CN1897054A - Device and method for transmitting alarm according various acoustic signals - Google Patents

Abstract

A transmission device capable of issuing alarms according to sound types, comprising a sound receiver capable of receiving ambient sound, a database storing characteristics of various sounds, a sound recognizer, an emergency prompter and a sound mixer. The sound recognizer can extract the characteristics of the environmental sound, and compare the characteristics of the environmental sound with the characteristics of various types of sounds in the database to determine whether the environmental sound belongs to the sound category in the database. And when the sound recognizer determines that the ambient sound belongs to the sound category in the database, the emergency prompter outputs a warning sound. The sound mixer can choose not to output the sound of the sound playing device but output the warning sound instead, or choose to synthesize the warning sound with the sound played by the sound playing device and then output it.

Description

Transmission device and method capable of issuing alarms according to sound types

technical field

The invention relates to a sound transmission device and method, in particular to a transmission device and method that can issue an alarm according to the type of sound.

Background technique

Portable audio playback devices, such as CD players and mp3 players, have been widely used by the public in today's society. And the user generally listens to the music of the Walkman with an earphone or a headset.

Users wearing earphones often listen to the music played by the earphones while walking on the street, but these users often only focus on listening to the music and ignore the external warning sounds (such as: car horns), or The external warning sound cannot be heard because the volume of the sound from the earphone is too loud. But if the user fails to respond to the external warning sound in time, dangerous accidents may occur.

Referring to Fig. 4, in order to solve the above-mentioned problem, U.S. Patent No.US6782106B1 discloses a kind of sound transmission device 14, and this sound transmission device 14 is electrically connected with a sound player (not shown in the figure) and an earphone/earphone , and includes a microphone 20 , a volume filter 22 and a mixer 28 .

The microphone 20 can receive the ambient sound around the user and output it to the volume filter 22 .

And the volume filter 22 is electrically connected with the sound player and the mixer 28, and simultaneously receives the ambient sound output by the sound player and the microphone 20, and when the ambient sound output by the sound player and the microphone 20 When the volume of the ambient sound is greater than a certain value, the volume filter 22 can output the ambient sound to the mixer 28. The size of the specific value can be set by the user.

The sound mixer 28 synthesizes the sound sent by the sound playing device and the sound sent by the volume filter 22, and outputs the synthesized sound to the earphone, and the synthesized sound is played by the earphone to remind the user .

However, the known device 14 assumes that the volume of the warning sound in the environment must be greater than the specified value. However, there are often many sounds in the environment that are louder than this specific value but are not dangerous, such as the sound of radio or music played in a department store. The known sound transmission device 14 will regard these sounds as warning sounds and constantly remind the user, which will cause great trouble in use. In addition, the volume of many warning sounds in the environment is often not very loud, such as bicycle bells, but the known volume filter 22 filters out these warning sounds with low volume, and loses the purpose of warning users . Therefore, one of the methods to solve the known problem is to judge whether the environmental sound is dangerous based on the true meaning represented by the environmental sound, rather than judging by the volume of the environmental sound.

Contents of the invention

Therefore, the object of the present invention is to provide a transmission device that can issue an alarm according to the type of sound. By.

Another object of the present invention is to provide a transmission method that can issue an alarm according to the type of sound. The method can correctly determine the type of environmental sound, and when the environmental sound is indeed a dangerous sound, an alarm is issued to notify the user.

Therefore, the transmission device that can issue an alarm according to the type of sound of the present invention is suitable for reminding users who listen to the sound with earphones, and the sound sent by the earphone is produced by a sound playback device, and the transmission device that can issue an alarm according to the type of sound Contains sound receivers, databases, sound recognizers, emergency alerters, and sound mixers.

The sound receiver can receive the ambient sound around the user and output it to the sound recognizer. The database stores a variety of features of sounds that should be noted. And the sound recognizer can receive the environmental sound output by the sound receiver, and can extract the characteristics of the environmental sound, and compare the characteristics of the environmental sound with the characteristics of various sounds in the database to judge whether the environmental sound belongs to The sound categories in this database.

The emergency prompter includes a noise processing unit, a warning unit and a selection unit. The selection unit is electrically connected to the sound recognizer, the warning unit and the noise processing unit, and receives the ambient sound from the sound recognizer and the result of discrimination, and when the sound recognizer judges that the ambient sound does not belong to When the sound category in the database is selected, the selection unit sends the ambient sound to the noise processing unit, and the noise processing unit sends the ambient sound and its inverse sound wave to the mixer.

And when the sound recognizer judges that the ambient sound belongs to the sound category in the database, the selection unit selects the noise processing unit or the warning unit to output the warning sound, if the selection unit selects the noise processing unit, Then the noise processing unit is about to adjust the volume of the ambient sound as the warning sound, and output it to the mixer, and if the selection unit selects the warning unit, the warning unit is selected according to the judgment result of the sound recognizer. Corresponding and pre-made alarm sound, and output the alarm sound to the mixer.

The sound mixer can receive the sound of the sound playing device and the warning sound output by the emergency prompter, and can choose not to output the sound of the sound playing device but output the warning sound, or choose to combine the warning sound with the The sound played by the sound playing device is synthesized and output.

And the transmission method that can send out the alarm according to the sound type of the present invention comprises the following steps:

(A) receiving ambient sound;

(B) extracting the feature of the ambient sound;

(C) comparing the characteristics of the environmental sound with the characteristics of a variety of sounds that should be paid attention to, so as to determine whether the environmental sound belongs to the sound category that should be paid attention to; and

(D) When the ambient sound belongs to the sound category that should be paid attention to, stop outputting the sound of the sound playback device to the earphone or earphone, and instead output a warning sound, or combine the warning sound with the sound playback device. The sound is synthesized and output.

Description of drawings

Fig. 1 is a block diagram of a transmission device that can send an alarm according to the type of sound according to the present invention;

FIG. 2 is an acoustic diagram illustrating ambient sound, anti-phase sound waves of the ambient sound, and summed sound waves; and

Fig. 3 is the flow chart of the transmission method of the present invention that can issue an alarm according to the type of sound; and

Fig. 4 is a block diagram of a known sound transmission device.

Detailed ways

The foregoing and other technical content, features and effects of the present invention will be clearly presented in the following detailed description of preferred embodiments with reference to the drawings.

Referring to Fig. 1, the preferred embodiment of the transmission device 3 that can send an alarm according to the type of sound of the present invention is suitable for reminding the user that the ambient sound that should be paid attention to is given to the user who receives the sound played by the sound playback device 7 with an earphone 9, and the transmission device 3 includes a sound receiver 31 , a sound recognizer 32 , a database 33 , an emergency reminder 34 , a preference setter 35 , a sound mixer 36 and an error detector 37 .

The sound receiver 31 can receive the ambient sound around the user and output it to the sound recognizer 32, and the sound receiver 31 can be a microphone, but the present invention is not limited thereto, but other receivers can also be used. device.

The database 33 stores features of a variety of sounds with urgent and dangerous meanings, such as features of siren-like sounds, brake-like sounds, horn-like sounds, and the like. In this embodiment, the feature of each sound refers to the feature vector analyzed by the Mel-scale Frequency Cepstral Coefficients (MFCC) method, but it is not limited to this, and the sound can also be used The Zero Crossing Rate (ZCR for short) or sound energy of the signal is used as the characteristic of the sound signal.

The Mel cepstrum parameter method can refer to "Fundamentals of Speech Recognition" published by L.Rabiner and B.-H.Juang in Prentice Hall in 1993. This method mainly uses Fourier Transform to transform the sound signal from time to time The Time Domain (Time Domain) signal is converted into a Frequency Domain (Frequency Domain) signal, and the Frequency Domain signal represents the energy of the sound signal at each frequency. Then, multiple sets of triangular band-pass filters (Triangular Band-pass Filters) covering different frequency ranges are used to extract the energy values of the corresponding frequency ranges, and one set of triangular band-pass filters covers what human hearing can sense. sound frequency range, and each triangular bandpass filter multiplies the energy value with different weightings to obtain a characteristic value representing the frequency range, so it is possible to obtain as many triangular bandpass filters as there are eigenvalues, and take the multiple eigenvalues as a set of eigenvectors that can represent the sound.

The sound recognizer 32 is electrically connected to the database 33 and the emergency prompter 34, and receives the ambient sound output by the sound receiver 31, the sound recognizer 32 can extract the feature vector of the ambient sound, and compare the feature vector with The feature vectors of various sounds in the database 33 are used to judge whether the environmental sound belongs to the sound category in the database 33 , and after the judgment is completed, the environmental sound and the judgment result are output to the emergency prompter 34 .

In the present embodiment, the method for comparing the ambient sound with the feature vector stored in the database 33 by the sound recognizer 32 is the Mahalanobis distance method (MahalanobisDistance), which is disclosed in S.-T .Bow in "Pattern Recognition" published by Jwang Yuan in 1984. The method is mainly to calculate the Euclidian distance (EuclidianDistance) between the feature vector of the environmental sound and the feature vectors of various sounds stored in the database 33 . And in the process of calculating the distance, the Mahalanobis distance method also calculates the variation value (Variance) of the eigenvector. And when the Euclidean distance is sufficiently small, it means that the environmental sound signal conforms to one of the types of sound in the database 33 .

But this sound recognizer 32 also can use other methods to compare the feature vector stored in the environmental sound and this database 33, as: L.Rabiner and B.-H.Juang are written and published by Prentice Hall in 1993 "Fundamentals of Speech Recognition" said hidden Markov model (Hidden Markov Models) to judge, but the present invention is not limited thereto.

The emergency prompter 34 includes a selection unit 341 , a warning unit 342 and a noise processing unit 343 . The selection unit 341 is electrically connected to the sound recognizer 32, the warning unit 342, the noise processing unit 343 and the preference setter 35, and receives the ambient sound and the result judged by the sound recognizer 32, and in the When the sound recognizer 32 determines that the ambient sound does not belong to the dangerous category, the selection unit 341 sends the ambient sound to the noise processing unit 343 .

And when the sound recognizer 32 judges that the ambient sound belongs to dangerous sound, the selection unit 341 can choose to send the result judged by the sound recognizer 32 to the warning unit 342 to order the warning unit 342 to act; Or the selection unit 341 can select to send the ambient sound to the noise processing unit 343 to command the noise processing unit 343 to act.

The warning unit 342 is electrically connected with the selection unit 341 and the mixer 36, and can output a warning sound, and the warning sound can be set according to the user's preference, such as: when the ambient sound is the sound of brakes, it can be pre-stored Voice: "Caution has a car" as the warning sound, or when the ambient sound is a siren-like sound, a prestored continuous rapid beeping sound can be used as the warning sound. When the warning unit 342 receives an action command from the selection unit 341 , it will output a warning sound corresponding to the ambient sound to the mixer 36 .

The noise processing unit 343 is electrically connected to the selection unit 341 and the sound mixer 36 , and can receive the ambient sound output by the selection unit 341 . And when the ambient sound does not belong to the sound category of the database 33, the ambient sound and its inverse sound wave are output to the mixer 36, and the method of generating the inverse sound wave will be described in detail later. And when the ambient sound belongs to the sound category of the database 33 and the command from the selection unit 341 is received, the volume-adjusted ambient sound is used as the warning sound, and the warning sound is output to the mixer 36 .

The sound mixer 36 is electrically connected with the sound player 7 and the earphone 9, and when receiving the warning sound from the warning unit 342 or the noise processing unit 343, it can suspend receiving the sound played by the sound player 7. Instead, the warning sound is output to the earphone 9 to remind the user that there is a dangerous situation around. In addition, the sound mixer 36 can also synthesize the sound output by the sound player 7 with the warning sound before outputting To the earphone 9, it is set according to the user's preference.

The preference setter 35 is electrically connected to the selection unit 341 and the sound mixer 36, and can control the sound mixer 36 to use the warning sound and the sound output by the sound playback device 7 according to the user's settings. The mode of synthesizing and outputting again; or the mode of suspending receiving the sound played by the sound player 7 and outputting the warning sound to the earphone 9 instead. In addition, the preference setter 35 can also control the selection unit 341 to select the warning sound output by the warning unit 342 or the noise processing unit 343 when the environmental sound is a dangerous sound according to the setting of the user.

When the ambient sound does not belong to the sound category of the database 33, in order for the user to still normally listen to the sound output by the sound playback device 7, the interference of the ambient sound to the sound output by the sound playback device 7 must be eliminated. In a preferred embodiment of the present invention, the noise processing unit 343 adopts Automatic Noise Cancel (ANC) technology to eliminate ambient sounds that do not belong to the sound category of the database 33, but the present invention is not limited thereto. Referring to FIG. 2 , the ANC method is to generate the anti-phase sound wave of the ambient sound, so that the total sound wave after adding the ambient sound and its anti-phase sound wave approaches zero.

Referring back to FIG. 1 , the error detector 37 is a microphone placed around the earphone 9 . And when the process of starting the warm-up of the sound player 7, or when the sound player 7 converted the music tracks played, the sound player 7 had no sound output. At this time, the error detector 37 can receive the total sound wave of the ambient sound and its antiphase sound wave, and output the total sound wave to the noise processing unit 343 .

When the anti-phase sound wave and the ambient sound cannot be completely canceled out, the noise processing unit 343 may modify the anti-phase sound wave of the ambient sound with a non-zero total sound wave, so as to completely eliminate the ambient sound.

Cooperate with referring to Fig. 3, the transmission method that can send out the alarm according to the sound type of the present invention comprises the following steps:

Step 401, the sound receiver 31 receives ambient sound.

In step 402, the sound recognizer 32 extracts features of the ambient sound.

Step 403 , the sound recognizer 32 compares the feature of the ambient sound with the various sound features in the database 33 to determine the category of the ambient sound. If the ambient sound does not belong to the sound category in the database 33, then skip to step 410, indicating that the sound does not have emergency meaning. If the ambient sound belongs to the sound category in the database 33 , then skip to step 404 .

Step 404 determines whether the selection unit 341 will select the warning unit 342 to use a pre-made sound as the warning sound according to the setting value of the preference setter 35 . If yes, skip to step 405 . If not, skip to step 406 to select the noise processing unit 343 .

Step 405 , the warning unit 342 sends out a pre-made sound to the mixer 36 as the warning sound, and then executes step 407 .

Step 406 , the noise processing unit 343 stops generating the anti-phase sound wave of the ambient sound, and outputs the ambient sound to the mixer 36 as the warning sound, and then executes step 407 .

Step 407 is to determine whether the sound mixer 36 is to suspend receiving the sound played by the sound player 7 according to the setting value of the preference setter 35 . If yes, skip to step 409 . If not, go to step 408 .

Step 408 , the sound mixer 36 synthesizes the warning sound with the sound of the sound player 7 and outputs it, and skips to step 401 .

Step 409 , the mixer 36 suspends receiving the sound from the sound playing device 7 , outputs the warning sound separately, and skips to step 401 .

Step 410 , the noise processing unit 343 generates an anti-phase sound wave of the ambient sound to offset the ambient sound, and then executes step 411 .

Step 411 , the mixer 36 receives the anti-phase sound wave of the ambient sound, synthesizes the anti-phase sound wave of the ambient sound with the sound of the sound playing device 7 and outputs it, and skips to step 401 .

In summary, the present invention utilizes the sound recognizer 32 to determine whether the ambient sound matches the sound category in the database 33 . And when this environmental sound does not belong to the sound category of this database 33, then eliminate this environmental sound with the anti-phase sound wave of this environmental sound, make the user simply only hear the sound that this sound player 7 produces; And in this When the environmental sound belongs to the sound category of the database 33, the sound of user preference or the environmental sound is used as the warning sound, and the sound of the sound playing device 7 is suspended to play the warning sound, or the warning sound After being synthesized with the sound of the sound playing device 7, it is played out to notify the user to pay attention. Therefore, the sound in the environment that requires the user's attention can be reliably identified, and the purpose of the present invention is achieved.

What has been described above is only the preferred embodiment of the present invention, but can not limit the scope of implementation of the present invention with this, and those skilled in the art can simply make the content of the present invention without departing from the spirit and scope defined by the appended claims. Equivalent changes and modifications all fall within the scope of the present invention.

Claims (29)

1. A transmission device that can issue an alarm according to the type of sound, and is suitable for reminding users who use earphones or headphones to receive the sound played by the sound playback device to pay attention to environmental sounds, and the transmission device includes: The sound receiver receives the ambient sound around the user; A database that stores a variety of characteristics of sounds that should be paid attention to; The sound recognizer receives the environmental sound output by the sound receiver and extracts the characteristics of the environmental sound, and compares the characteristics of the environmental sound with the characteristics of various sounds in the database to determine whether the environmental sound belongs to the sound in the database category, and output the result of the judgment; An emergency prompter is electrically connected to the sound recognizer, and outputs a warning sound when the sound recognizer determines that the ambient sound belongs to the sound category in the database; and The sound mixer is electrically connected to the emergency prompter, and can receive the sound of the sound playing device and the warning sound output by the emergency prompter, and when the sound recognizer judges that the environmental sound belongs to the sound category in the database, Stop outputting the sound of the sound playing device and output the warning sound instead, or synthesize the warning sound with the sound played by the sound playing device and output it. 2. The transmission device capable of sending out alarms according to the type of sound according to claim 1, further comprising a preference setting device, which can set the mixer so that the mixer chooses to suspend outputting the sound The sound of the playing device is changed to output the warning sound, or the warning sound is selected to be synthesized with the sound of the sound playing device and then output. 3. The transmission device capable of issuing an alarm according to the type of sound according to claim 1, wherein the emergency prompter includes a warning unit, and the warning unit can receive the judgment result output by the sound recognizer, and select the corresponding sound according to the judgment result. corresponding and pre-made alarm sound, and output the alarm sound to the mixer. 4. The transmission device according to claim 1, wherein the emergency prompter includes a noise processing unit, and when the ambient sound does not belong to the sound category in the database, the noise processing unit then receiving the ambient sound output by the sound recognizer, and sending the ambient sound and its inverse sound wave to the mixer; and when the ambient sound belongs to the sound category in the database, the noise processing unit can adjust the volume The ambient sound is used as the first warning sound. 5. The transmission device capable of sending out an alarm according to the type of sound according to claim 4, further comprising an error detector, which can receive the ambient sound and the anti-phase sound wave when the sound playback device has no sound output and output the total sound wave to the noise processing unit for correction by the noise processing unit. 6. The transmission device capable of issuing an alarm according to the type of sound according to claim 1, wherein the emergency prompter includes a noise processing unit, a warning unit and a selection unit, and the selection unit is connected with the sound recognizer, the warning unit and the The noise processing unit is electrically connected, and receives the environmental sound from the sound recognizer and the result of discrimination, and when the sound recognizer judges that the environmental sound does not belong to the sound category in the database, the selection unit will The ambient sound is sent to the noise processing unit, and the noise processing unit sends the ambient sound and its anti-phase sound wave to the mixer, and when the sound recognizer judges that the ambient sound belongs to the sound category in the database, The selection unit selects the noise processing unit or the warning unit to output the warning sound, if the selection unit selects the noise processing unit, the noise processing unit will use the volume-adjusted ambient sound as the warning sound, and output to the sound mixer, and if the selection unit selects the warning unit, the warning unit selects the corresponding and pre-made warning sound according to the judgment result of the sound recognizer, and outputs the warning sound to the sound mixer device. 7. The transmission device capable of sending out alarms according to the type of sound according to claim 6, further comprising a preference setting device, which can set the mixer so that the mixer suspends outputting the sound playback The sound of the device can be changed to output the warning sound, or choose to synthesize the warning sound with the sound of the sound playback device to output; and the preference setting device can also set the selection unit to select the warning unit or the noise The processing unit outputs the warning sound. 8. The transmission device capable of sending out an alarm according to the type of sound according to claim 6, further comprising an error detector, which can receive the ambient sound and the anti-phase sound wave when the sound playback device has no sound output and output the total sound wave to the noise processing unit for correction by the noise processing unit. 9. The transmission device capable of issuing an alarm according to the type of sound according to claim 1, wherein the sound recognizer uses the eigenvector of the sound signal analyzed by the Mel cepstrum parameter method to represent the feature of the sound signal . 10. The transmission device capable of issuing an alarm according to the type of sound according to claim 1, wherein the sound recognizer calculates the number of zero crossings or sound energy of the sound signal as the feature of the sound signal. 11. The transmission device according to claim 9 or 10 that can send out alarms according to the type of sound, wherein the sound recognizer compares the characteristics of the ambient sound with the characteristics of various types of sounds in the database. Bias distance method. 12. A sound playback system that can send out alarms according to the type of sound, and is suitable for reminding users who use earphones or headphones to receive the sound played by the system to pay attention to environmental sounds. The sound playback system includes: A sound playing device for outputting sound; The sound receiver is used to receive the ambient sound around the user; a database for storing features of a variety of sounds that should be noted; The sound recognizer receives the environmental sound output by the sound receiver and extracts the characteristics of the environmental sound, and compares the characteristics of the environmental sound with the characteristics of various sounds in the database to determine whether the environmental sound belongs to the sound in the database category, and output the result of the judgment; An emergency prompter is electrically connected to the sound recognizer, and outputs a warning sound when the sound recognizer determines that the ambient sound belongs to the sound category in the database; and The sound mixer is electrically connected to the emergency prompter, and can receive the sound of the sound playing device and the warning sound output by the emergency prompter, and when the sound recognizer judges that the environmental sound belongs to the sound category in the database, Stop outputting the sound of the sound playing device and output the warning sound instead, or synthesize the warning sound with the sound played by the sound playing device and output it. 13. The sound playing system according to claim 12, which can send an alarm according to the type of sound, further comprising a preference setting device, which can set the mixer so that the mixer chooses to suspend outputting the The sound of the sound playing device can be changed to output the warning sound, or choose to synthesize the warning sound with the sound of the sound playing device to output. 14. The sound playing system capable of issuing an alarm according to the type of sound according to claim 12, wherein the emergency prompter includes a warning unit, the warning unit can receive the judgment result output by the sound recognizer, and select according to the judgment result Corresponding and pre-made alarm sound, and output the alarm sound to the mixer. 15. The sound playing system capable of issuing an alarm according to the type of sound according to claim 12, wherein the emergency prompter includes a noise processing unit, and when the ambient sound does not belong to the sound category in the database, the noise processing unit Then it will receive the ambient sound output by the sound recognizer, and send the ambient sound and its anti-phase sound wave to the mixer; and when the ambient sound belongs to the sound category in the database, the noise processing unit can adjust the The ambient sound after the volume is used as the warning sound. 16. The sound playing system capable of giving an alarm according to the sound type according to claim 15, further comprising an error detector, which can receive the ambient sound and the inverse phase when the sound playing device has no sound output. The total sound waves of the sound waves are output to the noise processing unit for the noise processing unit to modify the output. 17. The sound playing system capable of issuing an alarm according to the type of sound according to claim 12, wherein the emergency prompter includes a noise processing unit, a warning unit and a selection unit, and the selection unit is connected with the sound recognizer, the warning unit and the selection unit. The noise processing unit is electrically connected to receive the ambient sound from the sound recognizer and the result of discrimination, and when the sound recognizer judges that the ambient sound does not belong to the sound category in the database, the selection unit will The ambient sound is sent to the noise processing unit, and the noise processing unit sends the ambient sound and its inverse sound wave to the mixer, and when the sound recognizer judges that the ambient sound belongs to the sound category in the database , the selection unit selects the noise processing unit or the warning unit to output the warning sound, if the selection unit selects the noise processing unit, the noise processing unit will use the volume-adjusted ambient sound as the warning sound, And output to the sound mixer, and if the selection unit selects the warning unit, the warning unit selects the corresponding and pre-made warning sound according to the judgment result of the sound recognizer, and outputs the warning sound to the mixer speaker. 18. The sound playing system capable of issuing alarms according to the type of sound according to claim 17, further comprising a preference setting device, which can set the mixer so that the mixer suspends outputting the sound Play the sound of the device to change the output of the warning sound, or choose to synthesize the warning sound with the sound of the sound playback device to output; and the preference setter can also set the selection unit to select the warning unit or the The noise processing unit outputs the warning sound. 19. The sound playback system capable of issuing an alarm according to the type of sound according to claim 17, further comprising an error detector, which can receive the ambient sound and the inverse phase when the sound playback device has no sound output. summing the sound waves, and outputting the summed sound waves to the noise processing unit for correction by the noise processing unit. 20. The sound playing system capable of sending out alarms according to the sound type according to claim 12, wherein the sound recognizer is to represent the sound signal by using the eigenvector of the sound signal analyzed by the Mel cepstrum parameter method feature. 21. The sound playback system capable of issuing alarms according to sound types according to claim 12, wherein the sound recognizer calculates the number of zero crossings or sound energy of the sound signal as the feature of the sound signal. 22. The sound playing system according to claim 20 or 21, which can give an alarm according to the type of sound, wherein the method for comparing the characteristics of the environmental sound with the characteristics of various types of sounds in the database by the sound recognizer is Maharaja Nobis distance method. 23. A transmission method capable of issuing an alarm according to the type of sound, suitable for reminding users who use earphones or earphones to receive the sound played by the sound playback device to pay attention to the environmental sound, comprising the following steps: (A) receiving ambient sound; (B) extracting the feature of the ambient sound; (C) comparing the characteristics of the ambient sound with the characteristics of a plurality of noteworthy sounds to determine whether the ambient sound belongs to the noteworthy sound category; and (D) When the ambient sound belongs to the sound category that should be paid attention to, stop outputting the sound of the sound playback device to the earphone or earphone, and instead output a warning sound, or combine the warning sound with the sound playback device The sound is synthesized and output. 24. The sound transmission method capable of prompting environmental sound according to claim 23, wherein in step (B), the feature vector of the sound signal is analyzed by using Mel cepstrum parameters to represent the characteristics of the environmental sound. 25. The sound transmission method capable of prompting ambient sound according to claim 23, wherein in step (B), the zero-crossing times or sound energy of the ambient sound is calculated as the feature of the ambient sound. 26. The sound transmission method capable of prompting environmental sounds according to claim 24 or 25, wherein, in step (C), the Mahalanobis distance method is used to compare the characteristics of the environmental sound with the plurality of noticeable characteristics of the sound. 27. The sound transmission method capable of prompting environmental sound according to claim 23, wherein in step (D), a pre-made sound is used as the warning sound. 28. The sound transmission method capable of prompting environmental sound according to claim 23, wherein, in step (D), when the environmental sound belongs to the sound category that should be paid attention to, the environmental sound is directly used as the warning sound output . 29. The sound transmission method capable of prompting environmental sound according to claim 23, wherein, in step (D), when the environmental sound does not belong to the sound category that should be paid attention to, the environmental sound and its inverse sound wave are output to the headset or headphones.

Images