said probe assembly to control static pressure in the ear; a signal processor receiving a detected electrical signal when said probe assembly is positioned in the ear, said signal processor calculating a transfer function of the ear as a function of said static pressure; a storage area containing an estimate of an ear canal area; and a computer processor receiving said transfer function and said ear canal estimate from said storage area, said computer processor calculating the reflectance of the ear as a function of said static pressure. - View Dependent Claims (79, 80, 81)
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82. A method for the measurement of a linear response of the ear, the method comprising the steps of:
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positioning a probe assembly in one or more acoustic calibration waveguides, each having predetermined dimensions and having first and second ends; generating an electrical input signal to an acoustic source within said probe assembly when said probe assembly is positioned in said first end of said one or more acoustic calibration waveguides to produce an acoustic stimulus in response to said electrical input signal; detecting acoustic energy signals with an acoustic energy detector within said probe assembly and converting said detected acoustic energy signals to detected electrical signals; receiving a set of detected calibration electrical signals from said acoustic energy detector when said probe assembly is positioned in each of said one or more acoustic calibration waveguides; positioning said probe assembly in the ear; generating said electrical input signal when said probe assembly is positioned in the ear; receiving a detected measurement electrical signal when said probe assembly is positioned in the ear; and determining a linear response function of the ear based on said set of detected calibration electrical signals and detected measurement electrical signal and a calibration waveguide model indicative of an acoustic transfer characteristic, including viscothermal effects, for each of said one or more acoustic calibration waveguides. - View Dependent Claims (83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106)
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107. A method for the measurement of a nonlinear power-based transfer function of the ear, the method comprising the steps of:
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positioning a probe assembly in one or more acoustic calibration waveguides, each having predetermined dimensions and first and second ends; generating electrical input signals for an acoustic source within said probe assembly when said probe assembly is positioned in said first end of said one or more acoustic calibration waveguides to produce acoustic stimuli in response to said electrical input signals; detecting acoustic energy signals with an acoustic energy detector within said probe assembly and converting said detected acoustic energy signals to detected calibration electrical signals; receiving said set of detected calibration electrical signals from said acoustic energy detector when said probe assembly is positioned in each of said one or more acoustic calibration waveguides; positioning said probe assembly in the ear; generating said electrical input signal at first and second levels to cause said acoustic source to produce acoustic stimuli at first and second acoustic stimulus levels, respectively, when said probe assembly is positioned in the ear; receiving first and second detected measurement electrical signals in response to said acoustic stimuli at first and second acoustic stimulus levels, respectively, when said probe assembly is positioned in the ear; determining a first power-based transfer function of the ear based on said set of detected calibration electrical signals in said one or more acoustic calibration waveguides, said first detected measurement electrical signal, and a calibration waveguide model indicative of an acoustic transfer characteristic, including viscothermal effects, for each of said one or more acoustic calibration waveguides; determining a second power-based transfer function of the ear based on said set of detected calibration electrical signals in said one or more acoustic calibration waveguides, said second detected measurement electrical signal, and said calibration waveguide model; and determining the nonlinear power-based transfer function of the ear based on said first and second transfer functions.
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108. A method for the measurement of a nonlinear power-based transfer function of the ear, the system comprising:
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positioning a probe assembly in the ear; generating an electrical input signal at first and second stimulus levels to produce acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; varying static pressure in the ear in a controlled fashion; receiving first and second detected measurement electrical signals in response to said acoustic stimuli at first and second acoustic stimulus levels, respectively, when said probe assembly is positioned in the ear; determining a first power-based transfer function of the ear of the ear as a function of said static pressure based on said first detected measurement electrical signal and measurement system parameters of said probe assembly; determining a second power-based transfer function of the ear of the ear as a function of said static pressure based on said second detected measurement electrical signal and said measurement system parameters; and determining the power-based nonlinear transfer function based on said first and second transfer functions of the ear and said static pressure.
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109. A method for the measurement of a nonlinear power-based transfer function of the ear, the method comprising the steps of:
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positioning a probe assembly in one or more acoustic calibration waveguides, each having predetermined dimensions and first and second ends; generating electrical input signals for an acoustic source within said probe assembly when said probe assembly is positioned in said first end of said one or more acoustic calibration waveguides to produce acoustic stimuli in response to said electrical input signals; detecting acoustic energy signals with an acoustic energy detector within said probe assembly and converting said detected acoustic energy signals to detected calibration electrical signals; receiving said set of detected calibration electrical signals from said acoustic energy detector when said probe assembly is positioned in each of said one or more acoustic calibration waveguides; positioning a probe assembly in the ear; varying static pressure in the ear in a controlled fashion; generating said electrical input signal at first and second levels to cause said acoustic source to produce acoustic stimuli at first and second acoustic stimulus levels, respectively, when said probe assembly is positioned in the ear; receiving detected measurement electrical signals in response to said acoustic stimuli at first and second acoustic stimulus levels when said probe assembly is positioned in the ear; determining a first power-based transfer function of the ear as a function of said static pressure based on said set of detected calibration electrical signals in said one or more acoustic calibration waveguides, said detected measurement electrical signals in response to said acoustic stimulus at said first acoustic stimulus level, and a calibration waveguide model indicative of an acoustic transfer characteristic for each of said one or more acoustic calibration waveguides; determining a second power-based transfer function of the ear as a function of said static pressure based on said set of detected calibration electrical signals in said one or more acoustic calibration waveguides, said detected measurement electrical signals in response to said acoustic stimulus at said second acoustic stimulus level, and said calibration waveguide model for each of said one or more acoustic calibration waveguides; and determining the nonlinear power-based transfer function of the ear based on said first and second transfer functions and said static pressure.
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110. A method for the measurement of a power absorbed by the ear, the method comprising the steps of:
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positioning a probe assembly in the ear; generating an electrical input signal at first and second levels to cause an acoustic source within said probe assembly to produce acoustic stimuli at first and second acoustic stimulus levels, respectively, when said probe assembly is positioned in the ear; detecting acoustic energy signals and converting said detected acoustic energy signals to detected electrical signals; receiving first and second detected measurement electrical signals in response to said acoustic stimuli at first and second acoustic stimulus levels, respectively, when said probe assembly is positioned in the ear; determining a first power-based transfer function of the ear based on said first detected measurement electrical signal; determining a second power-based transfer function of the ear based on said second detected measurement electrical signal; and determining the power absorbed by the ear at said first and second acoustic stimuli levels based on said first and second transfer functions and said first and second detected measurement electrical signals. - View Dependent Claims (111, 112)
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113. A method for the measurement of a reflectance of the ear, the system comprising:
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positioning a probe assembly in the ear; generating an electrical input signal to an acoustic source within said probe assembly to produce an acoustic stimulus in response to said electrical input signal; receiving a detected measurement electrical signal when said probe assembly is positioned in the ear; varying static pressure in the ear in a controlled fashion; calculating a transfer function of the ear as a function of said static pressure; estimating an ear canal area; and receiving said transfer function and said ear canal area estimate and calculating therefrom the reflectance of the ear as a function of said static pressure. - View Dependent Claims (114, 115, 116)
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Specification