CN-122027974-A - Room acoustic calibration method based on intermediate frequency reverberation time and related equipment

CN122027974ACN 122027974 ACN122027974 ACN 122027974ACN-122027974-A

Abstract

The invention relates to the technical field of audio acoustic calibration, and discloses a room acoustic calibration method and related equipment based on intermediate frequency reverberation time, which are used for improving the accuracy of an acoustic calibration result. The room acoustic calibration method based on the intermediate frequency reverberation time comprises the steps of obtaining room impulse response of a target room and calculating the intermediate frequency reverberation time, determining a recommended window length of a frequency related window by inquiring a predefined mapping relation according to the intermediate frequency reverberation time, establishing the mapping relation based on acoustic association between the room reverberation time and an analysis window length, determining an actual window length actually applied based on the recommended window length in combination with a user setting mode, performing time domain windowing and frequency related transfer function estimation processing on the room impulse response according to the actual window length to obtain window function weighted transfer function estimation, generating a filter calibration coefficient based on the transfer function estimation, and performing audio calibration by applying the filter calibration coefficient.

Inventors

LI JIAXIN
LIAO DONGSHENG
ZHAO LIFENG

Assignees

南京乐韵瑞信息技术有限公司

Dates

Publication Date: 20260512
Application Date: 20260416

Claims (15)

1. The room acoustic calibration method based on the intermediate frequency reverberation time is characterized by comprising the following steps of: Acquiring a room impulse response of a target room and calculating intermediate frequency reverberation time; determining a recommended window length of a frequency-dependent window by querying a predefined mapping relationship according to the intermediate frequency reverberation time, the mapping relationship being established based on acoustic correlation between the room reverberation time and the analysis window length; determining the actual window length of the actual application based on the recommended window length and in combination with a user setting mode; Performing time domain windowing and frequency-dependent transfer function estimation processing on the room impulse response according to the actual window length to obtain window function weighted transfer function estimation; Filter calibration coefficients are generated based on the transfer function estimate and applied for audio calibration.
2. The room acoustic calibration method based on the mid-frequency reverberation time according to claim 1, wherein the acquiring the room impulse response of the target room and calculating the mid-frequency reverberation time comprises: playing a test signal in a target room through audio playing equipment, and collecting a response signal of the test signal after the test signal propagates through the room through a microphone; calculating a room impulse response based on the test signal and the response signal; band-pass filtering the room impulse response, and extracting impulse response components of an intermediate frequency band; And calculating an energy attenuation curve by a Schrode inverse integration method based on the impulse response component of the intermediate frequency band, and performing linear fitting on the energy attenuation curve to estimate intermediate frequency reverberation time.
3. The room acoustic calibration method based on mid-frequency reverberation time according to claim 1, wherein the determining a recommended window length of a frequency dependent window by querying a predefined mapping relation according to the mid-frequency reverberation time comprises: When the intermediate frequency reverberation time is not smaller than a preset first time threshold value, determining a preset minimum window length as a recommended window length; when the intermediate frequency reverberation time is not greater than a preset second time threshold, determining a preset maximum window length as a recommended window length, wherein the first time threshold is greater than the second time threshold; And determining a recommended window length based on interpolation calculation when the intermediate frequency reverberation time is greater than the second time threshold and less than the first time threshold.
4. A room acoustic calibration method based on mid-frequency reverberation time according to claim 3 wherein the determining a recommended window length based on interpolation calculations comprises: Calculating the offset of the intermediate frequency reverberation time relative to the second time threshold value, and taking the difference value between the first time threshold value and the second time threshold value as the interpolation interval length; calculating a normalization ratio according to the ratio of the offset to the length of the interpolation interval; According to the maximum window length, the minimum window length and the normalization proportion, adopting reverse mapping calculation to obtain a floating point value of the recommended window length, wherein the larger the normalization proportion is, the smaller the calculated floating point value is; And rounding the floating point value to obtain the recommended window length.
5. The room acoustic calibration method based on mid-frequency reverberation time of claim 1, wherein the determining an actual window length for actual application based on the recommended window length in combination with a user setting mode comprises: If the current mode is the user automatic mode, the recommended window length is used as the actual window length; If the current manual mode is the user manual mode, acquiring the designated window length designated by the user as the actual window length; And in the manual mode of the user, triggering a defensive interaction mechanism if the intermediate frequency reverberation time is detected to exceed a preset risk threshold and the specified window length exceeds a preset safety upper limit.
6. The room acoustic calibration method based on mid-frequency reverberation time of claim 5 wherein the triggering defensive interaction mechanism comprises: determining a risk level according to the intermediate frequency reverberation time and the specified window length; based on the risk level, performing a corresponding interactive operation including at least one of issuing a risk prompt, limiting a window length adjustment range, or enforcing an application recommendation window length.
7. The room acoustic calibration method based on mid-frequency reverberation time of claim 6 further comprising, after determining an actual window length for actual application based on the recommended window length in combination with a user-set mode: recording state information of the recommended window length, the actual window length, user mode selection and whether a defense mechanism is triggered or not; writing the state information into the calibration result data.
8. The room acoustic calibration method based on intermediate frequency reverberation time of claim 1 wherein said performing a time-domain windowing and frequency-dependent transfer function estimation process on said room impulse response based on said actual window length to obtain a window function weighted transfer function estimate comprises: Determining the lengths of target effective time windows corresponding to different frequency bands according to the actual window lengths; performing time domain windowing on the room impulse response based on the target effective time window length to obtain a windowed impulse response; And performing frequency domain conversion on the windowed impulse response to obtain a window function weighted transfer function estimation.
9. The room acoustic calibration method based on intermediate frequency reverberation time according to claim 8, wherein the determining effective time window lengths corresponding to different frequency bands according to the actual window length includes: Dividing a target frequency band into a plurality of sub-frequency bands according to a preset frequency segmentation rule; For each sub-band, converting the actual window length into an effective time window length in the time domain according to the central frequency or frequency band characteristic; and carrying out fine adjustment on the frequency correlation of the effective time window length according to the difference of the sensitivity of the direct sound and the reflected sound of different frequency bands to obtain the target effective time window length.
10. The room acoustic calibration method based on intermediate frequency reverberation time of claim 8 wherein the time-domain windowing of the room impulse response based on the target effective time window length results in a windowed impulse response comprising: Generating a time domain window function sequence according to the corresponding target effective time window length of each frequency band; performing multiplication operation on the time domain window function sequence and the room impulse response in the time domain; And cutting off the multiplied signals, and reserving data in the length of the target effective time window to form a windowed impulse response.
11. The room acoustic calibration method based on intermediate frequency reverberation time of claim 8 wherein the frequency domain converting the windowed impulse response to a window function weighted transfer function estimate comprises: Performing a fast fourier transform on the windowed impulse response, converting it to the frequency domain; Smoothing or band averaging is carried out on the signals after the frequency domain conversion; and taking the processed frequency domain signal as a transfer function estimation weighted by a window function.
12. The room acoustic calibration method based on intermediate frequency reverberation time of claim 1 wherein the generating filter calibration coefficients based on the transfer function estimate and applying the filter calibration coefficients for audio calibration comprises: comparing the transfer function estimation with a preset target frequency response to obtain a frequency response difference to be compensated; Calculating a filter calibration coefficient based on the frequency response difference; and applying the filter calibration coefficient to a filter in an audio processing link to calibrate the played audio signal.
13. Room acoustic calibration apparatus based on mid-frequency reverberation time, characterized in that it comprises: The acquisition module is used for acquiring the room impulse response of the target room and calculating the intermediate frequency reverberation time; the first determining module is used for determining the recommended window length of the frequency correlation window by inquiring a predefined mapping relation according to the intermediate frequency reverberation time, and the mapping relation is established based on acoustic association between the room reverberation time and the analysis window length; The second determining module is used for determining the actual window length of the actual application based on the recommended window length and in combination with a user setting mode; the processing module is used for carrying out time domain windowing and frequency-related transfer function estimation processing on the room impulse response according to the actual window length to obtain window function weighted transfer function estimation; and the calibration module is used for generating a filter calibration coefficient based on the transfer function estimation and applying the filter calibration coefficient to perform audio calibration.
14. An electronic device comprising a memory and at least one processor, the memory having instructions stored therein; the at least one processor invokes the instructions in the memory to cause the electronic device to perform the room acoustic calibration method based on mid-frequency reverberation time according to any one of claims 1 to 12.
15. A computer readable storage medium having instructions stored thereon, which when executed by a processor, implement the room acoustic calibration method based on intermediate frequency reverberation time according to any one of claims 1 to 12.

Description

Room acoustic calibration method based on intermediate frequency reverberation time and related equipment Technical Field The invention relates to the technical field of audio acoustic calibration, in particular to a room acoustic calibration method based on intermediate frequency reverberation time and related equipment. Background Currently prevailing room acoustic calibration systems typically analyze the room impulse response with a fixed time window to estimate the frequency response of the room and generate equalization correction parameters. However, the acoustic properties of the room, especially the reverberation time, vary significantly due to space size, decorative materials and layout differences, and a fixed analysis window length is difficult to generalize, i.e. in an "active" room with long reverberation time, too long an analysis window can incorporate a lot of late reverberation energy, resulting in distortion of the transfer function estimation, leading to excessive equalization, dry sound or loss of detail, and in a "silent" room with short reverberation time, too short an analysis window can not adequately capture the beneficial spatial information in the early reflections, resulting in a thin sound, lack of naturalness after calibration. In addition, the existing method mostly ignores the difference of sound wave attenuation characteristics of different frequency bands (such as long low-frequency reverberation and fast high-frequency attenuation), adopts unified window processing to process full-frequency band signals, and further limits calibration accuracy and hearing adaptability. Disclosure of Invention The invention provides a room acoustic calibration method based on intermediate frequency reverberation time and related equipment, which are used for solving the problem of lower accuracy of a calibration result caused by room acoustic calibration by adopting a fixed analysis window length in the prior art. The invention provides a room acoustic calibration method based on intermediate frequency reverberation time, which comprises the steps of obtaining room impulse response of a target room and calculating the intermediate frequency reverberation time, determining a recommended window length of a frequency-dependent window according to the intermediate frequency reverberation time by inquiring a predefined mapping relation, establishing the mapping relation based on acoustic association between the room reverberation time and an analysis window length, determining an actual window length actually applied according to a user setting mode based on the recommended window length, performing time domain windowing and frequency-dependent transfer function estimation processing on the room impulse response according to the actual window length to obtain a transfer function estimation of window function weighting, generating a filter calibration coefficient based on the transfer function estimation, and performing audio calibration by applying the filter calibration coefficient. In a possible implementation manner, the method for acquiring the room impulse response of the target room and calculating the intermediate frequency reverberation time comprises the steps of playing a test signal in the target room through an audio playing device, collecting a response signal of the test signal after the test signal propagates through the room through a microphone, calculating the room impulse response based on the test signal and the response signal, carrying out band-pass filtering on the room impulse response, extracting impulse response components of an intermediate frequency band, calculating an energy attenuation curve based on the impulse response components of the intermediate frequency band through a Schrode inverse integration method, and carrying out linear fitting on the energy attenuation curve to estimate the intermediate frequency reverberation time. In a possible implementation manner, the determining the recommended window length of the frequency-dependent window according to the intermediate frequency reverberation time by querying a predefined mapping relation includes: When the intermediate frequency reverberation time is not smaller than a preset first time threshold value, determining a preset minimum window length as a recommended window length; when the intermediate frequency reverberation time is not greater than a preset second time threshold, determining a preset maximum window length as a recommended window length, wherein the first time threshold is greater than the second time threshold; And determining a recommended window length based on interpolation calculation when the intermediate frequency reverberation time is greater than the second time threshold and less than the first time threshold. In a possible implementation manner, the determining the recommended window length based on interpolation calculation includes calculating an offset of the intermediate freque