Abstract:
A method of processing telephone sound is disclosed. Before the telephone sound is transmitted, the frequencies of high frequency consonants are lowered. If the recipient has severe hearing impairment, the frequencies of the high frequency consonants are lowered again.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention The present invention relates to a method of processing telephone signals. 
         [0002]    2. Description of the Related Art 
         [0003]    Hearing-impaired listeners who can hear sounds with the help of hearing aid devices often have difficulty hearing high-frequency sounds. Listeners with slight hearing impairment cannot hear sounds above 6,000 Hz, and those with severe hearing impairment cannot hear sounds above 2,000 Hz. For example, listeners with severe hearing impairment cannot hear sounds above 4,000 Hz even when the sounds are amplified to several times their original volume. Since consonant sounds are often above 4,000 Hz, the basic approach of hearing aid devices is to lower the frequency of the sound and to amplify it. In addition, hearing-impaired listeners can set some adjustable parameters according to their needs. The adjustable parameters are usually related to the frequency and the amplification of sounds to facilitate the processing of the sounds by the sound-processing program (software or firmware) inside the hearing aid devices. 
         [0004]    When a hearing-impaired listener speaks with other people face to face, common hearing aid devices are sufficient, since the devices lower or remove high-frequency sounds so that the hearing-impaired listener can hear the original high-frequency sounds. However, when the hearing-impaired listener speaks to others on a telephone, problems may arise because the phone first removes the high-frequency sounds before transmission. For example, the traditional telephone first removes frequencies above 4,000 Hz before transmission. Therefore, no sounds above 4,000 Hz are sent through telephones, and hearing-impaired listeners cannot easily identify the correct sounds on telephones as long as one side uses a traditional landline (or even 2G and 3G phones), particularly in the case of single-syllable words comprising high-frequency consonants and short vowel sounds (such as “sit”) and words in monosyllabic languages such as Chinese. 
         [0005]    When the hearing-impaired listener communicates with others on a network telephone, a problem is that some Internet phones remove frequencies above 4,000 Hz. 
         [0006]    Thus hearing-impaired listeners are in need of help in this regard. 
       SUMMARY OF THE INVENTION 
       [0007]    The main purpose of the present invention is to provide a method to help hearing-impaired listeners identify sounds more clearly when speaking on the phone. 
         [0008]    To achieve the above-mentioned purpose, in the present invention, when the caller sends a sound to the recipient, sounds with high-frequency consonants are first processed to lower the frequency and then sent out. 
         [0009]    When the recipient is a more severely hearing-impaired listener, sounds with high-frequency consonants are processed to lower the frequency. 
         [0010]    In the present invention, when the telephone sound is transmitted, sounds with high-frequency consonants will be processed to lower the frequency. Particularly, when any one of two sides (the two callers on the telephone) transmits a telephone sound with a bandwidth that is not high, such as 8,000 Hz or 4,000 Hz, then the processing of the present invention can facilitate the hearing-impaired listeners to hear the sounds. 
         [0011]    When the sound bandwidth in the phone transmission is higher, the sound cannot be processed for sending. However, when the sound is received, the sound may have to be processed, depending on the degree of hearing impairment of the recipient. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic diagram of the use environment and the electronic device hardware architecture diagram of the present invention. 
           [0013]      FIG. 2  is a schematic function diagram of the sound processing module of the present invention. 
           [0014]      FIG. 3  is a flowchart of the sound transmission segments in the sound processing module of the present invention. 
           [0015]      FIG. 4  is a flowchart of the sound-receiving segment in the sound processing module of the present invention. 
           [0016]      FIG. 5  is a schematic diagram of plural sound segments of the signals of sound input. 
           [0017]      FIG. 6  is a frequency schematic diagram of the sound input with low-frequency consonants and vowels. 
           [0018]      FIG. 7  is a schematic diagram of the sound transmission segments with low-frequency consonants and vowels. 
           [0019]      FIG. 8  is a frequency schematic diagram of the sound input with high-frequency consonants and vowels. 
           [0020]      FIG. 9  is a schematic diagram of the low-frequency process of the high-frequency consonants in the sound transmission segments. 
           [0021]      FIG. 10  is a schematic diagram of the sound transmission segments with high-frequency consonants and vowels. 
           [0022]      FIG. 11  is a schematic diagram of the low-frequency process of the high-frequency consonants in the sound-receiving segments. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0023]    To clarify the above and other purposes, features, and advantages of this invention, a specific embodiment of this invention is especially listed and described in detail with the attached figures as follows. 
         [0024]    Please refer to  FIG. 1 , which is a schematic diagram of the use environment and the electronic device hardware architecture diagram of the present invention. The caller calls the recipient through an electronic device  1   a,  and the recipient uses the electronic device phone  1   b  to make a call. The network  90  includes the Internet, telecommunications, wireless networks (such as 3G, 4G, and Wi-Fi), and so on. The electronic devices  1   a  and  1   b  can be mobile phones, smart phones, computers (Internet telephony), wireless radio, and telephones. The electronic device  1   a  can also be a home phone (but there is a need to install the audio processing module). The present invention is especially beneficial for a caller or a recipient who has some degree of hearing impairment. 
         [0025]    The electronic device la includes a processor  11 , a memory  12 , a microphone module  13 , a broadcast module  14 , and a sound signal communication module  15  (sending and receiving sound signals). The memory  12  stores a sound processing program  30  and an adjustable parameter  42 . The memory  12 , the microphone module  13 , the broadcast module  14 , and the sound signal communication module  15  are electrically connected to the processor  11 . 
         [0026]    It should be noted that, in this embodiment, the electronic devices  1   a  and  1   b  are electronic devices based on computer architecture, such as cell phones, smart phones, computers, and tablet computers. The processor  11  and the memory  12  in fact constitute the audio processing module  50 . The audio processing module  50  can be designed as hardware or firmware; it need not comprise a memory  12  with a processor  11 . In addition, the structure of the electronic device  1   b  is the same as that of the electronic device  1   a,  and therefore it will not be repeatedly labeled in  FIG. 1 . 
         [0027]    Please also refer to  FIG. 2  in order to understand the function of the audio processing module  50 . The sound input  20   a  of the caller is transmitted into the microphone module  13  to form the signal of the sound input  21   a,  and then the audio processing module  50  divides the signal of the sound input  21   a  into plural sound transmission segments  22   a,  executes the audio processing for a portion or all of the sound transmission segments  22   a,  and then transmits plural sound transmission segments  22   a  to the electronic device  1   b.    
         [0028]    The sound input  20   b  of the recipient (who uses the electronic device  1   b ) is processed through the electronic device  1   b,  forming the signal of the sound input  21   b.  The audio processing module  50  divides the signal of the sound input  21   b  into plural sound-receiving segments  22   b.  It is possible to execute audio processing on a portion or all of the sound-receiving segments  22   b  and then to play the sound-receiving segments  22   b  through the broadcast module  14 . 
         [0029]    Now please refer to  FIG. 3  and  FIG. 4 , which present a flowchart of the sound processing of the present invention, and to  FIG. 5  to  FIG. 11  for a detailed understanding of the invention. 
         [0030]    Step  301 : receiving the signals of sound input  21   a.    
         [0031]    Step  302 : dividing the signals of sound input  21   a  into plural sound transmission segments  22   a,  as shown in  FIG. 5 . The length of time for each sound segment is proposed to be 0.0001 to 0.1 seconds. In an experiment using an iPhone 4 as a hearing aid (based on the software produced and adopted in the iPhone 4 of the present invention), sound segments of 0.0001 to 0.1 second in length produced a good effect. 
         [0032]    Step  303 : Determining if the sound transmission segments  22   a  contain high frequency consonants. If yes, Step  304  is executed; if no, processing the next sound transmission segment  22   a.    
         [0033]    There are many methods to determine whether a sound is a high-frequency consonant or not. In the present invention, a sound is considered a high-frequency consonant when the sound transmission segments  22   a  have the following characteristics: 
         [0034]    Condition I: the energy of the sound transmission segment below 1,000 Hz is less than 50% of all of the energy of the sound transmission segment; and 
         [0035]    Condition II: the energy of the sound transmission segment above 2,000 Hz is larger than 30% of all of the energy of the sound transmission segment. 
         [0036]    A simpler way is that if a sound transmission segment above 2,500 Hz is greater than 50% of all of the energy of the sound transmission segment, it is considered a high-frequency consonant segment. 
         [0037]    Please refer to  FIG. 6 . The signals of the sound input  21   g  are, for example, “Pao” in Chinese or “Pin” in English, wherein the front section is the consonant and the back section is the vowel. The black mesh dots shown in  FIG. 6  represent the energy at a frequency, and how dense the black mesh spots are represents how high the energy is. The black lines represent that the energy is concentrated at a certain frequency. For example, when the sound transmission segment  22   j  (the low-frequency consonant) and the sound transmission segment  22   k  (the vowel) do not meet the conditions, then none of the sound transmission segments of the signals of the sound input  21   g  meet the conditions. The signals of the sound input  21   g  will be sent directly to the listener without being processed. After the signals of the sound input  21   g  are sent out, the signals of the sound input  21   g  above a certain bandwidth will be cut off due to the bandwidth regulation of the telephone transmission. For example, in a Skype™ voice call, sounds above 8,000 Hz will be cut off, and in a Skype™ video call, sounds above 4,000 Hz will be cut off. Please refer to  FIG. 7 , which presents an example in which the signals of the sound input  21   g  above 8,000 Hz are cut off. 
         [0038]    Please refer to  FIG. 8 ; when the signals of sound input  21   m  are, for example, “Zao” in Chinese or “see” in English, wherein the front section is the high-frequency consonant and the back section is the vowel, then if the sound transmission segment  22   n  meets the condition of a high-frequency consonant, Step  304  will be executed on the section of the high frequency consonants of the signals of the sound input  21   m.  However, Step  304  will not be executed on the vowels of the signals of the sound input  21   m.    
         [0039]    Step  304 : lowering the frequency of the sound transmission segments  22   a.  The processing of the signals of sound input  21   m  is presented as an example. Please refer to  FIG. 9 ; the high-frequency consonant in the front section is processed to lower its frequency (such as to 8 KHz or less). The frequency is lowered usually by compressing the frequency and/or shifting the frequency. For example, sounds from 6 KHz 12 KHz are compressed to 6 KHz-8 KHz, and sounds in the range of 0 KHz-6 KHz remain unchanged; or sounds from 8 KHz-12 KHz are compressed to the range of 8 KHz-10 KHz, and shifted to the range of 6 KHz-8 KHz. 
         [0040]    The high-frequency consonant is processed to lower the frequency. In Skype™, for example, the sounds of general calls over 8,000 Hz will be cut off (as is also true in current cellphone calls). However, since high frequency consonants have important sound energy at high frequencies, high frequency sounds are lowered in frequency to prevent sound information above 8,000 Hz from being cut off. In the video calls of Skype™, for example, since sounds above 4,000 Hz are cut off (as is also true with traditional phones), high frequencies should be reduced to below 4,000 Hz. “Zhi”, “chi” and “shi” in Chinese, for example, should be directly compressed from 2 KHz-8 KHz to 2 KHz-4 KHz. “Z”, “c” and “s” should be compressed from 6 KHz-16 KHz to 6 KHz-8 KHz, and then shifted to 2 KHz-4 KHz. Also, “j”, “q” and “x” should be compressed from 4 KHz-14 KHz to 4 KHz-6 KHz, and then shifted to 2 KHz-4 KHz. The studies of manufacturers and performances of electronic products for how to process the high-frequency consonants by lowering the frequency are different because of different languages. Since the point of the present invention is not to discuss various processes for lowering the frequency of high-frequency consonants, the processes will not be described in detail. 
         [0041]    After the signals of the sound input  21   m  are sent out, the signals of the sound input  21   m  above a certain bandwidth will be cut off due to the bandwidth regulation of telephone transmissions. Sounds above 8,000 Hz, for example, will be cut off. Please refer to  FIG. 10 . The point of this invention is that sounds above 8,000 Hz (or 4,000 Hz) will be cut off, but high-frequency consonants are lowered in frequency in the present invention. Therefore, the important sound information of high-frequency consonants is preserved. 
         [0042]    Please refer to the flowchart in  FIG. 4  and  FIG. 2 . The flowchart in  FIG. 4  explains the steps of how the audio processing module  50  processes the signals of the sound input  21   b.    
         [0043]    Step  401 : receiving signals of the sound input  21   b.    
         [0044]    Step  402 : determining if audio processing  42  is needed. If the adjustable parameter  42  does not exist, then the audio processing module  50  no longer processes the signals of sound input  21   b.  If the adjustable parameter  42  exists, the hearing-impaired level of the hearing-impaired listeners is mild, and the bandwidth of the signals of sound input  21   b  is wide enough, the processing will not be executed. For example, the frequency between 0 KHz-4 KHz is audible to the hearing-impaired listeners, but the frequency above 4 KHz is inaudible; if the signals of sound input  21   b  are between 0 KHz-4 KHz, the processing will not be executed; but if the signals of sound input  21   b  are between 0 KHz-8 KHz, Step  403  will be executed. 
         [0045]    The adjustable parameter  42  records the hearing information (for example, sounds above 4,000 HZ are difficult to hear) of the hearing-impaired listeners (including the elderly with hearing loss) or how the sound should be changed to improve audibility, such as amplification parameters, hearing parameters (like the hearing ability parameters of hearing-impaired listeners), or the frequency-variable parameter (such as the frequency-compressing parameter or frequency-shifting parameter). Because it is a well-known art to control the output of audio processing via the adjustable parameter  42  (hearing aid technology), then it will not be described in detail. It should be noted that the adjustable parameter  42  might also be an audiogram. The software program can perform calculations and determine how to change the sound based on the audiogram. 
         [0046]    Step  403 : dividing the signals of sound input  21   b  into plural sound-receiving segments  22   b.    
         [0047]    Step  404 : determining if the sound-receiving segments  22   b  contain high frequency consonants. In this step, Step  303  can be referred to. If yes, Step  405  is executed; if not, the next sound-receiving segment  22   b  is processed. 
         [0048]    Step  405 : Lowering the frequency of the sound-receiving segment  22   b.  For example, in  FIG. 10 , the signals of the sound input  21   b  have all been processed to below 8,000 Hz. However, since the sounds with high frequency consonants exist and the hearing-impaired listeners can only hear 0 KHz-4 KHz, the sound with high frequency consonants is processed to lower the frequency. The results of the processing are shown in  FIG. 11 . The part of the sound with a high-frequency consonant is processed to below 4 KHz. Basically, the vowels will not be processed (e.g., being reduced to below 4 KHz) in the invention. Because the energy of the vowels above  4  KHz is not large, the effect of the sound output will not be good if the frequency of vowels in the 4 KHz-8 KHz range is lowered or removed. 
         [0049]    It should be noted that, although a few exemplary embodiments of the present invention have been shown and described, the present invention is not limited to the described exemplary embodiments. Instead, it will be appreciated by those skilled in the art that changes may be made to these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents. Steps  301 - 304  and Steps  401 - 405  do not necessarily have to exist at the same time. As long as one of the steps is processed, it belongs to the feature of the present invention. When the bandwidth of the transmission sound of any one of both sides (the two users communicating with each other) is not high, Steps  301 - 304  are required. Steps  401 - 405  are applicable to processing for hearing-impaired listeners.