For correction system of English pronunciation errors, the level of correction performance and the reliability, practicability, and adaptability of information feedback are the main basis for evaluating its excellent comprehensive performance. In view of the disadvantages of traditional English pronunciation correction systems, such as failure to timely feedback and correct learners’ pronunciation errors, slow improvement of learners’ English proficiency, and even misleading learners, it is imperative to design a scientific and efficient automatic correction system for English pronunciation errors. High-sensitivity acoustic wave sensors can identify English pronunciation error signal and convert the dimension of collected pronunciation signal according to channel configuration information; acoustic wave sensors can then assist the automatic correction system of English pronunciation errors to filter out interference components in output signal, analyze real-time spectrum, and evaluate the sensitivity of the acoustic wave sensor. Therefore, on the basis of summarizing and analyzing previous research works, this paper expounds the current research status and significance of the design of automatic correction system for English pronunciation errors, elaborates the development background, current status and future challenges of high-sensitivity acoustic wave sensor technology, introduces the methods and principles of time-domain signal amplitude measurement and pronunciation signal preprocessing, carries out the optimization design of pronunciation recognition sensors, performs the improvement design of pronunciation recognition processors, proposes the hardware design of automatic correction system for English pronunciation errors based on the assistance of high-sensitivity acoustic wave sensors, analyzes the acquisition program design for English pronunciation errors, implements the parameter extraction of English pronunciation error signal, discusses the software design of automatic correction system for English pronunciation errors based on the assistance of high-sensitivity sound wave sensor, and finally, conducts system test and its result analysis. The study results show that the automatic correction system of English pronunciation errors assisted by the high-sensitivity acoustic wave sensors can realize the automatic correction of the amplitude linearity, sensitivity, repeatability error, and return error of English pronunciation errors, which has the robust functions of automatic real-time data collection, processing, saving, query, and retesting. The system can also minimize external interference and improve the accuracy of acoustic wave sensors’ sensitivity calibration, and it provides functions such as reading and saving English pronunciation error signals and visual operation, which effectively improves the ease of use and completeness of the correction system. The study results in this paper provide a reference for the further researches on the automatic correction system design for English pronunciation errors assisted by high-sensitivity acoustic wave sensors.
1. Introduction
In the process of learning English, there is a phenomenon that some learners’ spoken language is poor, and as a critical and difficult part of English learning, spoken language has received increasing attention. Therefore, it is imperative to design a scientific and efficient automatic correction system for English pronunciation errors. The traditional English pronunciation correction system cannot provide timely feedback and correction for learners’ pronunciation errors and has disadvantages such as misleading learners and slow improvement of learners’ English proficiency [1]. For the automatic correction system for English pronunciation errors, the level of correction performance and the reliability and practicability of information feedback are the main basis for evaluating its comprehensive performance. The quality of the correction algorithm determines the correction performance, and a reasonable error detection method guarantees [2]. After decomposing and optimizing each subtarget in the multitarget, the high-sensitivity acoustic wave sensor will trade off and coordinate them to make each subtarget. This is because the input information and output information required in the automatic correction of English pronunciation errors are related to the open failure system. The automatic correction system for English pronunciation errors can be divided into two parts: system training and pronunciation correction [3]. The training process of the system is similar to the training in the automatic pronunciation recognition system. The known standard pronunciation information features are extracted and recorded as the standard for pronunciation correction. Pronunciation correction is to correct the pronunciation accuracy of the pronunciation to be tested. The basic process is to extract the features of the pronunciation to be tested, compare its standard pronunciation features, and calculate the score based on the similarity [4].
The high-sensitivity acoustic wave sensor can follow the artificial neural network model, use target tracking to design an automatic correction system, and form an abstract logic layer by combining the characteristics of English pronunciation errors. The similarity between the single target tracking algorithm and the traditional neural network is that they both use a hierarchical structure to construct the logical layer, but the difference is that the three-layer construction mode is the most suitable for automatic correction system [5]. Relying on the optimized design of the pronunciation recognition sensor and the improved design of the pronunciation recognition processor, the software design of the system is completed based on the design of the English pronunciation acquisition program and the extraction of English pronunciation error signal parameters. In this process, although the amount of data is large and the calculations are more complicated, the calculation process of each sentence is the same [6]. It is necessary to use analog-digital signal conversion to improve the data sampling efficiency, and the sampling efficiency is not less than a certain value and the single-target tracking algorithm is used to continuously perform repeated iterative calculations [7]. In pronunciation recognition, a multifrequency oscillator is designed to automatically calibrate the pronunciation accuracy, while the calibration of the circuit conversion is the key to realize the conversion of the English printing information mode. By collecting and controlling the original pronunciation information of the circuit, the accuracy of system’s automatic correction data can be improved [8].
Based on the summary and analysis of previous research results, this paper expounds the current research status and significance of the design of automatic correction system for English pronunciation errors, elaborates the development background, current status, and future challenges of high-sensitivity acoustic wave sensor technology, introduces the methods and principles of time-domain signal amplitude measurement and pronunciation signal preprocessing, carries out the optimization design of pronunciation recognition sensors, performs the improvement design of pronunciation recognition processors, proposes the hardware design of automatic correction system for English pronunciation errors based on the assistance of high-sensitivity acoustic wave sensors, analyzes the acquisition program design for English pronunciation errors, implements the parameter extraction of English pronunciation error signal, discusses the software design of automatic correction system for English pronunciation errors based on the assistance of high-sensitivity sound wave sensor, and finally, conducts system test and its result analysis. The detailed chapters are arranged as follows: Section 2 introduces the methods and principles of time-domain signal amplitude measurement and pronunciation signal preprocessing; Section 3 proposes the hardware design of automatic correction system for English pronunciation errors based on the assistance of high-sensitivity acoustic wave sensors; Section 4 discusses the software design of automatic correction system for English pronunciation errors based on the assistance of high-sensitivity sound wave sensor; Section 5 conducts system test and its result analysis; Section 6 is the conclusion.
2. Methods and Principles
2.1. Amplitude Measurement of Time Domain Signal
From the perspective of the characteristics of the automatic correction system for English pronunciation errors; the assistance of the high-sensitivity acoustic wave sensor is actually a system function to obtain the required frequency response characteristics, and the same is true for digital filtering. For a linear time-invariant causal simulation system, the relationship between its input and output is where is the input of the system; is the output response of the system; is the continuous time component; is the transfer function of the system; is the number of convolution operators.
For the input English phoneme of the system, given the observation vector of each frame of the th segment of pronunciation related to it, calculate its frame-based posterior probability as where is the probability distribution of the observation vector for a given phoneme ; is the prior probability of phoneme ; is the summation function of all text independent phonemes.
The design of the high-sensitivity acoustic wave sensor-assisted automatic correction system for English pronunciation errors has passed the first-level calibration to measure the sensitivity of the standard acoustic wave sensor, so the final calculation formula for the sensitivity of the sensor under test is where is the sensitivity of the standard acoustic wave sensor; is the sensitivity of the acoustic wave sensor to be measured; is the amplitude of the acoustic wave sensor to be measured; is the amplitude of the reference acoustic wave sensor.
The development of the correction system first recognizes the English pronunciation error signal and then performs dimensional conversion on the collected English pronunciation error signal according to the channel configuration information. Then, the high-sensitivity acoustic wave sensor is embedded in the correction system. The measurement process first filters the pronunciation signal to filter out the interference components in the output signal of the acoustic wave sensor; the system performs real-time spectrum analysis on the filtered English pronunciation error signal and evaluates the sensitivity of acoustic wave sensor [9]. Therefore, the system can minimize external interference and improve the accuracy of sensor sensitivity calibration when there is interference in the on-site environment. In addition, the software provides auxiliary functions such as reading and saving the pronunciation error signal and the operation of the visualization area to improve the ease of use and completeness of the system. The system uses a control signal source and an oscilloscope to complete the task of sending and collecting English pronunciation errors signals. Due to the limitation of the number of measurements, a loop control structure is added to measure the sensitivity of the sensor under test to achieve a certain number of cycles, and the oscilloscope collects signals are added to the program to ensure the integrity of signal reception and finally realize the task of channel triggering and channel reception.
2.2. Pronunciation Signal Preprocessing
After the high-sensitivity acoustic wave sensor calculates the ratio of signal input to output, the system function can be obtained by pulling and transforming the comparison value. The acoustic wave sensor is designed by the impulse response method, and the general form of the function for pronunciation error correction is where is the acoustic wave sensor coefficient of the th state at time ; is the cumulative output probability of the th state at time ; is the previous state number of the th state at time ; is the optimal state sequence at time status.
The logarithm of the posterior probability of the phoneme in the th segment of pronunciation for each meal of the English pronunciation error signal is taken, and then, the logarithmic posterior probability score of the phoneme under the th segment of pronunciation can be obtained: where is the duration of the th time period corresponding to phone ; is the normalized function of the th time period of phone ; is the likelihood of the segment of the th time period of phone ; is the final output probability.
The sound wave sensor-assisted automatic correction system regards English pronunciation errors as a common pronunciation classification problem and uses a classification model to solve this problem. This model is based on a four-layer feed-forward network, which includes a pronunciation vector mapping table; the formula for inputting the input layer vector into the feed-forward network for forward calculation is as follows: where is the network weight; is the bias value; is the activation function; is the output value of the corresponding layer; is the learning rate; is the dimension of the pronunciation error; is the size of the vector table of the pronunciation error.
English pronunciation error preprocessing includes sampling of English pronunciation errors, antialiasing band-pass filtering to remove individual pronunciation differences and noise effects caused by equipment and environment. English pronunciation error is an unstable random process, so it needs to use high-sensitivity acoustic wave sensor for short-term processing and involves primitive selection and endpoint detection of pronunciation recognition [10]. Endpoint detection refers to determining the start and end of pronunciation from English pronunciation errors, which is an important part of preprocessing. The process of pronunciation recognition is a process of digitally processing English pronunciation errors. Before processing English pronunciation errors, they must be digitally processed, and this process is analog-to-digital conversion. The analog-to-digital conversion process has to go through two processes, sampling and quantization, to obtain discrete digital signals in time and amplitude, and preemphasis is usually performed before transformation and after antialiasing filtering. After the system obtains learner’s follow-up pronunciation, it extracts its characteristics and calculates the similarity between it and the standard pronunciation in the test question bank and finally maps the similarity to a grade score that is easier for the learner to understand and accept.
3. Hardware Design of Automatic Correction System Based on High-Sensitivity Acoustic Wave Sensors
3.1. Optimization Design of Pronunciation Recognition Sensors
In order to ensure the accuracy, reliability, unity, and self-adaptability of English pronunciation errors correction and to adapt to the development trend of automatic correction, the system hardware design must carry out effective measurement supervision on the accuracy and reliability of the sound wave sensor’s measurement value transmission to standardize and perfect the calibration of the sensor. The main components include raster data conditioning module, sensor output conditioning module to be calibrated, and acquisition device and computer system. This module can, respectively, realize the correction of the amplitude linearity, sensitivity, repeatability error, and return error of English pronunciation errors, and has the functions of automatic real-time data collection, data processing, storage, query, and remeasurement. The grating ruler is converted into the corresponding electrical signal through its conditioning circuit, and the corresponding processing is carried out by the formant acquisition card and the English pronunciation signal is input into the system. The sensor to be calibrated outputs the corresponding voltage or current through its conditioning circuit, through data acquisition device, use the interface to achieve serial communication, set the data acquisition device in the reset state, establish the trigger condition, and initialize the control settings; the model can enter the working state, open the serial port, input the output signal into the computer system, and finally, respond with the collected data analysis and processing [11]. Figure 1 shows the automatic correction system design framework for English pronunciation errors assisted by high-sensitivity acoustic wave sensors.