Abstract:
A system and method are provided for improved speech synthesis, wherein text data is pre-processed according to updated grammar rules or a selected group of grammar rules. In one embodiment, the TTS system comprises a first memory adapted to store a text information database, a second memory adapted to store grammar rules, and a receiver adapted to receive update data regarding the grammar rules. The system also includes a TTS engine adapted to retrieve at least one text entry from the text information database, pre-process the at least one text entry by applying the updated grammar rules to the at least one text entry, and generate speech based at least in part on the least one pre-processed text entry.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention generally relates to a system and method for dynamically updating and using text-to-speech data. More specifically, the present invention relates to dynamically updating the grammar rules used to pre-process text information database entries to achieve improved output text-to-speech phonetics. 
         [0003]    2. Description of Related Art 
         [0004]    Systems incorporating text-to-speech engines or synthesizers coupled to a database of textual data are well known and continue to find an ever-increasing number of applications. For example, automobiles equipped with text-to-speech and speech-recognition capabilities simplify tasks that would otherwise require a driver to take away his/her attention from driving. The uses of text-to-speech output in a vehicle include, but are not limited to, controlling electronic systems aboard the vehicle, such as navigation systems, audio systems, etc. 
         [0005]    While the increasing applicability of text-to-speech (TTS) systems to electronic systems and devices, others have attempted to improve the output of text-to-speech phonetics, i.e., make the synthesized speech more natural or understandable for users. Toward this end, others have implemented a variety of fixed dictionaries. However, fixed dictionaries are necessarily large in order to handle a sufficiently large vocabulary. Moreover, a relatively high speed processor is needed to locate and retrieve entries from such large dictionaries with sufficient speed. 
         [0006]    Others have attempted to implement non-fixed dictionaries where certain textual data are pre-processed to achieve improved TTS output. Others have attempted to pre-process the textual data according to defined rules or via manual editing of textual database entries. Such approaches to pre-processing can be time-consuming and inefficient. Moreover, a given set of pre-processing or grammar rules for a particular application may be outdated or inappropriate for another application or scenario. 
         [0007]    Accordingly, it would be desirable to provide a system that can pre-process textual data with grammar rules that can be updated or adjusted for particular applications, user preferences, etc. Such a system would have the benefit of non-fixed dictionaries and updateable grammar rules with which to pre-process entries in the non-fixed dictionaries. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a system and method for improving the performance of text-to-speech (TTS) systems by dynamically updating the grammar rules used to pre-process textual entries in a text information database. 
         [0009]    In accordance with one aspect of the embodiments described herein, there is provided a system for pre-processing text for TTS generation, comprising a first memory adapted to store a text information database, a second memory adapted to store grammar rules, a receiver adapted to receive update data regarding the grammar rules and relay the received update data to the second memory, and an audio output device. The system further comprises a TTS engine operatively coupled to the first and second memories, the receiver, and the audio output device, wherein the TTS engine is adapted to: (a) retrieve at least one text entry from the text information database; (b) apply the updated grammar rules to the at least one text entry, and thereby pre-process the at least one text entry; (c) generate speech based at least in part on the least one pre-processed text entry; and (d) send the generated speech to the audio output device. 
         [0010]    In accordance with another aspect of the embodiments described herein, there is provided a system pre-processing text for TTS generation, comprising a memory adapted to store a text information database and grammar rules, a receiver to receive a request for the TTS generation, and an audio output device. The system further comprises a TTS engine operatively coupled to the memory, the receiver, and the audio output device, wherein the TTS engine is adapted to: (a) retrieve at least one text entry from the text information database according to the received request for the TTS generation; (b) retrieve a subset of rules from the grammar rules according to the received request; (c) apply the retrieved rules to the at least one text entry, and thereby pre-process the at least one text entry; (d) generate speech based at least in part on the at least one pre-processed text entry; and (e) send the generated speech to the audio output device. 
         [0011]    In accordance with another aspect of the embodiments described herein, there is provided a method for pre-processing text for a TTS engine according to grammar rules, comprising: (a) receiving update data regarding the grammar rules; (b) updating the grammar rules according to the received update data; (c) receiving a request for TTS generation; (d) retrieving at least one text entry from a text information database; (e) applying the updated grammar rules to the at least one text entry to pre-process the at least one text entry. The method can further comprise providing an audio output with TTS phonetics based at least in part on the at least one pre-processed text entry. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic diagram of one embodiment of a TTS system; 
           [0013]      FIG. 2  is a schematic diagram of another embodiment of a TTS system; 
           [0014]      FIG. 3   a  is a schematic diagram of an embodiment of a communication system pursuant to aspects of the invention; 
           [0015]      FIG. 3   b  is a schematic diagram of a navigation device in communication with a mobile unit according to an embodiment of the invention; 
           [0016]      FIG. 4  is a block diagram of an embodiment of a multi-packet dedicated broadcast data message; 
           [0017]      FIG. 5  is a diagram illustrating a subcarrier of a radio signal; and 
           [0018]      FIG. 6  is a schematic diagram illustrating an embodiment of a modified broadcast data stream. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]      FIGS. 1-7  illustrate several embodiments of a system and method for pre-processing text to improve the phonetic properties of the text before the text is further processed by a text-to-speech (TTS) engine or module. While the following description of the exemplary system is directed to an application of TTS engines for controlling vehicle navigation systems and other embedded systems, it should be appreciated that the system would apply equally well to other vehicle-related TTS applications, as well as other non-vehicle related TTS applications. 
         [0020]      FIG. 1  illustrates one exemplary embodiment of a TTS system  100 . In this embodiment, TTS system  100  includes, among other things, a memory  102 , a receiver  110 , a TTS module or engine  130 , and a set of grammar rules  120 . The memory  102  can comprise, for example, a hard disk drive or the like. The memory  102  stores a text information database  104  and a generated phonetic database  106 , explained in further detail below. The TTS engine  130  can comprise any conventional text-to-speech converter or reader known in the art. The grammar rules  120  generally comprise a set of rules used by the TTS engine  130  to generate a phonetic database  106 , which is in turn used to output TTS phonetics via an audio output device  140 , comprising speakers or the like, in response to an input request for TTS generation  110  received by the receiver  110 . The grammar rules  120  can be stored on the memory  102  or another memory that is separate from the memory  102 , such as cache, flash memory, or separate hard disk drive or the like. 
         [0021]    The receiver  110  is adapted to receive, among other things, requests for TTS generation. The receiver  110  relays the request to the TTS engine  130 , which in turn accesses and uses the grammar rules  120  to pre-process entries in the text information database  104  to generate a phonetic database  106 . The TTS engine  130  processes or converts the entries in the text information database  102  and then reads selected entries from the generated phonetic database  106  for the user. In the embodiment of  FIG. 1 , the TTS engine  130  stores the generated phonetic database  106  on the memory  102 . In another embodiment, the TTS engine  130  stores the generated phonetic database  106  or selected entries thereof on memory that is separate from the memory  102 . The output TTS phonetics resulting from the application of the grammar rules  120  to selected entries of the text information database  104  is played for the user via the audio output device  140 . 
         [0022]      FIG. 2  illustrates another embodiment of a TTS system  100  that includes, among other things, a memory  102 , a receiver  110 , a processor  112 , a TTS engine  130 , and a set of grammar rules  120 . The receiver  110  is adapted to receive, among other things, requests for TTS generation. The receiver  110  relays the request to the processor  112 , which in turn accesses and uses the grammar rules  120  to pre-process entries in the text information database  102  to generate a phonetic database  106 . The processor  112  converts entries in the text information database  104  and generates a phonetic database  106 . The TTS engine reads selected entries from the generated phonetic database  106  to output TTS phonetics for the user via the audio output device  140 . In the embodiment of  FIG. 2 , the processor  112  stores the generated phonetic database  106  on the memory  102 . In another embodiment, processor  112  stores the generated phonetic database  106  or selected entries from thereof on memory that is separate from the memory  102 , such as cache, flash memory, or separate hard disk drive or the like. 
         [0023]    The grammar rules  120  are used for automatically producing phonetics that can be saved for later use or used immediately for both TTS and voice recognition purposes. The grammar rules  120  can be stored in any suitable memory that is part of or operatively coupled to the TTS system  100 . The grammar rules  120  can be stored with or apart from the text information database  104  and/or the phonetic database  106 . The grammar rules  120 , regardless of where they are stored, make it possible for the TTS engine  130  or equivalent thereof to pre-process text to achieve better prosody of voice and comprehensibility by the user. The TTS engine  130  or separate processor  112  can be used to go through the text data  104  and generate the raw phonetics  106 , thereby allowing automated text manipulation for embedded or mobile TTS engines. 
         [0024]    In one embodiment, the grammar rules  120  comprise rules for removal, reformatting, and/or replacement of text based on word spelling (including abbreviations), word and sentence structure, or other formatting structures. The TTS engine  130  or processor  112  uses search algorithms and preprocesses (i.e., removes, reformats, or replaces) entries in the text database  104  to produce a partial or complete phonetic database  106 . The phonetic database  106  can be used by TTS and/or voice recognition engines. 
         [0025]    The removing technique involves searches for particular items and removal of the identified particular items from the database entries. The removing technique can be for specific words or phrases, as well for punctuation items, such as parenthesis. The purpose of removing words, phrases, or punctuation is to eliminate portions of text database entries that are inappropriate for the TTS engine or will likely cause confusion for the user. Examples of grammar rules  120  for removing symbols include: 
         [0000]    
       
         
               
               
             
           
               
                   
               
               
                   
                 Description 
               
               
                 Item 
                 (replace with a single space) 
               
               
                   
               
             
             
               
                 ... 
                 Triple periods 
               
               
                 !! 
                 Double exclaimation 
               
               
                 .. 
                 Double periods 
               
               
                 : 
                 Colon 
               
               
                 ? 
                 Question Mark 
               
               
                 
                   — 
                 
                 Underscore 
               
               
                 \ 
                 Backslash 
               
               
                 * 
                 Asterick 
               
               
                 ” 
                 Double quotes 
               
               
                 
                           
                 
                 Inverted question mark 
               
               
                 / 
                 Forward slash 
               
               
                   
               
             
          
         
       
     
         [0026]    The reformatting technique involves searches for particular items and changing all or part of the makeup of identified text database entries, such as providing alternative spellings for a mispronounced word or providing letter/word markups for optimum TTS generation. Depending on the particular application of the TTS system, grammar rules  120  appropriate for a given application, such as vehicle audio or music systems, are utilized. For example, in the context of audio systems, the grammar rules  120  can comprises an algorithm for reformatting “Live”, such that “Greatest Hits (Live)” becomes “Greatest Hits Live” (hard wound Lyve). In another example, the grammar rules  120  comprise a zero-to-O algorithm, such that “808 State” becomes “Eight Oh Eight State”. Examples of grammar rules  120  for reformatting classical music composer names can include: 
         [0000]    
       
         
               
               
             
           
               
                   
               
               
                 Composer Name 
                 Reformatted Composer Name 
               
               
                   
               
             
             
               
                 Alfred Schnittke 
                 AE L F R IX DD SH N IH TD K IX 
               
               
                 Antonin Dvorák 
                 AO N T AXR N Y IY N D V AO R ZH AO 
               
               
                   
                 KD 
               
               
                 Franz von Suppé 
                 F R AO N S F AH N S UW P EY 
               
               
                 Frédéric Chopin 
                 F R EH DX AX R IY KD SH OW P AE N 
               
               
                 Giacomo Puccini 
                 JH AO K AX M OW P UW CH IY N IY 
               
               
                 Johann Strauss I 
                 Y OW HH AO N S T R AW S DH IX F ER S 
               
               
                   
                 TD 
               
               
                 Pëtr Il&#39;ich Tchaikovsky 
                 P IY AXR T R IY L Y IY CH CH AY K AO 
               
               
                   
                 V S K IY 
               
               
                 Richard Wagner 
                 R IY SH AA R DD V AO G N AXR 
               
               
                   
               
             
          
         
       
     
         [0027]    The replace technique involves searches for particular items and replacing them with appropriate substitute items. This can involve replacing an abbreviation with its full word, or substituting letters or characters with appropriate substitutions. For example, the grammar rules  120  can comprises an algorithm for replacing “&amp;” with “and”, such that “Rock &amp; Roll” becomes “Rock and Roll”. In another example, the grammar rules  120  comprise an algorithm for replacing “feat.” with “featuring”, such that “Union (feat. Sting)” becomes “Union featuring Sting”. Examples of grammar rules  120  for replacing words and symbols include: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 Original 
                   
               
               
                   
                 Item 
                 Replacement Item 
               
               
                   
                   
               
             
             
               
                   
                 ft. 
                 featuring 
               
               
                   
                 jan 
                 January 
               
               
                   
                 feb 
                 February 
               
               
                   
                 arr. 
                 arranged by 
               
               
                   
                 conc. 
                 concerto 
               
               
                   
                 incl. 
                 incl. 
               
               
                   
                 mvt. 
                 movement 
               
               
                   
                 sym. 
                 symphony 
               
               
                   
                 no. 
                 number 
               
               
                   
                 # 
                 number 
               
               
                   
                 op. 
                 Opus 
               
               
                   
                 orch. 
                 orchestra 
               
               
                   
                   
               
             
          
         
       
     
         [0028]    Other examples of grammar rules  120  for audio or music systems include can include: 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
               
               
                 Grammar Rule 
                 Example 
                 Original 
                 Modified 
               
               
                   
               
             
             
               
                 For entries with one or two 
                 track 002 
                 track zero zero 
                 track 2 
               
               
                 zeros (e.g., 011 or 002), 
                   
                 two 
               
               
                 remove preceding zeros 
               
               
                 Change capital letters to be 
                 AC DC 
                 Ack DC 
                 A C D C 
               
               
                 read separately (mm. 2 
               
               
                 letters, max. 8 letters), and 
               
               
                 add spaces between letters 
               
               
                 When Live is surrounded 
                 Babylon by Bus 
                 Babylon by Bus 
                 Babylon by Bus 
               
               
                 by parenthesis or brackets, 
                 (Live) 
                 Live 
                 Lyve 
               
               
                 replace with Lyve 
               
               
                 Brackets or parentheses 
                 The Pretenders 
                 The Pretenders 
                 The Pretenders 
               
               
                 may have additional text. 
                 (Live in Las 
                 Live in Las Vegas 
                 Lyve in Las Vegas 
               
               
                 Keep all of text and only 
                 Vegas) 
               
               
                 make the spelling change 
               
               
                 Allow multiple entries by 
                 The Beatles (the 
                 The Beatles the 
                 The Beatles; The 
               
               
                 only saying what is outside 
                 White Album) 
                 White Album 
                 White Album, The 
               
               
                 or inside the parentheses 
                   
                   
                 Beatles the White 
               
               
                 or brackets 
                   
                   
                 Album 
               
               
                   
               
             
          
         
       
     
         [0029]    As explained above, particular grammar rules  120  can be selected and used for particular applications. While many of the examples of grammar rules  120  described herein are for audio or music systems, it will be understood that the grammar rules  120  generally can comprise rules for automatically producing phonetics that can be saved for later use or used immediately for both TTS and voice recognition purposes, and are not limited to any particular type of electronic system, such as embedded music, audio, or navigation systems. 
         [0030]    TTS data, including but not limited to grammar rules  120 , text information  104 , and generated text phonetics  106 , can be updated via any known approach. For example, in the embodiment of  FIGS. 1 and 2 , updated grammar rules  120  are transmitted to the TTS system  100  via satellite radio transmission, described in further detail below. The TTS data can be received by the receiver  110  or another receiver (not illustrated) operatively coupled to the memory device on which the grammar rules are stored. In another embodiment, the grammar rules are updated via interfacing a memory device (e.g., portable flash memory device, portable computing device, personal digital assistant, portable music player, etc.) with the TTS system  100 . 
         [0031]    The TTS system  100  typically comprises a receiver or is in communication with a receiver located on the vehicle that allows the TTS data (e.g., grammar rules  120 ) to be updated remotely. In one embodiment, the receiver supports the receipt of content from a remote location that is broadcast over a one-to-many communication network. One-to-many communication systems include systems that can send information from one source to a plurality of receivers, such as a broadcast network. Broadcast networks include television, radio, and satellite networks. For example, the grammar rules for TTS pre-processing can be updated by a remote broadcast signal such as via satellite radio broadcast service, as illustrated in  FIGS. 1 and 2 . The one-to-many communication network may comprise a broadcast center that is further in communication with one or more communication satellites  122  that relay a dedicated broadcast signal or a modified broadcast signal to the receiver located on the vehicle. For example, the broadcast center and the satellites  122  can be part of a satellite radio broadcasting system, such as XM Satellite Radio or the like. It will be understood that the dedicated broadcast signal and modified broadcast signal may be broadcast via any suitable information broadcast system (e.g., FM radio, AM radio, or the like), and is not limited to satellite radio broadcast systems. 
         [0032]    With reference to  FIG. 3   a,  there is provided an embodiment of a system for the exchange of information between a remote location  216  and a vehicle  201 . The remote location  216  is a server system for outputting vehicle broadcast data. The vehicle  201  includes a navigation device  208  and a mobile unit  202 . The navigation device  208  is an electronic system used to provide driving directions, display of messages to the vehicle operator, and audio playback of messages, radio broadcasts or other media. The navigation device  208  is operatively coupled to the mobile unit  202  and supports the receipt of content from the remote location  216  that is broadcast over a one-to-many communication network  200 . One-to-many communication systems include systems that can send information from one source to a plurality of receivers, such as a broadcast network. Broadcast networks include television, radio, and satellite networks. While the illustrative embodiments of the present invention include electronic systems that include a navigation component, it will be understood that the systems and methods described herein are applicable to any electronic system, such as an audio or media system, vehicle-embedded, portable, or otherwise. 
         [0033]    In one embodiment, data for the TTS data (e.g., grammar rules  120 ) is generated at the remote location  216  or an alternate location that is not within or near the vehicle  201 , The TTS data is broadcast from the remote location  216  over the one-to-many communication network  200  to the vehicle  201 . The mobile unit  202  receives the broadcasted message and can transmit the TTS data to the navigation device  208  for updating of the database of available grammar rules  120  and/or databases  104 ,  106 . With respect to the present illustrative embodiment, the grammar rules  120 , text information data  104 , and text phonetic data  106  are stored in memory  209  (see  FIG. 3   b ). It will be understood that such TTS data can also be stored in other memory devices on or associated with the vehicle  201 . 
         [0034]    The remote location  216  can include a remote server  218 , a remote transmitter  222 , and a remote memory  224 , that are each in communication with one another. The remote transmitter  222  communicates with the navigation device  208  and mobile unit  202  by way of the broadcast  200  communication network. The remote server  218  supports the routing of message content over the broadcast network  200 . The remote server  218  comprises an input unit, such as a keyboard, that allows the entry of updated grammar rules  120  or the like into memory  224 , and a processor unit that controls the communication over the one-to-many communication network  200 . 
         [0035]    The server  218  is in communication with the vehicle  201  over a one-to-many communication network  200 . In the present embodiment, the one-to-many communication network  200  comprises a broadcast center that is further in communication with one or more communication satellites  122  that relay the TTS data to a mobile unit  202  in the owner&#39;s vehicle  201 . In the present embodiment, the broadcast center and the satellites  122  are part of a satellite radio broadcasting system, such as XM Satellite Radio or the like. It will be understood that the TTS data can be broadcast via any suitable information broadcast system (e.g., FM radio, AM radio, or the like), and is not limited to the satellite radio broadcast system. In one embodiment, the mobile unit  202  relays the safety message to an onboard computer system, such as the vehicle&#39;s navigation system  208 , which in turn updates the database of TTS data, such as grammar rules  120 , text information data  104 , text phonetic data  106 , etc. 
         [0036]      FIG. 3   b  shows an expanded view of both the navigation device  208  and the mobile unit  202  contained on the vehicle  201 . The navigation device  208  may include an output unit  214 , a receiver unit  215 , an input unit  212 , a TTS engine  210 , a navigation memory unit  209 , a navigation processor unit  213 , and an RF transceiver unit  211  that are all in electrical communication with one another. The navigation memory unit  209  can store TTS data, such as grammar rules  120  and/or text information  104  and/or text phonetics  106 . Alternately, the TTS data or components thereof can be stored in memory that is not part of the navigation device  208 . The database(s) with TTS grammar rules  120  and/or text information  104  and/or text phonetics  106  can be updated in the vehicle by way of the input unit  212 , which can include a keyboard, a touch sensitive display, jog-dial control, etc. The TTS data can also be updated by way of information received through the receiver unit  215  and/or the RF transceiver unit  211 . 
         [0037]    The receiver unit  215  receives information from the remote location  216  and, in one embodiment, is in communication with the remote location by way of a one-to-many communication network  200  (see  FIG. 3   a ). The information received by the receiver  215  may be processed by the navigation processor unit  213 . The processed information may then be displayed by way of the output unit  214 , which includes at least one of a display and a speaker. In one embodiment, the receiver unit  215 , the navigation processor unit  213  and the output unit  214  are provided access to only subsets of the received broadcast information. 
         [0038]    In the embodiment shown in  FIG. 3   b,  the mobile unit  202  includes a wireless receiver  204 , a mobile unit processor  206 , and an RF transceiver unit  207  that are in communication with one another. The mobile unit  202  receives communication from the remote location  216  by way of the receiver  204 . In one embodiment, the navigation device  208  and mobile unit  202  are in communication with one another by way of RF transceiver units  207  and  211 . Both the navigation device  208  and the mobile unit  202  include RF transceiver units  211 ,  207 , which, in one embodiment, comply with the Bluetooth® wireless data communication format or the like. The RF transceiver units  211 ,  207  allow the navigation device  208  and the mobile unit  202  to communicate with one another. 
         [0039]    In embodiments that involve broadcasting the TTS data to affected vehicle owners, one or a few messages may be transmitted over a one-to-many communication network  200  that each comprise a plurality of one-to-one portions (shown in  FIG. 4 ), as opposed to transmitting a separate message for each vehicle. Each one-to-one portion will typically be applicable to a single affected vehicle and allows for the broadcast of targeted vehicle information over a one-to-many network  200  using less bandwidth than if each message was sent individually. When broadcasting a message over a one-to-many communication network  200 , all vehicles  201  within range of the network  200  may receive the message, however the message will be filtered by the mobile unit  202  of each vehicle  201  and only vehicles  201  specified in the one-to-one portions of the message will store the message for communication to the vehicle owner. In one embodiment, each one-to-one portion comprises a filter code section. The filter code section can comprise a given affected vehicle&#39;s vehicle identification number (VIN) or another suitable vehicle identifier known in the art. The vehicle identifier will typically comprise information relating to the vehicle type, model year, mileage, sales zone, etc., as explained in further detail in U.S. patent application Ser. No. 11/232,2001, filed Sep. 20, 2005, titled “Method and System for Broadcasting Data Messages to a Vehicle,” the content of which is incorporated in its entirety into this disclosure by reference. 
         [0040]    TTS updates can be received via a dedicated broadcast data stream. The dedicated data stream utilizes a specialized channel connection, such as the connection for transmitting traffic data described in U.S. patent application Ser. No. 11/266,879, filed Nov. 4, 2005, titled “Data Broadcast Method for Traffic Information,” the disclosure of which is incorporated in its entirety herein by reference. For example, the XM Satellite Radio signal uses 12.5 MHz of the S band: 2332.5 to 2345.0 MHz. XM provides portions of the available radio bandwidth to certain companies to utilize for specific applications. The transmission of messages over the negotiated bandwidth would be considered to be a dedicated data stream. In a preferred embodiment, only certain vehicles would be equipped to receive the dedicated broadcast signal or data set. The broadcast signal may comprise, by way of example only, a digital signal, FM signal, WiFi, cell, a satellite signal, a peer-to-peer network and the like. The TTS data can be embedded into the dedicated broadcast message received at the vehicle. 
         [0041]    To install new TTS data in the vehicle, the dedicated radio signal, containing one or a plurality of new or updated TTS phonetics and/or grammar rules, is transmitted to each on-board vehicle receiver unit  204 . With a dedicated signal, the in-vehicle hardware/software architecture would be able to accept this signal. In an exemplary embodiment, after the mobile unit receiver  204  receives a broadcast signal, the receiver  204  transmits the dedicated broadcast signal to the on-board vehicle processor  206 . The broadcast signal is then deciphered or filtered by the processor  206 . For example, the processor  206  filters out the TTS phonetics and/or grammar rules from the other portions of the dedicated broadcast signal (e.g., traffic information, the radio broadcast itself, etc.). The other portions of the broadcast signal are sent to the appropriate in-vehicle equipment (e.g., satellite radio receiver, navigation unit, etc.). 
         [0042]    In the present embodiment, the TTS data is sent by the processor  206  to the navigation device  208 , and is stored in the on-board memory  209  of the device. This updated TTS data, once stored in the on-board memory  209 , is then available to the TTS  210 . The on-board memory  209  may comprise any type of electronic storage device such as, but not limited to, a hard disk, flash memory, or the like. The on-board memory  209  may be separate from the navigation device  208  or integrated into it. The function of the on-board memory  209  can be dedicated to storing only TTS data or may comprise a multi-function storage capacity by also storing other content such as digital music and navigation-related information. 
         [0043]    The navigation device  208  preferably includes an electronic control unit (ECU) (not shown). The ECU processes the TTS data received by the receiver  204  so that the TTS data is stored in the appropriate memory, such as on-board memory  209 , memory  102 , etc., and can be used by the system. In the present embodiment, TTS data is transmitted to the vehicle and is stored in the on-board memory  209 . The ECU organizes and formats the data stored in the memory  209  into a format that is readable by the system, and in particular, so that the TTS engine  210  can read the data. 
         [0044]    In another embodiment, shown in  FIG. 5 , updates to the TTS data are transmitted to the vehicle via a modified broadcast signal. The TTS data may be transmitted in a subcarrier of the radio signal such as in a Radio Data System (RDS) signal shown in  FIG. 5 . The subcarrier is a portion of the channel range. The outlying portions of the radio frequency range are often used for additional transmission (i.e., text data). Song titles, radio station names, and stock information are commonly transferred today. It should be appreciated that the subcarrier may be used to carry TTS data in any radio signal (e.g., FM, AM, XM, Sirius, etc.). The illustrated embodiment involves transmitting text data pertaining to TTS phonetics by using the extra subcarrier range. 
         [0045]    An exemplary modified broadcast signal may be a standard radio audio signal  322  such that the radio signal is modified or combined  323  to also include TTS data  320 , as shown in  FIG. 6 . Combining multiple data streams into a single signal prior to broadcast is well known within the electronic arts. In the present embodiment, the modified broadcast signal updates the TTS stored in a navigation device  324 . The modified broadcast signal, similar to the dedicated broadcast signal shown in  FIG. 4 , can transmit signals through various channels (e.g., radio, satellite, WiFi, etc.). The receiver unit  304  of the vehicle receives the TTS data  320  along with the radio audio signal  322 . The receiver unit  304  separates the TTS data  320  from the radio audio signal  322  as is conventionally done with channel, category, and song information, and is known within the art. The TTS data  320  is sent to the navigation device  324  and stored in the memory  329 . The TTS data  320  can further comprise TTS data for other equipment in the vehicle, such as the air conditioning system, power windows, and so on. 
         [0046]    It should be appreciated that the above-described methods for dynamically updating and utilizing in-vehicle TTS data are for explanatory purposes only and that the invention is not limited thereby. Having thus described a preferred embodiment of a method and system for dynamically updating TTS data, it should be apparent to those skilled in the art that certain advantages of the described method and system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. It should also be apparent that many of the inventive concepts described above would be equally applicable to the use of other electronic systems, and are not limited to vehicle navigation systems.