CN110164478B - Method for digitally converting steel wire recording - Google Patents

Abstract

The invention discloses a method for digitally converting steel wire sound recording, which relates to the field of digital conversion of steel wire sound recording and comprises the following steps: step 1: pre-preparing a digital conversion environment; step 2: installation and configuration of conversion equipment; and step 3: preheating the playback equipment; and 4, step 4: installing a steel wire belt; and 5: adjusting the test tone; step 6: performing playback acquisition, namely acquiring in a single track mode; and 7: storing data; and 8: rewinding and reducing; and step 9: the digital conversion work is completed. The method for digitally converting the steel wire audio record can realize the high-efficiency and high-quality digital conversion work of the steel wire audio file by utilizing the existing steel wire recorder, greatly reduce the playing times of the steel wire audio file and protect the existing steel wire audio file to the maximum extent; and the disk space occupied by the digitally converted audio can be reduced.

Description

Method for digitally converting steel wire recording

Technical Field

The invention relates to the field of digital conversion of steel wire sound recordings, in particular to a method for digitally converting steel wire sound recordings.

Background

Edison invented gramophone in 1877, created the miracle on the human history, make the sound can be stored and reproduced; in 1898, the danish scientist bursen developed a first magnetic recorder, and in the paris exposition of 1900, the magnetic recorder invented by bursen was shown, which recorded sound on a steel wire; in 1937, the improved steel wire recorder was invented by Marfan, and has the characteristics of vivid sound and beautiful tone quality.

Steel wire recording once plays an important role in the field of audio archives in China, a plurality of audio archives still remain in a steel wire recording tape at present, and because the time is long and the steel wire is aged, most of the steel wire recording tapes are at the edge where rescue is needed urgently, digital conversion is urgently needed, audio information stored in the steel wire recording tape is truly recorded as far as possible in the digital work of the steel wire recording, and meanwhile destructive loss is not caused to the steel wire recording tape. The steel wire of the existing steel wire audio tape is seriously aged, the playing times of the steel wire audio tape are quite limited, and some steel wire audio tapes can be broken after being played for only a few times, so that the playing times of the steel wire audio tape when the steel wire audio tape is digitally converted need to be reduced as far as possible. Meanwhile, the steel wire recorder serving as playing equipment of the steel wire audio tape has been out of production for decades, and how to utilize the existing steel wire recorder to combine with the existing technical conditions to complete the digital conversion work of the steel wire audio file efficiently and with high quality is always a key problem for research of related technical personnel.

The existing audio recording mostly adopts a stereo sound channel or a left sound channel and a right sound channel, but the problem that the hard disk space occupies too much when the stereo sound channel or the left sound channel and the right sound channel are adopted is solved.

Therefore, those skilled in the art have been devoted to develop a method for digitally converting steel wire audio records, which not only can realize the high-efficiency and high-quality digital conversion of steel wire audio files by using the existing steel wire recorder, but also can reduce the disk space occupied by the digitally converted audio.

Disclosure of Invention

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to utilize the existing steel wire recorder to perform high-efficiency and high-quality digital conversion work on the steel wire audio file and reduce the disk space occupied by the digitally converted audio on the premise of reducing the playing times of the steel wire audio file as much as possible and protecting the existing steel wire audio file to the utmost extent.

In order to achieve the above object, the present invention provides a method for digitally converting a steel wire audio recording, comprising the steps of:

step 1: pre-preparing a digital conversion environment;

step 2: installation and configuration of conversion equipment; the conversion equipment comprises playback equipment, a collection card, a computer, a monitoring earphone, an audio line and a temperature control system; the playback equipment comprises an output interface, a tone knob, a function knob, an output channel knob, a volume knob, a toggle button for playing/rewinding, a toggle switch for playing/rewinding, a winding roll, a magnetic head height scale, a magnetic head notch, a winding roll bayonet, a lead clamping press plate button, a lead clamping press plate, a wire supply roll and a safety post;

and step 3: preheating the playback equipment;

and 4, step 4: installing a steel wire belt;

and 5: adjusting the test tone;

step 6: playback collection; adopting a single track mode for acquisition;

and 7: storing data;

and 8: rewinding and reducing;

and step 9: the digital conversion work is completed.

Further, the step 1 comprises the following steps:

step 1.1: the environment temperature of a digital conversion working place is controlled between 20 ℃ and 27 ℃ by adopting a cooling and heating air conditioner, and the humidity is controlled between 55 percent and 70 percent;

step 1.2: the worker wears the dustproof clothes, the dustproof shoes, the dustproof caps, the medical plastic gloves and other equipment;

step 1.3: the sound reproduction equipment is placed on a stable working platform, the working platform is a solid rigid body, the working platform comprises a damping device, and the damping device is made of plastic or rubber;

step 1.4: a noise source and a vibration source are not arranged near the working platform; the noise standard value of the noise source is more than or equal to 70dB, and the vibration intensity of the vibration source is more than 0.71 mm/s;

step 1.5: during digital sampling, the manual touch of a workbench or conversion equipment is absolutely avoided, so that signal distortion caused by vibration is prevented.

Further, the step 2 comprises the following steps:

step 2.1: the tone knob of the playback equipment is turned to be in an off state, and the power supply of the playback equipment is in the off state;

step 2.2: connecting the acquisition card with the computer, wherein the acquisition card is configured to be in a standby state, and all buttons of the acquisition card are in an initial state;

step 2.3: inspecting the notch of the magnetic head, and cleaning dust and dirt at the notch of the magnetic head; the method for cleaning the dust and dirt at the notch of the magnetic head comprises the steps of using a toothbrush soaked in tetrachloride or absolute alcohol to scrub and clean the notch of the magnetic head after a power supply is turned off;

step 2.4: respectively inserting the positive electrode of the first end of the audio cable and the grounding wire into the positive electrode end and the grounding end of the output interface, and meeting the wiring terminal standard, wherein the wiring terminal standard is that the metal parts of the joint of the audio cable are all inserted into the corresponding ports and are fixed and stable;

step 2.5: connecting the second end of the audio line to the input end of the acquisition card, and meeting the standard of a terminal;

step 2.6: connecting the monitoring earphone with the acquisition card;

step 2.7: the temperature control system is connected and used for controlling the temperature of the notch of the magnetic head and the surface temperature of the steel wire at the inlet of the magnetic head, and the surface temperature of the steel wire at the inlet of the magnetic head is kept within a first temperature control range, wherein the first temperature control range is 24-27 ℃.

Further, the step 3 comprises the following steps: switching on a power supply of the playback equipment, rotating the tone knob, starting the power supply of the playback equipment, and preheating the playback equipment, wherein the preheating time is 15-30 minutes, and the preheating completion standard is that the temperature change of the notch of the magnetic head is less than 0.4 ℃ in a time period of 5 minutes or more; and when the temperature of the notch of the magnetic head is more than or equal to 35 ℃, the temperature control system is automatically started until the temperature of the notch of the magnetic head is less than or equal to 25.5 ℃, and then the temperature control system is stopped.

Further, the step 4 comprises the following steps:

step 4.1: wearing plastic gloves, and avoiding the direct touch of both hands on the steel wire in the whole installation process;

step 4.2: the method comprises the steps of detecting a steel wire belt, judging whether rust exists or a lead is lost, and removing rust of the steel wire belt with the rust, wherein the rust removal method comprises the steps of scraping a rusted steel wire by using soft cloth or an ultra-pure steel wire group, soaking the soft cloth by using a rust remover and then wiping the rusted steel wire; the steel wire belt with the missing lead wire needs to be connected firstly; broken steel wires exist, and the broken steel wires need to be connected; the connecting method of the broken steel wires comprises the steps of buckling a flat knot at the wire head of the steel wires to be connected, and then tensioning and shearing off the redundant steel wires;

step 4.3: pressing the toggle button of the playing/rewinding, and toggling the toggle switch of the playing/rewinding to a rewinding state;

step 4.4: rotating the winding roll to enable the magnetic head to move upwards until the winding roll is level to the top end of the height scale of the magnetic head;

step 4.5: placing the steel wire disc on the wire supply disc, and pulling out a steel wire lead in a clockwise direction;

step 4.6: the steel wire must pass through the magnetic head notch, and the lead must pass through the winding roll bayonet; the lead clamping press plate is lifted by pressing the lead clamping press plate button, a lead passes through the lead clamping press plate, and the lead is clamped by loosening the lead clamping press plate button;

step 4.7: adjusting the wire supply disc to enable the steel wire to be in a straightening state;

step 4.8: and the toggle switch for playing/rewinding is toggled to the middle position.

Further, the step 5 comprises the following steps:

step 5.1: turning the tone knob, turning on the power supply of the playback equipment, and turning the knob to a proper gear;

step 5.2: the function knob is pulled to a listening gear;

step 5.3: according to the output port accessed by the audio cable in the step 2.3, rotating the output channel knob to a corresponding gear;

step 5.4: rotating the volume knob until the volume is normally audible to a worker;

step 5.5: pressing the toggle button of the playing/rewinding, toggling the toggle switch of the playing/rewinding to a playing state, and starting playing;

step 5.6: in the sound testing process, a worker needs to determine whether the audio signal normally enters the earphone and the acquisition software, and if the audio signal is abnormal, the worker needs to check;

step 5.7: the volume knob is rotated to control the volume until the peak value of the level amplitude of the collected audio signal is smaller than-3 dB, and the average value of the level amplitude RMS is between-30 dB and-10 dB; if the volume knob is adjusted to the maximum, the peak value of the level amplitude of the collected audio still cannot reach-20 dB, the gain knob on the collection card is adjusted to gain, and the gain amplitude does not exceed 15 dB;

step 5.8: the sound testing time is not more than 3 minutes, the tape rewinding is restored after the sound testing is successful, and the adjustment parameters of the sound playing equipment, the acquisition card and the sampling recording software are kept unchanged.

Further, the step 6 comprises the following steps:

step 6.1: opening audio acquisition software, and acquiring in a single track mode; the content of the steel wire recording tape to be sampled is divided into three types of songs, Chinese national opera songs and languages, and the content types of different steel wire recording tapes are respectively set with the sampling frequency, the sampling precision, the sampling tone and the sampling volume for recording and collecting;

step 6.2: pressing the toggle button of the playing/rewinding, toggling the toggle switch of the playing/rewinding to a playing state, and starting playback acquisition;

step 6.3: in the playback acquisition process, a worker monitors whether the acquired audio signal is normal by using an earphone, and if the acquired audio signal is abnormal, the reason needs to be searched for to be checked; if the fault of sound reproduction interruption such as non-steel wire breakage occurs, sampling and recording are continued until the work is finished, and then fault analysis and processing are carried out;

step 6.4: after the playback is finished, pressing the toggle button of the play/rewind to toggle the toggle switch of the play/rewind to the middle position;

step 6.5: and after leaving white for 3-5 seconds, closing the sampling and recording function of the audio software.

Further, the step 7 includes the steps of:

step 7.1: audio acquisition software is used for storing audio contents;

step 7.2: naming the digital file according to a naming rule;

step 7.3: and recording information of the acquisition process.

Further, the step 8 comprises the following steps:

step 8.1: turning the volume knob to adjust the volume of the playback equipment to the lowest;

step 8.2: pressing the toggle button of the playing/rewinding, and toggling the toggle switch of the playing/rewinding to a rewinding state;

step 8.3: waiting for the end of rewinding;

step 8.4: when the rewinding is finished, the lead can poke the safety post to enable the playback equipment to be in a power-off state;

step 8.5: pressing the lead clamping press plate button to loosen the lead clamping press plate and taking a lead out of the lead clamping press plate;

step 8.6: taking out the lead wires from the bayonet of the winding roll and the notch of the magnetic head respectively, and taking the steel wire recording tape away from the wire supply roll;

step 8.7: the lead is clockwise wound on the steel wire recording tape, and the lead head is fixed by the medical adhesive tape.

Further, the step 9 includes the steps of:

step 9.1: restoring the playing/rewinding toggle switch and the volume knob of the playback equipment;

step 9.2: restoring a functional knob on the acquisition card;

step 9.3: and rotating the tone knob to a closing gear to close the power supply of the playback equipment.

Compared with the prior art, the implementation of the invention achieves the following obvious technical effects:

1. the method for digitally converting the steel wire audio record can utilize the existing steel wire recorder to perform high-efficiency and high-quality digital conversion work on the steel wire audio file;

2. the method for digitally converting the steel wire audio record greatly reduces the playing times of the steel wire audio file and protects the existing steel wire audio file to the maximum extent;

3. the invention provides a method for digitally converting steel wire sound recording, which reduces the disk space occupied by digitally converted audio.

4. The method for digitally converting the steel wire audio record provided by the invention can effectively improve the success rate of playing the steel wire audio file by the existing steel wire audio recorder and further reduce the waste of time and disk space caused by abnormal conversion.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is a diagram of the steps of a method for digitally converting a steel wire audio recording in accordance with a preferred embodiment of the present invention;

fig. 2 is a schematic top view of a playback device according to a preferred embodiment of the invention;

fig. 3 is a rear-view enlarged schematic view of a playback apparatus in accordance with a preferred embodiment of the present invention;

fig. 4 is a schematic front view of a playback apparatus according to a preferred embodiment of the invention;

FIG. 5 is a schematic diagram of an output interface of a playback device according to a preferred embodiment of the present invention;

FIG. 6 is a frequency response plot for a sample frequency of 44.1kHz in accordance with a preferred embodiment of the present invention;

FIG. 7 is a frequency response plot for a sampling frequency of 48kHz in accordance with a preferred embodiment of the present invention.

The system comprises a 1-magnetic head, a 2-magnetic head height scale, a 3-winding reel bayonet, a 4-lead clamping pressing plate, a 5-lead clamping pressing plate button, a 6-winding reel, a 7-play/rewind toggle button, an 8-play/rewind toggle switch, a 9-wire supply reel, a 10-safety column, an 11-magnetic head notch, a 12-volume knob, a 13-function knob, a 14-output channel knob, a 15-tone knob, a 16-output interface, a 161-positive terminal and a 162-grounding terminal.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.

As shown in fig. 1, the method for digitally converting a steel wire audio record provided in this embodiment includes the following steps: step 1: pre-preparing a digital conversion environment; the method specifically comprises the following steps:

step 1.1: the environment temperature of a digital conversion working place is controlled between 20 ℃ and 27 ℃ by adopting a cooling and heating air conditioner, and the humidity is controlled between 55 percent and 70 percent;

step 1.2: the worker wears the dustproof clothes, the dustproof shoes, the dustproof caps, the medical plastic gloves and other equipment;

step 1.3: the playback equipment is placed on a stable working platform, the working platform is a solid rigid body, and the working platform comprises a damping device;

step 1.4: no noise source or vibration source is arranged near the working platform; the noise standard value of the noise source is more than or equal to 70dB, and the vibration intensity of the vibration source is more than 0.71 mm/s;

step 1.5: during digital sampling, the manual touch of a workbench or conversion equipment is absolutely avoided, so that signal distortion caused by vibration is prevented.

Step 2: installation and configuration of conversion equipment; the conversion equipment comprises playback equipment, a collection card, a computer, a monitoring earphone, an audio line and a temperature control system; the model of the playback equipment is 288-1R type, the brand is Webster-Chicago, the power requirement is 120V, 60Hz, as shown in fig. 2, 3 and 4, including output interface 16, tone knob 15, function knob 13, output channel knob 14, volume knob 12, play/toggle button 7 of rewinding, toggle switch 8 of playing/rewinding, take-up reel 6, magnetic head 1, height scale of magnetic head 2, notch of magnetic head 11, take-up reel bayonet 3, lead wire card pressing plate button 5, lead wire card pressing plate 4, supply reel 9 and safety pillar 10; the temperature control system comprises a first temperature detection device, a second temperature detection device and a mute cold and hot air blower, wherein the first temperature detection device and the second temperature detection device adopt Raytek MT4 infrared thermometers; RME Fireface UFX is adopted as the acquisition card;

the audio cable adopts SREXACT-SVC675 professional low-noise microphone cables (polyvinyl chloride PVC outer covers, 16X9 shielding layers are net-woven, the shielding rate is more than 95%, and OFC oxygen-free copper conductors are more than 60/0.1099.97%); a Neutrk-NP2X special large two-core TS plug (nickel-plated contact, nickel-plated shell);

under the condition that the playback equipment is ensured to work normally, the step 2 specifically comprises the following steps:

step 2.1: the tone knob 15 of the playback equipment turns to the off state, the power of the playback equipment is the off state;

step 2.2: connecting an acquisition card with a computer, configuring the acquisition card into a standby state, and enabling all buttons of the acquisition card to be in an initial state;

step 2.3: inspecting the magnetic head notch 11, and cleaning dust and dirt at the magnetic head notch 11; the method for cleaning the dust and dirt at the magnetic head notch 11 comprises the steps of using a toothbrush soaked in tetrachloride or absolute alcohol to scrub and clean the magnetic head notch 11 after a power supply is turned off;

step 2.4: inserting the positive electrode of the first end of the audio cable and the ground wire into the positive electrode 161 and the ground terminal 162 of the output interface 16, respectively, as shown in fig. 5, and satisfying the standard of the terminal, where the standard of the terminal is that the metal part of the connector of the audio cable is completely inserted into the corresponding port and is fixed stably, and the judgment standard of the fixation stability is that the audio cable is pulled by a force greater than 3N and less than 6N, and the connector is not loosened;

step 2.5: connecting the second end of the audio line to the input end of the acquisition card and meeting the standard of a terminal;

step 2.6: connecting the monitoring earphone with a collection card;

step 2.7: connecting a first temperature detection device and a mute cold and hot fan, wherein the first temperature detection device is configured to detect the temperature of the magnetic head notch 11; and the second temperature detection device is connected with the mute cold and hot air fan, the second temperature detection device is configured to detect the surface temperature of the steel wire at the inlet of the magnetic head 1, the surface temperature of the steel wire at the inlet of the magnetic head 1 is kept in a first temperature control range, the first temperature control range is 24-27 ℃, when the surface temperature of the steel wire at the inlet of the magnetic head 1 is not in the first temperature control range, the mute cold and hot air fan is automatically started, the mute cold and hot air fan is stopped until the surface temperature of the steel wire at the inlet of the magnetic head 1 is kept in the first temperature control range, and when the mute cold and hot air fan is started, the air outlet is not aligned with the steel wire at the inlet of the magnetic head 1.

And step 3: preheating the playback equipment; switching on a power supply of the playback equipment, rotating the tone knob 15, starting the power supply of the playback equipment, preheating the playback equipment, wherein the preheating time is 15-30 minutes, the standard of preheating completion is within a time period of 5 minutes or more, the time is preferably 7 minutes in the embodiment, and the temperature change of the magnetic head notch 11 is less than 0.4 ℃; when the temperature of the magnetic head notch 11 is more than or equal to 35 ℃, the mute cold and hot air blower can be automatically started until the temperature of the magnetic head notch 11 is less than or equal to 25.5 ℃, the mute cold and hot air blower is stopped, and when the mute cold and hot air blower is started, the air outlet is not aligned to the magnetic head notch 11.

And 4, step 4: installing a steel wire belt; the method specifically comprises the following steps:

step 4.1: wearing plastic gloves, and avoiding the direct touch of both hands on the steel wire in the whole installation process;

step 4.2: the steel wire belt is checked whether rust exists or a lead is lost, and the steel wire belt with the rust needs to be derusted firstly, wherein the derusting method comprises the steps of scraping the steel wire with the rust by using soft cloth or an ultra-pure steel wire group, soaking the soft cloth by using a derusting agent and then wiping the steel wire with the rust; the steel wire belt with the missing lead wire needs to be connected firstly; broken steel wires exist, and the broken steel wires need to be connected; the connecting method of the broken steel wires comprises the steps of buckling a flat knot at the wire head of the steel wires to be connected, and then tensioning and shearing off the redundant steel wires;

step 4.3: pressing a toggle button 7 for playing/rewinding, and toggling a toggle switch 8 for playing/rewinding to a rewinding state;

step 4.4: rotating the winding roll 6 to move the magnetic head 1 upwards until the top end of the magnetic head height scale 2 is leveled;

step 4.5: placing the steel wire disc on the wire supply disc 9, and pulling out the steel wire lead clockwise;

step 4.6: the steel wire must pass the magnetic head notch 11, and the lead must pass the winding roll bayonet 3; the lead clamping press plate 4 is lifted by pressing the lead clamping press plate button 5, a lead passes through the lead clamping press plate 4, and the lead is clamped by loosening the lead clamping press plate button 5; if the lead is too long, the steel wire does not enter the magnetic head notch 11, and the winding roll 6 can be rotated clockwise after the lead is clamped until the steel wire touches the magnetic head notch 11;

step 4.7: adjusting the wire supply disc 9 to enable the steel wire to be in a straightening state;

step 4.8: the play/rewind toggle switch 8 is toggled to an intermediate position.

And 5: adjusting the test tone; the method specifically comprises the following steps:

step 5.1: turning the tone knob 15, turning on the power supply of the playback equipment, and turning the knob to a proper gear;

step 5.2: the function knob 13 is pulled to a listening position;

step 5.3: according to the output port accessed by the audio cable in the step 2.3, rotating the output channel knob 14 to a corresponding gear;

step 5.4: turning the volume knob 12 until the volume is normally audible to the staff;

step 5.5: pressing the toggle button 7 for playing/rewinding, toggling the toggle switch 8 for playing/rewinding to the playing state, and starting playing;

step 5.6: in the sound testing process, a worker needs to determine whether the audio signal normally enters the earphone and the acquisition software, and if the audio signal is abnormal, the worker needs to check;

step 5.7: the volume knob 12 is rotated to control the volume until the peak value of the level amplitude of the collected audio signal is smaller than-3 dB, and the average value of the level amplitude RMS is between-30 dB and-10 dB; if the volume knob 12 is adjusted to the maximum, the peak value of the level amplitude of the collected audio still cannot reach-20 dB, the gain knob on the collection card is adjusted to gain, and the gain amplitude does not exceed 15 dB;

step 5.8: the sound testing time is not more than 3 minutes, the tape rewinding is restored after the sound testing is successful, and the adjustment parameters of the sound playing equipment, the acquisition card and the sampling recording software are kept unchanged.

Step 6: playback collection; configuring sampling parameters according to different contents of the steel wire recording tape to be sampled, wherein the sampling parameters comprise sampling frequency, sampling precision, sampling tone and sampling volume; the method specifically comprises the following steps:

step 6.1: opening an audio acquisition software Adobe Audio 3.0, and acquiring in a single track mode; the content of the steel wire recording tape to be sampled is divided into three types of songs, Chinese national drama songs and languages, and the content types of different steel wire recording tapes are respectively provided with sampling frequency, sampling precision, sampling tone and sampling volume; recording and collecting after leaving white for 3-5 seconds; the preferred configuration of the sampling parameters of this embodiment is as follows:

the sampling tone of songs is set to be 4.0-5.0, the embodiment is preferably 4.5, the sampling tone of Chinese ethnic opera songs is set to be 4.5-5.0, the embodiment is preferably 4.7, the sampling tone of languages is set to be 2.0-4.0, the embodiment is preferably 3.0;

the sampling volume of songs is set to be 0.8-1.5, the preferred embodiment is 1.0, the sampling volume of Chinese national folk operas is set to be 0.6-1.0, the preferred embodiment is 0.8, the sampling volume of languages is set to be 1.0-2.5, and the preferred embodiment is 1.5;

when the purpose of digitally converting the steel wire audio frequency file is to carry out playback and regeneration, the sampling frequency of songs is set to be 48kHz, the sampling precision of songs is set to be 16bit, the sampling frequency of Chinese national opera songs is set to be 48kHz, the sampling precision of Chinese national opera songs is set to be 16bit, the sampling frequency of languages is set to be 44.1kHz, and the sampling precision of languages is set to be 16 bit;

when the aim of digitally converting the steel wire audio frequency file is to carry out digital repair, the sampling frequency of songs is set to be 96kHz, the sampling precision of songs is set to be 24bit, the sampling frequency of Chinese national opera songs is set to be 96kHz, the sampling precision of Chinese national opera songs is set to be 24bit, the sampling frequency of languages is set to be 48kHz, and the sampling precision of languages is set to be 24 bit;

step 6.2: pressing a toggle button 7 for playing/rewinding, toggling a toggle switch 8 for playing/rewinding to a playing state, and starting playback acquisition;

step 6.3: in the playback acquisition process, a worker monitors whether the acquired audio signal is normal by using an earphone, and if the acquired audio signal is abnormal, the reason needs to be searched for to be checked; if the fault of sound reproduction interruption such as non-steel wire breakage occurs, sampling and recording are continued until the work is finished, and then fault analysis and processing are carried out;

step 6.4: after the playback is finished, the toggle button 7 for playing/rewinding is pressed, and the toggle switch 8 for playing/rewinding is toggled to the middle position;

step 6.5: and after leaving white for 3-5 seconds, closing the sampling and recording function of the audio software.

And 7: storing data; the method specifically comprises the following steps:

step 7.1: using audio acquisition software Adobe Audio 3.0 to store audio content, wherein the format of the digital file is wav; the digital file is coded into Windows PCM;

step 7.2: naming the digital file according to a naming rule;

step 7.3: recording information of an acquisition process; the recorded content comprises the metadata of the steel wire belt, the metadata of playback equipment, acquisition equipment and parameters, acquisition time and operators; the metadata of the steel wire belt comprises brands, materials and appearance characters; the playback equipment metadata comprises a brand and a model;

and 8: rewinding and reducing; the method specifically comprises the following steps:

step 8.1: turning the volume knob 12 to adjust the volume of the playback device to the lowest;

step 8.2: pressing a toggle button 7 for playing/rewinding, and toggling a toggle switch 8 for playing/rewinding to a rewinding state;

step 8.3: waiting for the end of rewinding;

step 8.4: when the rewinding is finished, the lead can poke the safety post 10 to make the playback equipment in a power-off state;

step 8.5: pressing the lead wire clamp press plate button 5 to loosen the lead wire clamp press plate 4, and taking out the lead wire from the lead wire clamp press plate 4;

step 8.6: taking out the leads from the bayonet 3 of the winding roll and the notch 11 of the magnetic head respectively, and taking the steel wire recording tape away from the wire supply roll 9;

step 8.7: the lead wire is clockwise wound on the steel wire recording tape, and the end of the lead wire is fixed on the paper surface of the brand label by the medical adhesive tape.

And step 9: the digital conversion work is finished; the method specifically comprises the following steps:

step 9.1: restoring a play/rewind toggle switch and a volume knob 12 of the playback equipment;

step 9.2: restoring a functional knob 13 on the acquisition card;

step 9.3: the tone knob 15 is rotated to the off position to turn off the power of the playback device.

By adopting the method of the embodiment, the first group of samples are sampled for four times, the hardware environment, the sampling parameters and the software tool of the four-time sampling are the same, and the audio sampling results when the surface temperature of the steel wire is controlled at 4 different temperatures are shown in table 1;

by adopting the method of the embodiment, the second group of samples are sampled for four times, the hardware environment, the sampling parameters and the software tool of the four-time sampling are the same, and the audio sampling results when the surface temperature of the steel wire is controlled at 4 different temperatures are shown in table 2;

TABLE 1 influence of surface temperature variation of first set of sample wires on digitally sampled audio signals

Serial number	Counting project names	Sample 1	Sample 2	Sample 3	Sample 4
						1	Surface temperature of steel wire	26.4℃	27.8℃	28.4℃	28.8℃
2	Minimum sample value	-20882	-16344	-15270	-9880
						3	Maximum sample value	19748	16754	10642	8403
4	Peak amplitude	-3.90dB	-5.82dB	-6.62dB	-10.40dB
						5	Samples that may overflow	0	0	0	0
6	DC offset	0％	0％	0％	0％
						7	RMS minimum value	-117.59dB	-136.97dB	-132.50dB	-134.53dB
8	Maximum value of RMS	-7.47dB	-10.04dB	-13.44dB	-15.70dB
						9	RMS average value	-13.94dB	16.44dB	-19.50dB	-21.59dB
10	RMS total	-13.16dB	15.66dB	-18.75dB	-20.85dB

TABLE 2 influence of the second set of sample wire surface temperature variations on the digitally sampled audio signals

Serial number	Counting project names	Sample 1	Sample 2	Sample 3	Sample 4
						1	Surface temperature of steel wire	26.6℃	29.2℃	31.2℃	32.8℃
2	Minimum sample value	-22408	-14517	-12647	-9614
						3	Maximum sample value	21351	13899	10897	8582
4	Peak amplitude	-3.29dB	-7.06dB	-8.26dB	-10.64dB
						5	Samples that may overflow	0	0	0	0
6	DC offset	0％	0％	0％	0％
						7	RMS minimum value	-115.26dB	-128.77dB	-125.25dB	-134.76dB
8	Maximum value of RMS	-6.65dB	-11.21dB	-13.71dB	-15.68dB
						9	RMS average value	-13.32dB	-17.36dB	-19.82dB	-21.54dB
10	RMS total	-12.52dB	16.60dB	-19.06dB	-20.80dB

By adopting the method of the embodiment, the sampling frequency is 44.1kHz, the frequency response graphs with the sampling accuracies of 8 bits and 16 bits are respectively shown in FIG. 6, the sampling frequency is 48kHz, the frequency response graphs with the sampling accuracies of 16 bits and 24 bits are respectively shown in FIG. 7, and it can be known from FIG. 6 and FIG. 7 that the frequency response curve with the sampling accuracy of 8 bits has obvious fluctuation and serious frequency distortion; the curves with the sampling precision of 16 bits and the sampling precision of 24 bits are basically consistent and have no obvious difference; particularly around the frequency at which the human ear is most sensitive (3kHz), the frequency response is essentially a straight line.

With the method of this embodiment, the influence on the total harmonic distortion when the sampling frequency is 44.1kHz and the sampling accuracies are 8 bits and 16 bits, respectively, and the influence on the harmonic distortion when the sampling frequency is 48kHz and the sampling accuracies are 16 bits and 24bi, respectively, are shown in table 3.

TABLE 3 influence of sampling frequency and sampling precision on Total harmonic distortion

	44.1kHz/8bit	44.1kHz/16bit	48kHz/16bit	48kHz/24bit
					Total harmonic distortion,%	68.918	0.00238	0.00226	0.00236
Intermodulation distortion,%	64.143	0.00820	0.00816	0.00621

The differences between the same sampling parameters and the contents of different steel wire tapes are shown in tables 4, 5 and 6 using the method of this example.

TABLE 4 comparison of sample content of the third set of samples to the difference in sampling parameters

TABLE 5 comparison of sample content and sample parameter differences for a fourth set of samples

TABLE 6 comparison of sample content for the fifth set of samples against the difference in sampling parameters

In tables 4, 5 and 6, RMS indicates the level amplitude of the digitally sampled audio signal, the average value of RMS is controlled between-30 dB and-10 dB, and the sampling quality and listening effect are relatively ideal, and it can be known from tables 4, 5 and 6 that different sampling parameters should be configured according to different contents of the steel wire recording tape to be sampled.

With the method of the present embodiment, the comparison of the signal statistics of the audio signal with the sampling duration of 90 ms in the digital conversion of the "binaural" and "monophonic" modes is shown in table 7, and table 8 and table 9, where the signal sampling values and the level amplitudes of the two are slightly different but substantially the same from the statistics in the table.

The two-channel digital sampling audio and the single-channel digital sampling audio are converted into two-channel audio, and compared with phase diagrams at the same time point position, the signal phase has no difference.

Therefore, the method of the embodiment not only does not reduce the quality of the digitally converted audio, but also saves the occupied space of the disk and improves the economic benefit.

TABLE 7 comparison of signal statistics for a sixth set of sample audio signals

Audio track	Maximum sample value	RMS total	RMS average value	DC offset
					Binaural-left channel	20336	-12.03dB	-12.53dB	0％
Binaural-right channel	20336	-12.03dB	-12.53dB	0％
					Single sound channel	20467	-12.19dB	-12.69dB	0％

TABLE 8 comparison of signal statistics for a seventh set of sample audio signals

Audio track	Maximum sample value	RMS total	RMS average value	DC offset
					Double soundTrack-left track	18017	-13.33dB	-13.80dB	0％
Binaural-right channel	18017	-13.33dB	-13.80dB	0％
					Single sound channel	20347	-12.11dB	-12.63dB	0％

TABLE 9 comparison of signal statistics for an eighth set of sample audio signals

Audio track	Maximum sample value	RMS total	RMS average value	DC offset
					Binaural-left channel	16896	-13.54dB	-14.00dB	-0.389％
Binaural-right channel	16896	-13.54dB	-14.00dB	-0.389％
					Single sound channel	20224	-12.28dB	-12.77dB	-0.389％

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims (9)

1. A method for digitally converting steel wire sound recordings, comprising the steps of:

step 1: pre-preparing a digital conversion environment;

step 2: installation and configuration of conversion equipment; the conversion equipment comprises playback equipment, a collection card, a computer, a monitoring earphone, an audio line and a temperature control system; the playback equipment comprises an output interface, a tone knob, a function knob, an output channel knob, a volume knob, a toggle button for playing/rewinding, a toggle switch for playing/rewinding, a winding roll, a magnetic head height scale, a magnetic head notch, a winding roll bayonet, a lead clamping press plate button, a lead clamping press plate, a wire supply roll and a safety post;

and step 3: preheating the playback equipment;

and 4, step 4: installing a steel wire belt;

and 5: adjusting the test tone;

step 6: playback collection; acquiring in a single track mode;

the step 6 comprises the following steps:

step 6.1: opening audio acquisition software, and acquiring in a single track mode; the content of the steel wire recording tape to be sampled is divided into three types of songs, Chinese national opera and languages, and the content types of different steel wire recording tapes are respectively provided with sampling frequency, sampling precision, sampling tone and sampling volume for recording and collecting; the sampling tone of the song class is set to be 4.0-5.0, the sampling tone of the Chinese ethnic opera class is set to be 4.5-5.0, and the sampling tone of the language class is set to be 2.0-4.0; the sampling volume of the songs is set to be 0.8-1.5, the sampling volume of the Chinese national drama songs is set to be 0.6-1.0, and the sampling volume of the language is set to be 1.0-2.5;

when the purpose of digitally converting the steel wire audio frequency archive is playback and regeneration, the sampling frequency of the songs is set to be 48kHz, the sampling precision of the songs is set to be 16 bits, the sampling frequency of the Chinese national drama songs is set to be 48kHz, the sampling precision of the Chinese national drama songs is set to be 16 bits, the sampling frequency of the language is set to be 44.1kHz, and the sampling precision of the language is set to be 16 bits;

when the aim of digitally converting the steel wire audio frequency file is to carry out digital repair, the sampling frequency of the songs is set to 96kHz, the sampling precision of the songs is set to 24bit, the sampling frequency of the Chinese national opera songs is set to 96kHz, the sampling precision of the Chinese national opera songs is set to 24bit, the sampling frequency of the language is set to 48kHz, and the sampling precision of the language is set to 24 bit;

step 6.2: pressing the toggle button of the playing/rewinding, toggling the toggle switch of the playing/rewinding to a playing state, and starting playback acquisition;

step 6.3: in the playback acquisition process, a worker monitors whether the acquired audio signal is normal by using an earphone, and if the acquired audio signal is abnormal, the reason needs to be searched for to be checked; if the fault that the sound reproduction is interrupted due to non-steel wire breakage occurs, sampling and recording are continued until the work is finished, and then fault analysis and processing are carried out;

step 6.4: after the playback is finished, pressing the toggle button of the play/rewind to toggle the toggle switch of the play/rewind to the middle position;

step 6.5: after leaving white for 3-5 seconds, closing the sampling and recording functions of the audio software;

and 7: storing data;

and 8: rewinding and reducing;

and step 9: the digital conversion work is completed.

2. The method for digitally converting a steel wire audio recording according to claim 1, wherein said step 1 comprises the steps of:

step 1.1: the environment temperature of a digital conversion working place is controlled between 20 ℃ and 27 ℃ by adopting a cooling and heating air conditioner, and the humidity is controlled between 55 percent and 70 percent;

step 1.2: workers wear dustproof clothes, dustproof shoes, dustproof hats and medical plastic gloves;

step 1.3: the sound reproduction equipment is placed on a stable working platform, the working platform is a solid rigid body, the working platform comprises a damping device, and the damping device is made of plastic or rubber;

step 1.4: a noise source and a vibration source are not arranged near the working platform; the noise standard value of the noise source is more than or equal to 70dB, and the vibration intensity of the vibration source is more than 0.71 mm/s;

step 1.5: during digital sampling, the manual touch of a workbench or conversion equipment is absolutely avoided, so that signal distortion caused by vibration is prevented.

3. The method for digitally converting a steel wire audio recording according to claim 1, wherein said step 2 comprises the steps of:

step 2.1: the tone knob of the playback equipment is turned to be in an off state, and the power supply of the playback equipment is in the off state;

step 2.2: connecting the acquisition card with the computer, wherein the acquisition card is configured to be in a standby state, and all buttons of the acquisition card are in an initial state;

step 2.3: inspecting the notch of the magnetic head, and cleaning dust and dirt at the notch of the magnetic head; the method for cleaning the dust and dirt at the notch of the magnetic head comprises the steps of using a toothbrush soaked in tetrachloride or absolute alcohol to scrub and clean the notch of the magnetic head after a power supply is turned off;

step 2.4: respectively inserting the positive electrode of the first end of the audio cable and the grounding wire into the positive electrode end and the grounding end of the output interface, and meeting the wiring terminal standard, wherein the wiring terminal standard is that the metal parts of the joint of the audio cable are all inserted into the corresponding ports and are fixed and stable;

step 2.5: connecting the second end of the audio line to the input end of the acquisition card, and meeting the standard of a terminal;

step 2.6: connecting the monitoring earphone with the acquisition card;

step 2.7: and the temperature control system is connected and used for controlling the temperature of the notch of the magnetic head and the surface temperature of the steel wire at the inlet of the magnetic head, and the surface temperature of the steel wire at the inlet of the magnetic head is kept within a first temperature control range, wherein the first temperature control range is 24-27 ℃.

4. The method for digitally converting a steel wire audio recording according to claim 1, wherein said step 3 comprises the steps of: switching on a power supply of the playback equipment, rotating the tone knob, starting the power supply of the playback equipment, and preheating the playback equipment, wherein the preheating time is 15-30 minutes, and the preheating completion standard is that the temperature change of the notch of the magnetic head is less than 0.4 ℃ in a time period of 5 minutes or more; and when the temperature of the notch of the magnetic head is more than or equal to 35 ℃, the temperature control system is automatically started until the temperature of the notch of the magnetic head is less than or equal to 25.5 ℃, and then the temperature control system is stopped.

5. The method for digitally converting a steel wire audio recording according to claim 1, wherein said step 4 comprises the steps of:

step 4.1: wearing plastic gloves, and avoiding the direct touch of both hands on the steel wire in the whole installation process;

step 4.2: checking a steel wire belt to determine whether rust exists or a lead is lost, and removing rust of the steel wire belt with the rust firstly, wherein the rust removing method comprises the steps of scraping the steel wire with the rust by using an ultra-pure steel wire group, soaking soft cloth by using a rust remover and then wiping the steel wire with the rust; the steel wire belt with the missing lead wire needs to be connected firstly; broken steel wires exist, and the broken steel wires need to be connected; the connecting method of the broken steel wires comprises the steps of buckling a flat knot at the wire head of the steel wires to be connected, and then tensioning and shearing off the redundant steel wires;

step 4.3: pressing the toggle button of the playing/rewinding, and toggling the toggle switch of the playing/rewinding to a rewinding state;

step 4.4: rotating the winding roll to enable the magnetic head to move upwards until the winding roll is level to the top end of the height scale of the magnetic head;

step 4.5: placing the steel wire disc on the wire supply disc, and pulling out a steel wire lead in a clockwise direction;

step 4.6: the steel wire must pass through the magnetic head notch, and the lead must pass through the winding roll bayonet; the lead clamping press plate is lifted by pressing the lead clamping press plate button, a lead passes through the lead clamping press plate, and the lead is clamped by loosening the lead clamping press plate button;

step 4.7: adjusting the wire supply disc to enable the steel wire to be in a straightening state;

step 4.8: and the toggle switch for playing/rewinding is toggled to the middle position.

6. A method for digitally converting a steel wire audio recording according to claim 3, wherein said step 5 comprises the steps of:

step 5.1: turning the tone knob, turning on the power supply of the playback equipment, and turning the knob to a proper gear;

step 5.2: the function knob is pulled to a listening gear;

step 5.3: according to the output port accessed by the audio cable in the step 2.3, rotating the output channel knob to a corresponding gear;

step 5.4: rotating the volume knob until the volume is normally audible to a worker;

step 5.5: pressing the toggle button of the playing/rewinding, toggling the toggle switch of the playing/rewinding to a playing state, and starting playing;

step 5.6: in the sound testing process, a worker needs to determine whether the audio signal normally enters the earphone and the acquisition software, and if the audio signal is abnormal, the worker needs to check;

step 5.7: the volume knob is rotated to control the volume until the peak value of the level amplitude of the collected audio signal is smaller than-3 dB, and the average value of the level amplitude RMS is between-30 dB and-10 dB; if the volume knob is adjusted to the maximum, the peak value of the level amplitude of the collected audio still cannot reach-20 dB, the gain knob on the collection card is adjusted to gain, and the gain amplitude does not exceed 15 dB;

step 5.8: the sound testing time is not more than 3 minutes, the tape rewinding is restored after the sound testing is successful, and the adjustment parameters of the sound playing equipment, the acquisition card and the sampling recording software are kept unchanged.

7. The method for digitally converting steel wire audio records according to claim 1, wherein said step 7 comprises the steps of:

step 7.1: audio acquisition software is used for storing audio contents;

step 7.2: naming the digital file according to a naming rule;

step 7.3: and recording information of the acquisition process.

8. The method for digitally converting a steel wire audio recording according to claim 1 wherein said step 8 comprises the steps of:

step 8.1: turning the volume knob to adjust the volume of the playback equipment to the lowest;

step 8.2: pressing the toggle button of the playing/rewinding, and toggling the toggle switch of the playing/rewinding to a rewinding state;

step 8.3: waiting for the end of rewinding;

step 8.4: when the rewinding is finished, the lead can poke the safety post to enable the playback equipment to be in a power-off state;

step 8.5: pressing the lead clamping press plate button to loosen the lead clamping press plate and taking a lead out of the lead clamping press plate;

step 8.6: taking out the lead wires from the bayonet of the winding roll and the notch of the magnetic head respectively, and taking the steel wire recording tape away from the wire supply roll;

step 8.7: the lead is clockwise wound on the steel wire recording tape, and the lead head is fixed by the medical adhesive tape.

9. The method for digitally converting a steel wire audio recording according to claim 1, wherein said step 9 comprises the steps of:

step 9.1: restoring the playing/rewinding toggle switch and the volume knob of the playback equipment;

step 9.2: restoring a functional knob on the acquisition card;

step 9.3: and rotating the tone knob to a closing gear to close the power supply of the playback equipment.

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