System and methods for objective evaluation of hearing using auditory steady-state responses

A method of testing the hearing of a subject, wherein said method comprises the steps of:

• (a) creating an optimum-vector mixed modulation test signal comprising at least one signal having an amplitude modulated component with a first phase and a frequency modulated component with a second phase wherein said second phase is adjusted relative to said first phase to evoke an increased response from said subject;
• (b) transducing said test signal to create an acoustic stimulus and presenting said acoustic stimulus to said subject;
• (c) sensing potentials from said subject while substantially simultaneously presenting said acoustic stimulus to said subject;
• and,
• (d) analyzing said potentials to determine whether said potentials comprise data indicative of the presence of at least one steady-state response to said acoustic stimulus.

A method of testing the hearing of a subject, wherein said method comprises the steps of:

• (a) creating a test signal comprising at least one independent amplitude modulated and frequency modulated signal having an amplitude modulated component and a frequency modulated component, wherein said amplitude modulated component comprises a first modulation frequency and a first carrier frequency and said frequency modulated component comprises a second modulation frequency and a second carrier frequency wherein said first modulation frequency is substantially different from said second modulation frequency and said first carrier frequency is substantially similar to said second carrier frequency;
• (b) transducing said test signal to create an acoustic stimulus and presenting said acoustic stimulus to said subject;
• (c) sensing potentials from said subject while substantially simultaneously presenting said acoustic stimulus to said subject;
• and,
• (d) analyzing said potentials to determine whether said potentials comprise data indicative of a steady-state response to each amplitude modulated component and a steady-state response to each frequency modulated component.

An apparatus for testing the hearing of a subject, wherein said apparatus comprises:

• (a) a signal creator adapted to create a test signal comprising at least one combined amplitude modulated and frequency modulated signal having an amplitude modulated component with a first phase and a frequency modulated component with a second phase wherein said signal creator comprises means for adjusting said second phase relative to said first phase;
• (b) a transducer electrically coupled to said processor and adapted to transduce said test signal to create an acoustic stimulus and present said acoustic stimulus to said subject;
• (c) a sensor adapted to sense potentials from said subject while said acoustic stimulus is substantially simultaneously presented to said subject;
• and,
• (d) a processor electrically coupled to said sensor and adapted to receive said potentials and analyze said potentials to determine if said potentials comprise data indicative of at least one response to said acoustic stimulus.

A method of analyzing potentials to determine whether said potentials comprise data indicative of the presence of at least one steady-state response to a steady-state evoked potential stimulus, wherein said method comprises the steps of:

• (a) presenting an evoked potential stimulus to a subject;
• (b) sensing potentials from said subject while substantially simultaneously presenting said stimulus to said subject to obtain a plurality of data points;
• (c) transforming said plurality of data points into a second plurality of data points;
• (d) biasing said second plurality of data points with an expected phase value to obtain a plurality of biased data points;
• and,
• (e) applying a statistical test to said plurality of biased data points to detect said response.

A method of detecting a response to an evoked potential stimulus, wherein said method comprises the steps of:

• (a) presenting an evoked potential stimulus to a subject;
• (b) sensing potentials from said subject while substantially simultaneously presenting said stimulus to said subject to obtain a plurality of data points;
• and,
• (c) calculating phase values for said plurality of data points, wherein, a response is detected if an adequate number of said calculated phase values fall within a predetermined phase value range.

An apparatus for testing the hearing of a subject, wherein said apparatus comprises:

• (a) a signal creator adapted to create a test signal;
• (b) a transducer electrically coupled to said signal creator and adapted to transduce said test signal to create an acoustic stimulus and present said acoustic stimulus to said subject;
• (c) a sensor adapted to sense potentials from said subject while said acoustic stimulus is substantially simultaneously presented to said subject;
• and,
• (d) a processor electrically coupled to said sensor and adapted to receive said potentials and analyze said potentials to determine if said potentials comprise data indicative of at least one response to said acoustic stimulus;
• wherein said analysis involves biasing said potentials based on an expected phase value.

A method of noise reduction for a plurality of data points which are obtained during steady-state evoked potential testing, wherein said plurality of data points comprise at least one signal and noise and wherein said method comprises the steps of:

• (a) obtaining said plurality of data points;
• (b) separating said plurality of data points into a plurality of epochs;
• and,
• (c) applying an adaptive noise reduction method to each epoch.

A method of objectively testing the hearing of a subject, wherein said method comprises the steps of:

• (a) selecting an auditory test;
• (b) creating an appropriate test signal comprising at least one component for said auditory test;
• (c) transducing said test signal to create a stimulus and presenting said stimulus to said subject;
• (d) sensing potentials from said subject while substantially simultaneously presenting said stimulus to said subject;
• and,
• (e) analyzing said potentials to detect at least one response.

An apparatus for objectively testing the hearing of a subject, wherein said apparatus comprises:

• (a) a selector adapted for selecting an auditory test to perform on said subject;
• (b) a signal creator electrically coupled to said selector and adapted to create an appropriate test signal comprising at least one component for said test;
• (c) a transducer electrically coupled to said signal creator and adapted to transduce said test signal to create an acoustic stimulus and present said acoustic stimulus to said subject;
• (d) a sensor adapted to sense potentials from said subject while said acoustic stimulus is substantially simultaneously presented to said subject;
• (e) a processor electrically coupled to said sensor and adapted to receive said potentials and analyze said potentials to determine if said potentials comprise data indicative of at least one response to said acoustic stimulus;
• and,
• (f) a programmable hearing aid coupled to said processor, wherein, said programmable hearing aid comprises a plurality of programmable gain factors for different frequency regions and at least one programmable filter slope.

A method of testing at least two senses of a subject, wherein said method comprises the steps of:

• (a) selecting a first steady-state test signal to test a first sensory modality;
• (b) transducing said first steady-state test signal to create a first stimulus and presenting said first stimulus to said subject;
• (c) selecting a second steady-state test signal to test a second sensory modality;
• (d) transducing said second steady-state test signal to create a second stimulus and presenting said second stimulus to said subject;
• (e) sensing potentials while substantially simultaneously presenting both stimuli to said subject;
• and,
• (f) analyzing said potentials to determine whether said potentials comprise data indicative of at least one steady-state response to said stimuli.

An apparatus for testing at least two senses of a subject, wherein said apparatus comprises:

• (a) a signal creator adapted to create a first steady-state test signal and a second steady-state test signal;
• (b) a first transducer electrically coupled to said selector and adapted to transduce said first test signal to create a first stimulus and present said first stimulus to said subject;
• (c) a second transducer electrically coupled to said selector and adapted to transduce said second test signal to create a second stimulus and present said second stimulus to said subject;
• (d) a first sensor adapted to sense first potentials from said subject while said first stimulus is substantially simultaneously presented to said subject;
• (e) a second sensor adapted to sense second potentials from said subject while said second stimulus is substantially simultaneously presented to said subject;
• (f) a processor electrically coupled to said first sensor and adapted to receive said first potentials and analyze said first potentials to determine if said first potentials comprise data indicative of at least one response to said first stimulus;
• and,
• (g) the processor, electrically coupled to said second sensor and adapted to receive said second potentials and analyze said second potentials to determine if said second potentials comprise data indicative of at least one response to said second stimulus, wherein, each stimulus is presented substantially simultaneously.