Abstract:
An apparatus and method for generating a muting signal. The apparatus includes an audio signal detector for remotely receiving an audio signal and a processor in communication with the detector. The processor is configured to compare the received audio signal with a predetermined audio signal generated by a device and generate a muting signal when at least a component of the received audio signal matches the predetermined audio signal.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to apparatuses and methods for muting an audio device upon the recognition of an audio input generated by another device. 
   2. Description of the Invention Background 
   The ring of a telephone, be it cordless, wired or cellular, invariably demands attention, and especially in situations when a call is expected, such as a business call in an office, an important call in a cell phone while driving, a family call while lying in a hospital bed, and so on. In many of these situations, a person may be listening to a program on the radio, a CD on a CD player, or watching television, or simply having a background sound from an audio device, when a telephone rings. It is often not convenient to reduce such “background” sound before the telephone is answered. When driving, in particular, muting the radio to answer a cell phone call, even when using a hands-free cell phone kit, may still be dangerous. 
   U.S. Pat. No. 5,404,391 discloses an incoming call alert system for cellular telephones without wired connection thereto. The alert system includes a transducer tuned to receive the voice channel frequency. 
   U.S. Pat. No. 5,678,200 discloses a device for controlling an accessory based on the detection of transmissions of appropriate input frequency exceeding a minimum threshold amplitude from a nearby cellular telephone. 
   SUMMARY 
   One embodiment of the invention provides an apparatus for generating a muting signal. The apparatus includes an audio signal detector for remotely receiving an audio signal and a processor in communication with the detector. The processor is configured to compare the received audio signal with a predetermined audio signal generated by a device, and generate a muting signal when at least a component of the received audio signal matches the predetermined audio signal. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying Figures, there are shown present embodiments of the invention wherein like reference numerals are employed to designate like parts and wherein: 
       FIG. 1  is a block diagram of an embodiment of the apparatus of the present invention; 
       FIG. 2  is an exemplary flowchart of one embodiment of a training session for the apparatus of  FIG. 1 ; 
       FIG. 3  is an exemplary flowchart which depicts one embodiment of the operation of the apparatus of  FIG. 1 ; 
       FIG. 4  is a schematic diagram of an embodiment of an audio device according to present invention, shown in the proximity of a telephone; 
       FIG. 5  is a block diagram of another embodiment of the apparatus of the present invention; and 
       FIG. 6  is an exemplary diagram of a template according to an embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings for the purpose of illustrating the invention and not for the purpose of limiting the same, it is to be understood that standard components or features that are within the purview of an artisan of ordinary skill and do not contribute to the understanding of the various embodiments of the invention are omitted from the drawings to enhance clarity. 
     FIG. 1  is a block diagram of an embodiment of an audio input recognizer and muter  20 , hereinafter “recognizer  20 ”, according to the present invention. A ring is the audible alert from a telephone or similar device  80  (shown in  FIG. 4 ) indicating that a telephone call signal is being received. The telephone device  80  may be a wireless terminal, i.e. cell phone, a cordless phone, a wired telephone apparatus, etc. However, the present invention is not limited to recognizing the ring of a telephone, but may also be configured to recognize other types of audible signals. 
   The recognizer  20  includes an audio detector  22 , such as a transducer or a microphone that receives an audio input. The recognizer  20  may also include an amplifier  24  that is connected to the detector  22 , for amplifying a detected audio signal from the detector  22 . The detected audio signal may then be transmitted to an analog/digital (A/D) converter  26  that digitizes the detected audio signal. The digitized detected audio signal may then be saved in a memory or storage device  28 , including an audio recording device, such as a CD, an audiocassette, hard disk or a logic block. The audio input may be a ring audio input from a telephone device  80 . The memory/storage device  28  may include digitized ring audio signals that are stored either during a training session or stored by the manufacturer of the recognizer  20 . 
   The recognizer  20  may also include a digital signal processor (DSP)  30 . The DSP  30  includes instructions for processing digital audio signals. The DSP  30  may include additional instructions and memory to increase the processing rate. Accordingly, the storage device  28  may be integral with or separate from the DSP  30 . The DSP  30  may be any type of suitable processor such as, for example, a microprocessor or a DSP integrated circuit chip or system. 
   The DSP  30  is operable to process digital audio signals. For example, in one embodiment, the DSP  30  compares a digitized detected audio signal to one or more pre-stored digitized ring audio signals that reside in the memory/storage device  28 . Processing, which may be continuous, may include, for example, filtering out environmental noise, performing correlations, transforms, or other mathematic functions for enhancing sensitivity to the pre-stored audio signal, extracting ring parameters for each ring audio input and creating a digital signature for a ring audio input. Processing may include any methods and associated circuitry that are known in digital signal processing, audio discriminator technologies and speech recognition, including speech recognition using neural network processing. An electronic audio discriminator for detecting breaking glass is, for example, described in U.S. Pat. No. 4,837,558, which is herein incorporated by reference in its entirety. A method and apparatus for training a system to assess the identity of a person through the audio characteristics of their voice applying neural network type processing is, for example, disclosed in U.S. Pat. No. 5,864,807, which is herein incorporated by reference in its entirety. 
   The DSP  30  may include software instructions or firmware to perform the functions described herein. Such software instructions may be implemented in any suitable computer language. 
   The DSP  30  recognizes an audio input as a ring audio input when the comparison between the digitized detected audio signal and a pre-stored digitized ring audio signal determines that the digitized audio signal contains a component that matches the pre-stored signal. In the event of a match, the DSP  30  transmits a muting signal to the mute circuitry  32  of an audio device  70 , shown in  FIG. 4 . The audio device  70  may be a car radio, a stereo system, a television, a CD player, a DVD player, or any such device that produces sound for listening and operates in the vicinity of the telephone  80 . The recognizer  20  may be integrally incorporated inside the audio device  70 , or it may be external to the audio device  70 , as shown in  FIG. 5 , in which case it may be connected to the audio device mute  32  through a jack  82  on the audio device  70 . The reference number  20 ′ is used hereinafter to indicate the recognizer embodiment of  FIG. 5 . 
   The recognizer  20  includes in the memory/storage device  28  a template  90  with N entries of digitized ring audio signals representing various ring tones, where N is an integer equal to or greater than 1. Some of the entries, for example in the range 1 to N 1  may be reserved and pre-programmed by the manufacturer into the template  90  of the recognizer  20 . Such entries may correspond to the most common ring tones for various brands of cell phones and wireless terminals, for example. Additionally, new entries, for example in the range (N 1 +1) to N may be stored in the recognizer  20  by the user, as illustrated in the flowchart of  FIG. 2 , during a training session. 
   At the start of a training session, the recognizer  20  is put in a ready mode to receive audio input. At action  40  the user causes the telephone  80  to ring in the proximity of the audio detector  22 , such as in an otherwise quiet environment to minimize ambient noise. At action  42 , the user may enter a storage number, for example a number in the range (N 1 +1) to N, to label the particular telephone ring and store it in an appropriate entry in the template  90  at action  44 . 
   The training procedure is now described in connection with the audio device  70  shown in  FIG. 4 . A training session is initiated by selecting a training mode to prepare the recognizer  20  to receive audio input and enter such input in digitized form into the template  90 . The training mode is selected, for example, by setting a training mode on/off switch  74  to the “on” position. The telephone  80  is made to ring in the vicinity of the detector  22 . A storage key  78 , such as, for example, a conventional push/pull radio key, or other conventional on/off button may be manipulated to assign a storage or labeling number to the entry. The storage operation may also be accomplished through a remote control unit  84  for the audio device  70 , and may include recording the audio input. 
   The flowchart of  FIG. 3  illustrates one method of operating the recognizer  20 . The operation is commenced with receipt of an audio input (action  50 ). A decision is then made to determine whether the detected audio signal is for the purpose of training or not based on the position of the training mode switch  74  (action  52 ). If the training mode switch  74  is “on”, the detected audio signal is processed for storage in the template  90  (action  54 ). If the training mode switch is “off”, the detected audio signal may be continuously processed for recognition by comparing its digitized form with the entries in the template  90  (action  56 ). A recognition decision is then made (action  58 ). If no match is found in the template  90 , then the digitized audio signal is cleared (action  60 ) and the sampling process begins again. If a match is found, the DSP  30  generates and transmits a signal to mute the audio device  70  (action  62 ). After the telephone conversation is over, the audio device can be returned to the un-muted position by operating manually, or through the remote control unit  84 , a muting on/off switch  76 , or automatically if the recognizer  20  is trained to recognize that a particular conversation is over or the phone is returned to an “on hook” position, by an audible voice command from the user, for example. 
   When the recognizer  20  is used in connection with a car radio or a car CD player, a driver or passenger in the car will not have to manually mute the radio in the event a cell phone rings in the car. 
   The recognizer  20  also may be used in connection with audio devices such as, for example, a television, a stereo system, a radio, a CD player, etc. in other environments, such as, for example, in an office room or cubicle or in a private room in a hospital. A person working in the office or a patient or visitor in the hospital room can answer the telephone without having to first mute or turn off the audio device either manually or by operating a remote control unit. 
   Whereas particular embodiments of the invention have been described herein for the purpose of illustrating the invention and not for the purpose of limiting the same, it will be appreciated by those of ordinary skill in the art that numerous variations of the details, materials and arrangement of parts may be made within the principle and scope of the invention without departing from the spirit invention. The preceding description, therefore, is not meant to limit the scope of the invention. Rather the scope of the invention is to be determined only by the appended claims and their equivalents.