Hearing event related potential system for adaptive hearing threshold

Abstract

The invention relates to an auditory event related potential system of a self-adaptive hearing threshold, and the system comprises an acoustic stimulation module which is used for generating an adjustable sound pressure stimulation signal with the carrier frequency of 500-4000 Hz and the modulation frequency of 35-110 Hz; the electroencephalogram acquisition module is used for acquiring electroencephalogram signals of a subject in real time; the neural response detection module is used for performing spectral analysis on the electroencephalogram signals and calculating the signal-to-noise ratio SNR at the modulation frequency, namely SNRgt; when a threshold value is set, judging that neural response exists; the self-adaptive threshold value adjusting module is used for iteratively adjusting the sound pressure level based on the neural response result and determining the sound pressure level of the lowest extraction response as a hearing threshold value; and the ERP parameter calibration module is used for automatically setting an ERP stimulation sound pressure level according to the hearing threshold value. The system is a system which does not need subjective cooperation of a subject, can automatically measure a hearing threshold value and is used for ERP stimulation parameter calibration, so that the problems of subjective stimulation intensity setting, neglect of individual differences, poor data quality, difficulty in being suitable for special crowds and the like in an existing ERP system are solved.

Description

Technical Field

[0001] This invention relates to the field of neurophysiological detection technology, and in particular to an auditory event-related potential (ERP) system with adaptive hearing thresholds. It is an automatic hearing threshold calibration system for the preparation phase of an ERP system, and is especially suitable for the technology of personalized automatic calibration of auditory stimulation parameters of subjects in clinical medical care, rehabilitation medicine and cognitive neuroscience research. Background Technology

[0002] Event-related potentials (ERPs) are an objective neurophysiological indicator widely used in neuroscience research and clinical diagnosis. They are commonly used to assess cognitive function (such as attention, memory, and state of consciousness) and clinical disorders (such as disorders of consciousness, hearing impairment, autism, ADHD, etc.).

[0003] Currently, most medical and research institutions use fixed or subjectively experienced stimulation volumes (such as 60dB or 70dB) in their ERP systems when conducting auditory-related ERP experiments, failing to consider the significant differences in auditory thresholds between individuals. This non-personalized setting leads to inconsistent ERP signal strength among different subjects, excessive inter-group differences, reduced signal-to-noise ratio (SNR) of the ERP experiment, and consequently affects the reliability and validity of the experimental results.

[0004] Many ERP experiment participants are not standard healthy individuals, but rather patients receiving treatment in hospitals, infants (who have difficulty subjectively observing hearing), the elderly (who often have hearing loss), patients with impaired consciousness, patients with mental illness (who have difficulty subjectively cooperating), or people with implicit hearing loss (such as high-frequency hearing loss but who perceive themselves as normal). These individuals may not be able to hear the conventionally designed sound stimuli, leading to ERP induction failure.

[0005] The current technical drawbacks of auditory stimulation for ERP systems include:

[0006] 1. The stimulation volume did not take into account individual differences, resulting in insufficient stimulation for some subjects and an excessively small ERP response amplitude;

[0007] 2. Excessive sound stimulation in some hearing-sensitive subjects can affect the stability of ERP data;

[0008] 3. Poor reproducibility of ERP data between or within groups reduces the objectivity of ERP diagnosis or research;

[0009] 4. It cannot achieve rapid and personalized hearing threshold calibration and lacks objective standards.

[0010] In summary, existing technologies neglect individual hearing differences and the limitations of special populations, resulting in unscientific ERP stimulation parameter settings, low data quality, and a lack of efficient and objective calibration mechanisms. Summary of the Invention

[0011] To address the shortcomings of existing technologies, the purpose of this invention is to provide an adaptive hearing threshold auditory event-related potential (ERP) system. This system is designed to automatically measure hearing thresholds and calibrate ERP stimulation parameters without requiring subjective cooperation from the subject. It solves problems in existing ERP systems such as subjective stimulation intensity settings, neglect of individual differences, poor data quality, and difficulty in applying it to special populations. Furthermore, the hearing threshold itself can also serve as a test result for the patient.

[0012] The above-mentioned objective of this invention is achieved through the following technical solutions:

[0013] An auditory event-related potential system that adapts to hearing thresholds includes:

[0014] The acoustic stimulation module is used to generate adjustable sound pressure stimulation signals with a carrier frequency of 500-4000Hz and a modulation frequency of 35-110Hz.

[0015] The EEG acquisition module acquires the subject's EEG signals in real time;

[0016] The neural response detection module performs spectral analysis on the electroencephalogram (EEG) signal and calculates the signal-to-noise ratio (SNR) at the modulation frequency. When the SNR is greater than a set threshold, it is determined that a neural response exists.

[0017] The adaptive threshold adjustment module iteratively adjusts the sound pressure level based on the neural response results, and determines the sound pressure level with the lowest elicited response as the hearing threshold.

[0018] The ERP parameter calibration module automatically sets the ERP stimulus sound pressure level based on the hearing threshold.

[0019] As a further technical solution of the present invention: the stimulation signal output by the acoustic stimulation module adopts one of the following modulation methods:

[0020] Amplitude Modulation (AM);

[0021] FM radio;

[0022] AM+FM composite modulation;

[0023] The modulation depth ranges from 80% to 100%, forming a steady-state auditory stimulus signal.

[0024] As a further technical solution of the present invention: the spectral analysis of the neural response detection module includes the following steps:

[0025] Bandpass filtering of EEG signals was performed around the modulation frequency ±5Hz;

[0026] Perform a Fast Fourier Transform (FFT);

[0027] Calculate the SNR value at the target modulation frequency, and set the threshold to 3dB.

[0028] As a further technical solution of the present invention: the working logic of the adaptive threshold adjustment module is as follows:

[0029] The initial sound pressure level was set to 60 dB SPL;

[0030] If a neural response is detected, the sound pressure level is reduced by 5 dB; if no neural response is detected, the sound pressure level is increased by 5 dB.

[0031] The hearing threshold was determined through 3-6 rounds of iteration.

[0032] As a further technical solution of the present invention: the ERP parameter calibration module sets parameters according to the formula: target sound pressure level = hearing threshold + compensation value, wherein the compensation value can be preset, such as 30dB SPL or 130% x hearing threshold.

[0033] An automatic hearing threshold calibration method based on the above system includes the following steps:

[0034] Modulated pure tone stimuli were output to the subjects with an initial sound pressure level of 60 dB SPL.

[0035] Real-time acquisition of EEG signals and FFT spectrum analysis;

[0036] Calculate the SNR value at the modulation frequency. If the SNR > 3dB, then a neural response is determined to be present.

[0037] The sound pressure level is dynamically adjusted based on the response results, and the hearing threshold is determined through multiple iterations.

[0038] As a further technical solution of the present invention: the dynamic adjustment of sound pressure level includes:

[0039] The sound pressure level decreases by 5 dB when a response is present.

[0040] The sound pressure level increases by 5 dB when there is no response.

[0041] Repeat until two consecutive responses are opposite, and take the sound pressure level of the last response as the threshold.

[0042] As a further technical solution of the present invention, it further includes:

[0043] The hearing threshold and the compensation value are added together to generate the ERP stimulus target sound pressure level;

[0044] The compensation value can be preset, such as 30dB SPL or 130% x hearing threshold;

[0045] Automatically synchronized to the stimulus control interface of the ERP system.

[0046] As a further technical solution of the present invention, the method is suitable for the following groups of people:

[0047] Infants and young children who cannot cooperate with subjective hearing observation, patients with impaired consciousness, or patients with mental illness;

[0048] Elderly people with latent hearing loss.

[0049] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method and outputs a clinical report including hearing thresholds and ERP calibration parameters.

[0050] In summary, the present invention has at least one of the following beneficial technical effects:

[0051] This invention discloses an adaptive hearing threshold auditory event-related potential (ERP) system, an automatic hearing threshold calibration method for the system, and a computer-readable storage medium. It automatically determines an individual's hearing threshold through dynamic sound pressure stimulation, real-time EEG spectral analysis, and an adaptive iterative algorithm, and calibrates the ERP stimulation parameters accordingly. This solves the problems of subjective stimulation intensity, poor applicability to special populations, and low signal-to-noise ratio in existing technologies, significantly improving the reliability and efficiency of ERP detection. It also outputs standardized hearing reports, expanding its clinical value.

[0052] Compared with the prior art, the present invention also has the following characteristics:

[0053] Improving ERP data quality: Personalized automatic calibration ensures that each subject receives stimulation volume suitable for their own auditory sensitivity, significantly improving the amplitude and signal-to-noise ratio of the ERP signal;

[0054] Objective and accurate: The hearing threshold is automatically determined using objective neurophysiological indicators, avoiding errors caused by subjective judgment.

[0055] Fast and efficient: The entire threshold automatic calibration process is fast (can be completed within minutes), highly automated, and greatly reduces the time cost of manual calibration;

[0056] Wide range of applications: especially suitable for people who have difficulty cooperating with subjective observation and hearing (such as infants, patients with impaired consciousness, and patients with Alzheimer's disease);

[0057] Improve patient comfort: Avoid discomfort or ineffective stimulation caused by excessively high or low sound pressure levels;

[0058] It provides objective and accurate hearing function evaluation results, and the hearing threshold index can be directly used for clinical hearing screening, hearing function monitoring, and rehabilitation effect evaluation;

[0059] It effectively expands the clinical application value of ERP examination, realizes "one test, two results", improves clinical testing efficiency, and saves medical resources.

[0060] The hearing threshold data automatically measured by the adaptive hearing threshold auditory event-related potential system can be used for personalized calibration of ERP experiments, as well as automatically generate standard hearing threshold measurement reports. It can also be output as independent clinical examination results, which can serve as one of the important bases for clinicians to evaluate hearing function and diagnose diseases. Attached Figure Description

[0061] Figure 1 This is a block diagram of the overall structure of the system of the present invention.

[0062] Figure 2 This is a flowchart of the method of the present invention. Detailed Implementation

[0063] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0064] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0065] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0066] Example 1:

[0067] Reference Figure 1 The adaptive hearing threshold auditory event-related potential system disclosed in this invention includes:

[0068] The acoustic stimulation module is used to generate adjustable sound pressure stimulation signals with a carrier frequency of 500-4000Hz and a modulation frequency of 35-110Hz. The stimulation signal output by the acoustic stimulation module adopts one of the following modulation methods: amplitude modulation (AM) with a modulation depth of 80%-100%; frequency modulation (FM); or a composite modulation of AM and FM.

[0069] This module generates pure tones at preset carrier frequencies (e.g., 500Hz, 1000Hz, 1500Hz, 2000Hz, 4000Hz, etc.), with modulation waves ranging from 35 to 110Hz. This frequency range can be manually set, and stimulation is typically based on frequencies relevant to the potentials of subsequent auditory events. The stimulation signal is modulated using amplitude modulation (AM), frequency modulation (FM), or AM+FM (composite modulation), with a modulation depth (adjustable from 80% to 100%) to form a steady-state auditory stimulation signal, which is then output to the headphones. Different stimulation signals can be output to each earphone. The sound pressure level (SPL) can be adjusted in steps by the system, typically ranging from 30-90 dB SPL, with adjustable steps of 1-5 dB. The stimulation headphones must be calibrated according to IEC standards to ensure accurate SPL levels.

[0070] The EEG acquisition module acquires the subject's electroencephalogram (EEG) signals in real time. This module is used to acquire the subject's EEG signals during auditory stimulation. The EEG acquisition system supports a sampling rate of ≥1000Hz and has basic functions such as filtering, anti-aliasing, and reference electrode settings. The EEG channels include not only channels for ASSR analysis but also electrode channels for event-related potentials (ERPs).

[0071] The neural response detection module performs spectral analysis on the EEG signal and calculates the signal-to-noise ratio (SNR) at the modulation frequency. When the SNR is greater than a set threshold, a neural response is determined to be present. The spectral analysis of the neural response detection module includes the following steps: bandpass filtering the EEG signal around the modulation frequency ±5Hz; performing a Fast Fourier Transform (FFT); calculating the SNR value at the target modulation frequency, with the determination threshold set to 3dB.

[0072] This module uses spectral analysis technology to detect whether the subject has produced a stable neural response to a specific modulation frequency. The principle is as follows: after the auditory system perceives a modulated stimulus, the brainstem or cortex will synchronously discharge at the modulation frequency. This synchronous discharge is reflected in the EEG spectrum as a power enhancement at the modulation frequency. The system performs a Fast Fourier Transform (FFT) on the EEG signal to determine whether the energy peak at the modulation frequency is significantly higher than the adjacent background noise. The signal-to-noise ratio (SNR) is calculated at the modulation frequency point. If the SNR value is greater than a set threshold, it is determined that there is a "neural response".

[0073] Operating mode: The patient receives stimulation parameters and acquisition instructions; EEG data for the corresponding time period is extracted; the EEG data is preprocessed, including but not limited to bandpass filtering (e.g., modulation frequency 40Hz, bandpass range 35Hz-45Hz), removal of noise such as blinking and electromyography, and multi-segment superposition averaging to improve the signal-to-noise ratio; frequency domain analysis (FFT) is performed on the extracted EEG segments to observe whether there is a significant power peak at the target frequency point (e.g., 40Hz); the signal-to-noise ratio (SNR) is calculated; the presence of a neural response is determined, and if the SNR > threshold (e.g., 3dB), it is determined that "a response exists"; the response judgment result is output and fed back to the adaptive threshold adjustment module.

[0074] The adaptive threshold adjustment module iteratively adjusts the sound pressure level based on the neural response results to determine the sound pressure level at which the lowest eliminated response is taken as the hearing threshold. The working logic of the adaptive threshold adjustment module is as follows: the initial sound pressure level is set to 60 dB SPL; if a neural response is detected, the sound pressure level is reduced by 5 dB, and if no neural response is detected, it is increased by 5 dB; the hearing threshold is determined after 3-6 rounds of iteration.

[0075] Specifically, this module adaptively adjusts the sound pressure level based on the previous test results. The adjustment logic is as follows:

[0076] The stimulus is applied initially at a moderate intensity (e.g., 60 dB SPL). If an ASSR response is detected, the sound pressure is reduced (e.g., by 5 dB SPL each time). If no ASSR response is detected, the sound pressure is increased. This process is repeated 3-6 times at each frequency point. The final sound pressure level is stabilized at the "lowest sound pressure level that elicits a neural response," which is then used as the hearing threshold. This process can be automated without human intervention, and the measurement typically takes 1-2 minutes per ear.

[0077] The ERP parameter calibration module automatically sets the ERP stimulus sound pressure level based on the hearing threshold. The module sets the parameter according to the formula: Target Sound Pressure Level = Hearing Threshold + Compensation Value, where the compensation value is a preset 30 dB SPL. After obtaining the hearing threshold (e.g., 35 dB SPL for the right ear at 1000 Hz), the module automatically sets the target sound pressure level for the ERP stimulus according to preset rules (e.g., "threshold + 30 dB SPL") and automatically synchronizes this parameter to the ERP stimulus control interface. The test results are synchronized to the event-related potential (ERP) check report.

[0078] Example 2:

[0079] Reference Figure 2 An automatic hearing threshold calibration method based on the above system includes the following steps:

[0080] Modulated pure tone stimuli were output to the subjects with an initial sound pressure level of 60 dB SPL.

[0081] Real-time acquisition of EEG signals and FFT spectrum analysis;

[0082] Calculate the SNR value at the modulation frequency. If the SNR > 3dB, then a neural response is determined to be present.

[0083] The sound pressure level is dynamically adjusted based on the response results, and the hearing threshold is determined through multiple iterations.

[0084] The dynamic adjustment of sound pressure level includes: reducing the sound pressure level by 5dB when a response exists; increasing the sound pressure level by 5dB when no response exists; repeating until two consecutive response states are opposite, and taking the sound pressure level of the last response as the threshold.

[0085] This method further includes: adding the hearing threshold and the compensation value to generate the ERP stimulus target sound pressure level; and automatically synchronizing it to the ERP system stimulus control interface.

[0086] In this embodiment, the method is applicable to the following groups: infants and young children who cannot cooperate with subjective hearing observation, patients with impaired consciousness or mental illness; and elderly people with implicit hearing loss.

[0087] Example 3:

[0088] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method and outputs a clinical report containing hearing thresholds and ERP calibration parameters.

[0089] Experimental Example 1:

[0090] After the subjects put on the headphones, the automatic calibration process was initiated;

[0091] The stimulation generation module provides a 1000Hz carrier wave and a 40Hz modulation wave stimulation through the headphones, with an initial sound pressure level of 60dB SPL.

[0092] The EEG acquisition module acquires EEG signals in real time and performs spectral analysis on the acquired data;

[0093] If the spectral analysis shows a significant peak at the 40Hz frequency point (SNR>3dB), then the sound pressure level is reduced by 5dB and the SPL is tested again.

[0094] If there is no peak value, increase the sound pressure level by 5 dB SPL and test again;

[0095] The hearing threshold was determined through repeated testing.

[0096] Based on the determined threshold, the ERP parameter automatic calibration module automatically sets the auditory stimulation volume of the ERP system to the threshold plus 30 dB SPL and automatically updates it to the ERP system stimulation parameter setting interface for use in subsequent ERP experiments.

[0097] Experimental Example 2:

[0098] The operator places the earpiece in the subject's ear and starts the system;

[0099] The system automatically plays a modulated tone stimulus (e.g., a 1000Hz pure tone modulated at 40Hz);

[0100] EEG signal acquisition and synchronous startup; the system reads EEG data in real time.

[0101] Perform FFT analysis to determine if there is a significant peak at the 40Hz frequency point;

[0102] If present, it indicates that the sound pressure level can be sensed. Reduce the sound pressure level by 5 dB SPL and try again.

[0103] If not present → this indicates the stimulus is too weak → increase the sound pressure level by 5 dB SPL and try again;

[0104] After multiple adjustments, a minimum sound pressure level that is "just perceptible" was obtained stably;

[0105] This value is used as a threshold, and 30dB (set by the user) is automatically added to form the ERP stimulation sound pressure.

[0106] The system records and displays the audiogram, completing the calibration.

[0107] The implementation principle of this invention is as follows: This invention discloses an adaptive hearing threshold auditory event-related potential (ERP) system, an automatic hearing threshold calibration method for the system, and a computer-readable storage medium. It automatically determines an individual's hearing threshold through dynamic sound pressure stimulation, real-time EEG spectral analysis, and an adaptive iterative algorithm, and calibrates the ERP stimulation parameters accordingly. This solves the problems of subjective stimulation intensity, poor applicability to special populations, and low signal-to-noise ratio in existing technologies, significantly improving the reliability and efficiency of ERP detection. Simultaneously, it outputs standardized hearing reports, expanding its clinical value.

[0108] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An auditory event-related potential system that adapts to hearing thresholds, characterized in that, include: The acoustic stimulation module is used to generate adjustable sound pressure stimulation signals with a carrier frequency of 500-4000Hz and a modulation frequency of 35-110Hz. The EEG acquisition module acquires the subject's EEG signals in real time; The neural response detection module performs spectral analysis on the electroencephalogram (EEG) signal and calculates the signal-to-noise ratio (SNR) at the modulation frequency. When the SNR is greater than a set threshold, it is determined that a neural response exists. The adaptive threshold adjustment module iteratively adjusts the sound pressure level based on the neural response results, and determines the sound pressure level with the lowest elicited response as the hearing threshold. The ERP parameter calibration module automatically sets the ERP stimulus sound pressure level based on the hearing threshold.

2. The auditory event-related potential system for adaptive hearing thresholds according to claim 1, characterized in that, The stimulation signal output by the acoustic stimulation module adopts one of the following modulation methods: Amplitude Modulation (AM); FM radio; AM+FM composite modulation; The modulation depth ranges from 80% to 100%, forming a steady-state auditory stimulus signal.

3. The auditory event-related potential system for adaptive hearing thresholds according to claim 1, characterized in that, The spectral analysis of the neural response detection module includes the following steps: Bandpass filtering of EEG signals was performed around the modulation frequency ±5Hz; Perform a Fast Fourier Transform (FFT); Calculate the SNR value at the target modulation frequency, and set the threshold to 3dB.

4. The auditory event-related potential system for adaptive hearing thresholds according to claim 1, characterized in that, The working logic of the adaptive threshold adjustment module is as follows: The initial sound pressure level was set to 60 dB SPL; If a neural response is detected, the sound pressure level is reduced by 5 dB; if no neural response is detected, the sound pressure level is increased by 5 dB. The hearing threshold was determined through 3-6 rounds of iteration.

5. The auditory event-related potential system for adaptive hearing thresholds according to claim 1, characterized in that, The ERP parameter calibration module sets parameters according to the formula: Target sound pressure level = hearing threshold + compensation value. The compensation value can be preset, such as 30dB SPL or 130% x hearing threshold.

6. A method for automatic hearing threshold calibration based on any one of the systems of claims 1-5, characterized in that, The following steps are involved: Modulated pure tone stimuli were output to the subjects with an initial sound pressure level of 60 dB SPL. Real-time acquisition of EEG signals and FFT spectrum analysis; Calculate the SNR value at the modulation frequency. If the SNR > 3dB, then a neural response is determined to be present. The sound pressure level is dynamically adjusted based on the response results, and the hearing threshold is determined through multiple iterations.

7. The automatic hearing threshold calibration method according to claim 1, characterized in that, The dynamic adjustment of sound pressure level includes: The sound pressure level decreases by 5 dB when a response is present. The sound pressure level increases by 5 dB when there is no response. Repeat until two consecutive responses are opposite, and take the sound pressure level of the last response as the threshold.

8. The automatic hearing threshold calibration method according to claim 1, characterized in that, Further includes: The hearing threshold and the compensation value are added together to generate the ERP stimulus target sound pressure level; The compensation value can be preset, such as 30dB SPL or 130% x hearing threshold; Automatically synchronized to the stimulus control interface of the ERP system.

9. The automatic hearing threshold calibration method according to claim 1, characterized in that, The method is suitable for the following groups of people: Infants and young children who cannot cooperate with subjective hearing observation, patients with impaired consciousness, or patients with mental illness; Elderly people with latent hearing loss.

10. A computer-readable storage medium storing a computer program, characterized in that, When the program is executed by the processor, it implements the steps of any one of claims 6-9 and outputs a clinical report containing hearing thresholds and ERP calibration parameters.

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