Abstract:
A device may include logic configured to detect information about a condition of a speaker in a communications device. The logic may process the information, load equalization logic based on the processed information, and may apply the equalization logic to an input signal of the speaker when the information indicates that a frequency response for the speaker should be changed.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Technical Field of the Invention  
         [0002]     Implementations described herein relate generally to audio output devices, and more particularly, to speakers used in handheld devices.  
         [0003]     2. Description of Related Art  
         [0004]     Devices, such as mobile communication devices, may be used by individuals in a variety of settings due to the portability of these devices. For example, an individual may receive a call while in his/her automobile and the individual may continue with the call while exiting the vehicle and walking down a noisy city street. When this individual received the call, the individual may have been in an environment with low background noise, e.g. the passenger compartment of a stationary automobile; however, as the call progressed, the individual may have entered a high background noise environment, e.g. the crowded city street.  
         [0005]     An individual may have to make adjustments to a mobile communications device while engaged in a call if background noise levels change, e.g., goes from a low level to a high level, or vice versa. For example, an individual may increase the volume for a speaker in order to hear what the party on the other end of a call is saying when the individual is engaged in a call in a high background noise environment. An individual may also force a portion of a mobile device housing a speaker against his/her ear with greater force when engaged in a call in a high background noise environment. When an individual forces a portion of a mobile device against his/her ear, the acoustic characteristics of the speaker may change. For example, forcing an ear piece on a mobile device against one&#39;s ear may cause low frequency portions of a frequency response for a speaker located in the ear piece to change. As a result, sound coming out of the speaker may take on undesirable characteristics, e.g., a low frequency portion of the speaker output may have an amplitude that is higher than desired, resulting in too much bass in the speaker output.  
         [0006]     An individual may not be satisfied with the sound quality of mobile communications devices when the frequency response of a speaker causes portions of a spectrum, such as low frequency portions of the spectrum, for the speaker to be unexpectedly amplified or attenuated in response to actions performed by the individual during a call.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     According to one aspect, a device is provided. The device may include logic configured to detect information about a condition of a speaker in a communications device, process the information, load equalization logic based on the processed information, and apply the equalization logic to an input signal of the speaker when the information indicates that a frequency response for the speaker should be changed.  
         [0008]     Implementations of the device may include detection logic comprising one of acoustic feedback logic, volume setting logic, pressure feedback logic, or impedance feedback logic. The device may further include detection logic comprising logic to determine a volume setting, logic to detect an acoustic signal related to a background noise level, logic to detect a pressure exerted on the communications device proximate to the speaker, or logic to measure an input impedance of the speaker.  
         [0009]     The device may include equalization logic comprising an equalization file containing machine-readable instructions configured to modify the frequency response of the speaker. The device may include logic configured to detect a user input configured to change the condition of the speaker.  
         [0010]     According to another aspect, a method is provided. The method may include monitoring a speaker in a communications device during a communications session; determining whether a portion of a frequency response for the speaker is within a determined limit; retrieving an equalization signal from a memory in response to the determining; and applying the equalization signal to an input signal of the speaker to modify the portion of the frequency response when the portion of the frequency response is outside the determined limit.  
         [0011]     In the method, the determining may further comprise determining if an amplitude for the portion of the frequency response is within or outside the determined limit, or determining if a spectral characteristic of the portion of the frequency response is within or outside the determined limit. The determining may further comprise establishing a lower limit or an upper limit for a frequency band, associating the portion of the frequency response with a range of frequencies above the lower limit or below the upper limit, and determining if frequencies within the portion of the frequency response are within or outside the determined limit.  
         [0012]     In the method, the monitoring may further comprise monitoring a volume setting for the speaker, monitoring an impedance of the speaker, monitoring a pressure proximate to the speaker, monitoring a background noise level or an output of the speaker using a microphone proximate to the speaker, and detecting information about a relationship between a user and the communication device. The monitoring may further comprise detecting information about a first relationship between a user and the communication device, where the first relationship has a first frequency response therewith, detecting information about a second relationship between the user and the communication device, where the second relationship has a second frequency response that differs from the first frequency response, and providing the information about the first relationship or the second relationship to the determining, and the determining may further comprise determining whether the first frequency response or the second frequency response is within or outside the determined limit. The method may further comprise monitoring the speaker after applying the equalization signal to determine if the frequency response is within the determined limit.  
         [0013]     According to yet another aspect, a mobile communications terminal is provided. The mobile communications terminal may include a housing comprising a speaker to provide audio signals to a user, a keypad to receive inputs from the user, a microphone to receive speech from the user, and processing logic. The processing logic may be configured to receive an input from the speaker, keypad, microphone, housing, or another device; determine, based on the input, whether a frequency response for the speaker should be changed; and apply an equalization signal to the speaker when the frequency response should be changed, the equalization signal configured to alter the frequency response of the speaker. The processing logic may receive an impedance value on behalf of the speaker, a user input from the keypad, a background noise level value from the microphone, a speaker sound level value from the microphone, or a pressure value from the housing or the other device.  
         [0014]     According to yet another aspect, a computer readable medium that stores instructions executable by a processing device is provided. The computer readable medium may comprise instructions to obtain information about a speaker in a communications device; instructions to determine when a frequency response for the speaker is outside a preferred range; instructions to identify an equalization instruction configured to produce an adjusted frequency response that is within the preferred range when applied to an input signal of the speaker that is present when the frequency response is outside the preferred range; instructions to apply the identified equalization instruction to the input signal to produce an equalized input signal; and instructions to determine whether the frequency response is outside the preferred range when the equalized input signal is applied.  
         [0015]     According to still another aspect, a mobile communications terminal employing adaptive speaker equalization is provided. The mobile communications terminal may comprise means for receiving information about a speaker operating in the terminal during a communications session; means for determining whether a frequency response for the speaker is within a determined range; means for loading an equalization file when the frequency response is outside the determined range; and means for applying information in the equalization file to an input signal of the speaker to bring the frequency response within the determined range. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings,  
         [0017]      FIG. 1  is a diagram of an exemplary implementation of a mobile terminal consistent with the principles of the invention;  
         [0018]      FIG. 2  illustrates an exemplary functional diagram of a mobile terminal consistent with the principles of the invention;  
         [0019]      FIG. 3  illustrates an exemplary functional diagram of the processing logic of  FIG. 2  consistent with the principles of the invention;  
         [0020]      FIG. 4  illustrates an exemplary data structure consistent with the principles of the invention;  
         [0021]     FIGS.  5 A-D illustrate exemplary relationships between a mobile terminal and a user consistent with the principles of the invention;  
         [0022]     FIGS.  6 A-C illustrate exemplary frequency response curves that can be used with exemplary speaker implementations consistent with the principles of the invention; and  
         [0023]      FIG. 7  is a flowchart of an exemplary method consistent with the principles of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention.  
         [0025]     Implementations of the invention can be used to improve the characteristics of sound coming from a speaker in a device, such as a communications device. Implementations of the invention may adapt characteristics of the speaker output based on user selections or based on the detection of parameters, such as background noise levels. Implementations may alter portions of a frequency response curve for the speaker based on the user selections or detected background noise levels. For example, an implementation may increase or decrease the amplitude of certain frequencies within a frequency response curve based on a state of the device.  
         [0026]     Exemplary implementations of the invention will be described in the context of a mobile communications terminal. It should be understood that a mobile communication terminal is an example of a device that can employ adaptive speaker equalization consistent with the principles of the invention and should not be construed as limiting the types or sizes of devices or applications that can use implementations of adaptive speaker equalization described herein.  
       Exemplary Mobile Terminal  
       [0027]      FIG. 1  is a diagram of an exemplary implementation of a mobile terminal consistent with the principles of the invention. Mobile terminal  100  (hereinafter terminal  100 ) may be a mobile communication device. As used herein, a “mobile communication device” and/or “mobile terminal” may include a radiotelephone; a personal communications system (PCS) terminal that may combine a cellular radiotelephone with data processing, a facsimile, and data communications capabilities; a personal digital assistant (PDA) that can include a radiotelephone, pager, Internet/intranet access, web browser, organizer, calendar, and/or global positioning system (GPS) receiver; and a laptop and/or palmtop receiver or other appliance that includes a radiotelephone transceiver.  
         [0028]     Terminal  100  may include housing  101 , keypad  110 , control keys  120 , speaker  130 , display  140 , and microphones  150  and  150 A. Housing  101  may include a structure configured to hold devices and components used in terminal  100 . For example, housing  101  may be formed from plastic and configured to support keys  112 A-L (collectively keys  112 ), control keys  120 , speaker  130 , display  140  and microphone  150  or  150 A. Housing  101  may have a first side  102 , a second side  103 , a third side  104 , a fourth side  105 , upper surface  106 , and a lower surface (not shown). In one implementation, first side  102  may correspond to a right side of terminal  100 , second side  103  may correspond to a lower side of terminal  100 , third side  104  may correspond to a left side of terminal  100  and fourth side  105  may correspond to an upper side of terminal  100 . Upper surface  106  may support speaker  130 , microphones  150  and  150 A and other components of terminal  100 .  
         [0029]     Keypad  110  may include devices, such as keys  112 A-L, that can be used to enter information into terminal  100 . Keys  112  may be used in a keypad (as shown in  FIG. 1 ), in a keyboard, or in some other arrangement of keys. Implementations of keys  112  may have key information associated therewith, such as numbers, letters, symbols, etc. A user may interact with keys  112  to input key information into terminal  100 . For example, a user may operate keys  112  to enter digits, commands, and/or text, into terminal  100 .  
         [0030]     Control keys  120  may include buttons that permit a user to interact with terminal  100  to cause terminal  100  to perform an action, such as to display a text message via display  140 , raise or lower a volume setting for speaker  130 , etc. Speaker  130  may include a device that provides audible information to a user of terminal  100 . Speaker  130  may be located in an upper portion of terminal  100  proximate to fourth side  105  and may function as an ear piece when a user is engaged in a communication session using terminal  100 .  
         [0031]     Display  140  may include a device that provides visual information to a user. For example, display  140  may provide information regarding incoming or outgoing calls, text messages, games, phone books, the current date/time, volume settings, etc., to a user of terminal  100 . Microphones  150  and/or  150 A may, respectively, include a device that converts speech or other acoustic signals into electrical signals for use by terminal  100 . Microphone  150  may be located proximate to a lower side of terminal  100  (e.g., proximate to second side  103 ) and may be configured to convert spoken words or phrases into electrical signals for use by terminal  100 . Microphone  150 A may be located proximate to speaker  130  and may be configured to receive acoustic signals proximate to a user&#39;s ear while the user is engaged in a communications session using terminal  100 . For example, microphone  150 A may be configured to receive background noise and/or sound coming from speaker  130 .  
       Exemplary Functional Diagram  
       [0032]      FIG. 2  illustrates an exemplary functional diagram of a mobile terminal consistent with the principles of the invention. As shown in  FIG. 2 , terminal  100  may include processing logic  210 , storage logic  220 , user interface  230 , communication interface  240 , and antenna assembly  250 . Processing logic  210  may include a processor, microprocessor, an application specific integrated circuit (ASIC), field programmable gate array (FPGA), or the like. Processing logic  210  may include data structures or software programs to control operation of terminal  100  and its components. Storage logic  220  may include a random access memory (RAM), a read only memory (ROM), and/or another type of memory to store data and instructions that may be used by processing logic  210 .  
         [0033]     User interface  230  may include mechanisms for inputting information to terminal  100  and/or for outputting information from terminal  100 . Examples of input and output mechanisms might include a speaker (e.g., speaker  130 ) to receive electrical signals and output audio signals, a microphone (e.g., microphone  150  or  150 A) to receive audio signals and output electrical signals, buttons (e.g., control keys  120  and/or keys  112 ) to permit data and control commands to be input into terminal  100 , a display (e.g., display  140 ) to output visual information, and/or a vibrator to cause terminal  100  to vibrate.  
         [0034]     Communication interface  240  may include, for example, a transmitter that may convert base band signals from processing logic  210  to radio frequency (RF) signals and/or a receiver that may convert RF signals to base band signals. Alternatively, communication interface  240  may include a transceiver to perform functions of both a transmitter and a receiver. Communication interface  240  may connect to antenna assembly  250  for transmission and reception of the RF signals. Antenna assembly  250  may include one or more antennas to transmit and receive RF signals over the air. Antenna assembly  250  may receive RF signals from communication interface  240  and transmit them over the air and receive RF signals over the air and provide them to communication interface  240 .  
         [0035]     As will be described in detail below, terminal  100 , consistent with the principles of the invention, may perform certain operations relating to adaptively equalizing the response of a speaker. Terminal  100  may perform these operations in response to processing logic  210  executing software instructions of a speaker equalization application contained in a computer-readable medium, such as storage  220 . A computer-readable medium may be defined as a physical or logical memory device and/or carrier wave.  
         [0036]     The software instructions may be read into storage logic  220  from another computer-readable medium or from another device via communication interface  240 . The software instructions contained in storage  220  may cause processing logic  210  to perform processes that will be described later. Alternatively, hardwired circuitry may be used in place of or in combination with software instructions to implement processes consistent with the principles of the invention. Thus, implementations consistent with the principles of the invention are not limited to any specific combination of hardware circuitry and software.  
       Exemplary Processing Logic Functional Diagram  
       [0037]      FIG. 3  illustrates an exemplary functional diagram of the processing logic of  FIG. 2  consistent with the principles of the invention. Processing logic  210  may include control logic  310 , sensing logic  320 , retrieving logic  330 , application logic  340  and interface logic  350 .  
         [0038]     Control logic  310  may include logic that controls the operation of terminal  100  and processes involved in operating terminal  100 . Control logic  310  may be implemented in hardware or software based logic.  
         [0039]     Sensing logic  320  may include logic used to obtain information on behalf of terminal  100 . For example, an implementation of sensing logic  320  may include acoustic feedback logic  322 , volume setting logic  324 , pressure feedback logic  326 , and impedance feedback logic  328 . Acoustic feedback logic  322  may receive an input from microphone  150 A. For example, microphone  150 A may provide an electrical signal that is proportional to a background noise level proximate to speaker  130  and a user&#39;s ear. Acoustic feedback logic  322  may receive the signal from microphone  150 A and may provide the signal to control logic  310  for processing.  
         [0040]     Volume setting logic  324  may include logic to establish a volume setting for speaker  130 . For example, a user may depress a control key  120  to increase or decrease a volume setting for speaker  130 . Volume setting logic  324  may receive a signal from the control key  120  and may raise or lower a volume setting for speaker  130  alone or in conjunction with control logic  310 . Volume setting logic  324  may be configured to receive signals on behalf of a user or may be configured to automatically adjust volume settings for speaker  130  based on signals received from other components operating in terminal  100 , such as acoustic feedback logic  322 , pressure feedback logic  326 , etc.  
         [0041]     Pressure feedback logic  326  may include logic to measure a force exerted on a portion of terminal  100 . For example, an implementation of pressure feedback logic  326  may include a strain gauge or pressure sensor that generates an output based on a force proximate to the pressure sensor and/or speaker  130 . Assume that a user presses terminal  100  against his/her ear with a first force when speaking in an empty function hall. Further assume that the user presses terminal  100  against his/her ear with a second force that is greater than the first force when the function hall is full of people. Pressure feedback logic  326  may sense the first pressure or the second pressure and may change characteristics of speaker  130  based on an output of pressure feedback logic  326 . For example, a volume setting of speaker  130  may be increased and/or a frequency response for speaker  130  may be changed in response to the second pressure since the second pressure may be associated with a user that is pressing an ear piece against his/her ear in order to hear sound coming from speaker  130  when using terminal  100  in a high background noise environments.  
         [0042]     Impedance feedback logic  328  may include logic that monitors an acoustic, mechanical, or electrical impedance of a component in terminal  100 , such as an impedance of speaker  130 . For example, speaker  130  may have a first impedance when the user applies the first force to terminal  100  while using terminal  100  in the empty function hall, and speaker  130  may have a second impedance when the user applies the second force to terminal  100  while using terminal  100  in the crowded function hall. Impedance feedback logic  328  may measure the first impedance or the second impedance and may provide a signal to control logic  310  that is used to change one or more characteristics of speaker  130 . For example, control logic  310  may retrieve an equalization file or may generate an equalization file for use in driving speaker  130  in a manner that produces a desired frequency response for speaker  130  based on a configuration of terminal  100 .  
         [0043]     Retrieving logic  330  may include logic to retrieve one or more equalization files  332  that can be used to modify a frequency response for speaker  130  based on usage configurations of terminal  100 . Retrieving logic  330  may operate with one or more equalization files  332 , such as first equalization file  334 , second equalization file  336 , and nth equalization file  338 . Equalization files  332  may include equalization instructions that are configured to change a frequency response for speaker  130  when applied to an input of speaker  130 .  
         [0044]     Assume that first equalization file  334  includes instructions to modify the frequency response for speaker  130  when a user is pressing terminal  100  against his/her ear with light pressure, such as would be used when the user is engaged in a call in a quiet room, and second equalization file  336  includes instructions that can be used to modify the frequency response of speaker  130  when the user is firmly pressing terminal  100  against his/her ear, such as when the user is engaged in a call in a noisy room. Further assume that nth equalization file  338  may be used to modify a frequency response of speaker  130  when the user is using terminal  100  in another operating environment, such as operating terminal  100  outdoors when a strong wind is blowing and creating wind noise proximate to speaker  130  and the user&#39;s ear.  
         [0045]     Implementations of equalization files  332  may be of a certain format, such as an audio parameter file format that may be identified using a file designation, or extension, such as “.asp”. Audio parameter files may include machine-readable instructions configured to change a frequency response for speaker  130 . For example, information in an audio parameter file may be applied to an input signal of speaker  130 . The combined input signal and audio parameter file information may operate to produce a desired frequency response at an output of speaker  130 .  
         [0046]     Application logic  340  may include logic that applies equalization files  332  to speaker  130  in cooperation with interface logic  350 . For example, application logic  340  may convert information in equalization files  332  into a digital form that can be applied to digitized acoustic signals intended for speaker  130 . In one implementation, terminal  100  may receive digitized acoustic signals via a wireless link. Processing logic  210  may receive these digitized acoustic signals from communication interface  240  and may apply one or more equalization files  332  to the digitized acoustic signals via application logic  340  to produce an equalized speaker input signal. Application logic  240  may provide the equalized speaker input signal to interface logic  350 . Interface logic  350  may include logic to provide digitized acoustic signals and/or equalized speaker input signals to speaker  130  to produce sound having characteristics that are appealing to a user of terminal  100 .  
       Exemplary Data Structure  
       [0047]      FIG. 4  illustrates an exemplary data structure consistent with the principles of the invention. Data structure  400  may include a computer-readable medium that can be used to store information in a machine-readable format. In an exemplary implementation, data structure  400  may be used to store information that is used to modify a frequency response for speaker  130  based on an operating characteristics of terminal  100  or based on a user input.  
         [0048]     Data structure  400  may include information arranged in fields, such as volume setting field  410 , equalization file field  420 , in use field  430 , and other field  440 . Information in data structure  400  may be arranged in a row and column format to facilitate interpretation by a user of terminal  100 . Entries  402 - 406  may be used to identify information associated with volume setting field  410 , equalization file field  420 , in use field  430 , and other field  440 .  
         [0049]     Volume setting field  410  may include information that represents a volume setting that can be used with terminal  100 . For example, terminal  100  may be configured to operate with volume settings having a range from zero to ten, with zero being the lowest volume setting and ten being a highest volume setting. Volume setting field  410  may include a single volume setting for an entry, such as 0, 1, 5, etc., or may include ranges of volume settings for respective entries in data structure  400 , such as 0-3 for entry  402 , 4-7 for entry  404 , or 8-10 for entry  406 .  
         [0050]     Equalization file field  420  may include information that can be used to identify one or more equalization files  332  that can be used to modify a frequency response of speaker  130 . In one implementation, equalization files  334 ,  336 ,  338  may each be identified with a range of volume settings. Equalization files  334 - 338  may have identifiers, such as numerical identifiers or alphanumeric identifiers, associated there with. For example, an equalization file that is used for a volume setting of 0-3 may be identified as equalization file  001 . Equalization file  001  may correspond to first equalization file  334  in one implementation.  
         [0051]     In use field  430  may include information that identifies whether an equalization file identified by equalization file field  420  is being used by terminal  100 . For example, in use field  430  may include NO for entries  402  and  406  to indicate that the respective equalization files (i.e., equalization files having identifiers of  001  and  003 , respectively) for those entries are not currently in use by terminal  100 . In contrast, in use filed  430  for entry  404  may include YES to indicate that equalization file  002  is in use by terminal  100 .  
       Exemplary Usage Configuration  
       [0052]     FIGS.  5 A-D illustrate exemplary relationships between a mobile terminal and a user consistent with the principles of the invention.  FIG. 5A  illustrates an exemplary relationship between a user and mobile terminal  100  when the user is engaged in a communication session using terminal  100 . For example,  FIG. 5A  shows an outline of terminal  100  in relationship to a user&#39;s ear  510 . In the exemplary configuration of  FIG. 5A , speaker  130  may be arranged substantially in line with ear canal  520  so that sound from speaker  130  is conveyed into ear canal  520  in an unimpeded manner.  
         [0053]      FIG. 5B  illustrates a side view of the relationship of  FIG. 5A .  FIG. 5B  may represent a configuration that is employed by a user when using terminal  100  in environments with low background noise, such as an empty room. Terminal  100  may be configured to provide sound from speaker  130  to ear canal  520  with a first frequency response that is selected to make sound quality satisfactory to a user. For example, the first frequency response may be selected so that bass, mid range, and high range frequencies are balanced in a way that allows the user to understand a party on the other end of a call. When a user employs the relationship of  FIG. 5B , terminal  100  may contact the user&#39;s ear  510  at location  530 .  
         [0054]     Implementations of terminal  100  may be configured with a port  560  (also referred to as a vent) to allow pressure on a back side of speaker  130  (e.g. the portion of speaker facing an interior portion of terminal  100 ) to be equalized with a pressure on a front side of speaker  130  (e.g., the portion of speaker  130  that faces ear canal  520  in  FIG. 5B ).  FIG. 5D  illustrates port  560 , speaker  130 , and an interior volume  550  of terminal  100  in more detail. Terminal  100  may be configured to provide acoustic signals to ear canal  520  according to a determined frequency response when the pressure on the backside of speaker  130  is substantially equal to a pressure on a front side of speaker  130 , such as the relationship of  FIG. 5B . A frequency response used for speaker  130  in the relationship of  FIG. 5B  may be configured to account for leakage (i.e., acoustic signals passing through port  560  and entering ear canal  520  via the gap between ear  510  and the top of terminal  100  shown in  FIG. 5B .  
         [0055]      FIG. 5C  illustrates an alternative relationship between a user and terminal  100 . The relationship of  FIG. 5C  may represent a situation where a user is pressing terminal  100  against his/her ear with greater force as compared to a force between terminal  100  an a user&#39;s ear in  FIG. 5B . A user may employ the relationship of  FIG. 5C  when engaged in a communication session in an environment with high background noise. The user may press terminal  100  against his/her ear in order to increase the signal-to-noise ratio (i.e., increase the volume of the desired signal coming out of speaker  130  with respect to a background noise level). When the user employs the relationship of  FIG. 5C , an upper portion of terminal  100  may contact ear  510  at location  540  while a lower portion of terminal  100  contacts ear  510  at location  530 . A seal may be formed between terminal  100  and a user&#39;s ear  510  when terminal  100  contacts the user&#39;s ear  510  at location  540  and  530 . The seal may cause a pressure on a front side of speaker  130  to increase with respect to a pressure on a back side of speaker  130 , thus changing the frequency response of speaker  130 . The relationship of  FIG. 5C  may also reduce and/or eliminate leakage from port  560  to ear canal  520  around the upper portion of terminal  100 . Reducing and/or eliminating leakage reaching ear canal  520  may further change the characteristics of sound entering ear canal  520  in  FIG. 5C .  
       Exemplary Speaker Characteristics  
       [0056]     FIGS.  6 A-C illustrate exemplary frequency response curves that can be used with exemplary speaker implementations consistent with the principles of the invention.  FIG. 6A  illustrates an exemplary frequency response curve  610  for speaker  130 . Frequency response curve  610  may be represented along a y-axis  620  that represents a sound pressure level (SPL) that can have units of decibels (dB). Frequency response curve  610  may also be represented along an x-axis that represents a frequency that may have units of Hertz (Hz). Frequency response curve  610  may represent the output characteristics of speaker  130  for a particular configuration. For example, frequency response  610  may represent an output of speaker  130  for the relationship illustrated in  FIG. 5B .  
         [0057]      FIG. 6B  illustrates a second exemplary frequency response curve  640  that may represent output characteristics of speaker  130  for a second configuration. For example, frequency response curve  640  may occur when a user presses terminal  100  against his/her ear with sufficient force so as to form a seal (e.g., the relationship illustrated in  FIG. 5C ). When frequency response curve  640  is present, a user may perceive sound coming from speaker  130  as having too much bass. As a result, sound coming from speaker  130  may have a boomy quality, thus making it difficult for the user to understand what a party on the other end of a call is saying.  
         [0058]     Implementations of the invention may provide modified equalization signals to speaker  130  to produce desired frequency response curves for substantially any relationship between a user and terminal  100 . For example, first equalization file  334  may be used to produce frequency response curve  610  for the relationship shown in  FIG. 5B . If a user presses the phone to his/her ear as shown in  FIG. 5C , first equalization file  334  may produce frequency response curve  640  if applied to speaker  130  when the relationship of  FIG. 5C  is present. An implementation of the invention may apply, for example, second equalization file  336  to speaker  130  when the relationship of  FIG. 5C  is present so that frequency response curve  610  is achieved.  
         [0059]      FIG. 6C  illustrates a relationship between frequency response curves  610  and  640 . Implementations may provide equalization signals that take into account a relationship between a user and terminal  100 . For example, implementations may determine a frequency band  670  over which corrective equalization may be made. Frequency band  670  may have a lower range  650  that may represent a lowest frequency over which a frequency response correction may be made. Frequency band  670  may further include an upper range  660  that may represent a highest frequency over which a frequency response correction may be made. In one implementation, upper range  660  may correspond with a cross over point  665 , i.e. a frequency at which frequency response curves  610  and  640  intersect. Implementations may further determine an amplitude difference  680  between a desired frequency response curve (e.g., frequency response curve  610 ) and an undesirable frequency response curve that is caused by a relationship between a user and terminal  100  (e.g., frequency response curve  640 ). Amplitude difference  680  may be implemented as an average across frequency band  670  or may be done on a frequency by frequency basis. For example, amplitude difference  680  may be performed for each frequency making up band  670 , e.g., frequencies at 100 Hz, 101 Hz, etc.  
         [0060]     Second equalization file  336  may include digital information for an equalization signal that represents a difference between frequency response curve  640  and frequency response curve  610  over frequency band  670 . Second equalization file  336  may be applied to a drive signal for speaker  130  when the relationship of  FIG. 5C  is present so that frequency response curve  610  is produced at the output of speaker  130 .  
       Exemplary Method  
       [0061]      FIG. 7  is a flowchart of an exemplary method consistent with the principles of the invention. A communication session may be established between terminal  100  and another device (herein calling device), such as another mobile communications device or a landline telephone (act  710 ). A user of terminal  100  may speak into microphone  150  and may receive audio signals, such as speech associated with the calling party, via speaker  130  while participating in the communication session.  
         [0062]     Terminal  100  may determine the status of the user (act  720 ). For example, mobile terminal  100  may determine whether the user is holding terminal  100  to his/her ear and/or whether the user is operating terminal  100  in another manner, such as using a speaker phone feature of terminal  100 . When the user is operating terminal  100  proximate to his/her ear, acts  730  and  740  may be performed.  
         [0063]     Terminal  100  may monitor the output of speaker  130  when the user is engaged in a communication session with terminal  100  proximate to his/her ear, such as the relationships of  FIGS. 5A-5C  (act  730 ). For example, terminal  100  may monitor speaker  130  to determine whether the user is communicating with the calling party from a low background noise environment or a high background noise environment.  
         [0064]     In one implementation, terminal  100  may monitor an output of speaker  130  by determining a volume setting in use on terminal  100 . For example, terminal  100  may determine if the user has selected a volume setting of 0-3 (entry  402 ,  FIG. 4 ), 4-7 (entry  404 ,  FIG. 4 ) or 8-10 (entry  406 ,  FIG. 4 ). A volume setting of 0-3 may identify the user as being in a low background noise environment, a volume setting of 4-7 may identify the user as being in a mid background noise environment, and a volume setting of 8-10 may identify the user as being in a high background noise environment.  
         [0065]     In a second implementation, terminal  100  may monitor the output of speaker  130  using microphone  150 A. Microphone  150 A may receive acoustic signals from a front face of speaker  130 , acoustic signals associated with leakage through port  560 , and acoustic signals associated with background noise from the environment that the user is in while engaged in the communication session. When the user and terminal  100  are in the relationship of  FIG. 5B , microphone  150 A may receive background noise and leakage having first amplitudes, respectively. If the user and terminal  100  take on the relationship of  FIG. 5C , microphone  150 A may receive background noise and leakage having second amplitudes, respectively, that are lower than the respective first amplitudes. Processing logic  210  may process an output of microphone  150 A and may determine when the relationship of  FIG. 5C  is present.  
         [0066]     In a third implementation, terminal  100  may monitor the output of speaker  130  using a pressure sensor proximate to speaker  130 . For example, if the user and terminal  100  have the relationship of  FIG. 5B , a first pressure may be exerted on surface  106  ( FIG. 1 ) of terminal  100 . When the relationship of  FIG. 5C  is present, a second pressure, that is greater than the first pressure, may be exerted on surface  106 . Processing logic  210  may receive an output signal from the pressure sensor for the relationships of  FIG. 5B  and  FIG. 5C  and may process the pressure sensor signals in accordance with aspects of the invention.  
         [0067]     In a fourth implementation, terminal  100  may monitor output characteristics of speaker  130  by sensing an impedance of speaker  130 . For example, impedance feedback logic  328  may monitor an electrical input impedance to speaker  130 . An input impedance of speaker  130  may change as a function of an output frequency response for speaker  130 . Assume that a user operates terminal  100  according to the relationship of  FIG. 5B . Impedance feedback logic  328  may monitor a first impedance for speaker  130 . Further assume that the user then presses terminal  100  against his/her ear as shown in the relationship of  FIG. 5C . Impedance feedback logic  328  may monitor a second impedance for speaker  130  that is different than the first impedance for speaker  130 . Control logic  310  may be configured to apply a new equalization file  332  to speaker  130  via application logic  340  when the second impedance is detected.  
         [0068]     Speaker equalization may be applied based on a relationship between the user and terminal  100  (act  740 ). Control logic  310  may receive information from sensing logic  320  that is representative of an output of speaker  130 . For example, control logic  310  may receive acoustic feedback information  322  via microphone  150 A, volume setting information  324  via control keys  120 , pressure feedback information  326  via a pressure sensor proximate to speaker  130 , or impedance feedback information  328  via electrical or acoustical impedance detection components.  
         [0069]     Control logic  310  may determine if a frequency response for speaker  130  has deviated from a desired frequency response or a range of frequency responses. Control logic  310  may use amplitude characteristics and/or spectral characteristics (e.g., frequency distortion) to determine if a frequency response for speaker  130  has deviated from a desired range. For example, a desired frequency response for speaker  130  may be represented by frequency response curve  610  ( FIG. 6A ). Control logic  310  may determine that speaker  130  has a frequency response similar to frequency response  640  ( FIG. 6B ) based on information from sensing logic  320 . Control logic  310  may retrieve an equalization file  322  via retrieving logic  330 . For example, retrieving logic  330  may provide control logic  310  with nth equalization file  338 .  
         [0070]     Nth equalization file  338  may be configured to produce frequency response curve  610  at an output of speaker  130  when nth equalization file  338  is applied to an input signal of speaker  130  when the relationship of  FIG. 5C  is present. For example, processing logic  210  may receive a signal from antenna assembly  250  and communication interface  240  that includes speech information from the calling party. This speech information may be in the form of a digital input signal that can be used as an input signal to speaker  130 . Control logic  310  may provide nth equalization file  338  and the digital input signal to application logic  340 . Application logic  340  may combine the digital input signal and nth equalization file  338  to produce an equalized input signal that is sent to speaker  130 . The equalized input signal may be configured to produce frequency response curve  610  at an output of speaker  130  for a user and terminal  100  relationship, such as the user and terminal  100  relationship of  FIG. 5C .  
         [0071]     Terminal  100  may continue to monitor the output of speaker  130  and may remove nth equalization file  338  from the digital input signal via application logic  340  and/or may use additional equalization files  332 , such as first equalization file  334  or second equalization file  336  to maintain a desired frequency response curve at an output of speaker  130 .  
       CONCLUSION  
       [0072]     Implementations consistent with the principles of the invention may facilitate equalization of a frequency response for a speaker used in a handheld device. Implementations may monitor an output frequency response for a speaker and may apply equalization signals when the output frequency response deviates from a desired shape. Implementations, may apply substantially any number of equalization signals thus allowing terminal  100  to provide desired output frequency responses for the speaker for varying relationships between a user and terminal  100  and for varying environmental characteristics that the user and terminal  100  are operating in, such as high background noise environments.  
         [0073]     The foregoing description of preferred embodiments of the invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention.  
         [0074]     While a series of acts has been described with regard to  FIG. 7 , the order of the acts may be modified in other implementations consistent with the principles of the invention. Further, non-dependent acts may be performed in parallel.  
         [0075]     It will be apparent to one of ordinary skill in the art that aspects of the invention, as described above, may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement aspects consistent with the principles of the invention is not limiting of the invention. Thus, the operation and behavior of the aspects were described without reference to the specific software code—it being understood that one of ordinary skill in the art would be able to design software and control hardware to implement the aspects based on the description herein.  
         [0076]     It should be emphasized that the term “comprises/comprising” when used in this specification and/or claims is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.  
         [0077]     No element, act, or instruction used in the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.