Abstract:
A system with an input amplifier to receive and amplify a first audio signal, an output amplifier to output an audio signal which includes at least one of the amplified first audio signal and a second audio signal, a controller to adjust the input amplifier to a first input amp gain and the output amplifier to a first output amp gain to provide an output signal including the first audio signal at a first output signal level. The controller is to adjust the output amplifier to a second output amp gain to provide an audio output including the second audio signal at a second output signal level and determine an output amp ratio by dividing the first output amp gain with the second output amp gain. The controller is to determine a target input amp gain by multiplying the first input amp gain by the output amp ratio and adjust the first input amp gain to the target input amp gain to provide an audio output including the first audio signal at a third output signal level.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    Embodiments of the present invention generally relate to signal processing. More specifically, embodiments of the present invention relate to audio signal processing. 
         [0003]    2. Description of the Related Art 
         [0004]    Multi-function audio/video (“A/V”) devices are rapidly becoming the Swiss Army knife of the 21 st  century. The use of multifunction A/V devices as television screens, gaming system displays, audio-visual entertainment system displays, and computer displays makes the utilitarian nature of the A/V display device readily apparent. The functionality of multi-function A/V devices can be further enhanced by providing one or more connection points, usually modular “industry standard” connectors on the exterior surface of the device to permit the attachment of various external, peripheral devices such as gaming systems or DVD players. 
         [0005]    Quite frequently, however, various devices capable of providing an audio signal to the display device will transmit the audio signal at a default audio level. Frequently, when a user switches from one audio device to another audio device, the audio level will be either unacceptably high or low. The disparate audio levels can occasionally cause damage to the audio device or the hearing of an unfortunate listener. 
       SUMMARY OF THE INVENTION 
       [0006]    A method for auto-leveling a plurality of audio signals is provided. A first audio signal can be introduced to a system comprising a first audio input, a first input amplifier having a feedback controller operably connected thereto, and a first audio output. A second audio signal can be introduced to the system further comprising a second audio input and a second audio output. An output amplifier can be connected to the first and second audio outputs. The input amplifier gain can be adjusted to a first input amp gain and the output amp gain can be adjusted to a first output amp gain to provide a system output of the first audio signal at a first output signal level. The first input amp gain and the first output amp gain can be stored in a non-volatile memory disposed in, on, or about the system. The output amp gain can be adjusted to a second output amp gain to provide a system output of an amplified second audio signal at a second output signal level. An output amp ratio, equal to the first output amp gain divided by the second output amp gain, can be intermittently or continuously calculated and the result stored in the non-volatile memory. The first input amplifier gain can be adjusted using the feedback controller by amount equal to the first input amp gain multiplied by the output amp ratio, to provide a system output of the first audio signal at a third output signal level. 
         [0007]    As used herein, an “audio signal” refers to any signal, analog or digital, containing, all or in part, audio information or data. 
         [0008]    As used herein, an “amplifier” refers to any device, mechanical, electrical or any combination thereof, capable of changing the amplitude of a signal. The relationship of the input to the output of an amplifier, generally expressed as a function of the input frequency, is typically referred to as the “transfer function” of the amplifier, with the magnitude of the transfer function termed the “gain” of the amplifier. 
         [0009]    As used herein, an “output signal level&#39; refers to the audio output level of a device. Such an output signal level is frequently referred to colloquially as the “volume” of a device or appliance. The output signal level, when referring to the “volume” of a device is typically measured in Decibels (“db”). Other parameters can also be used to characterize into “output signal level” as used herein, including without limitation, the following: frequency response, total harmonic distortion (“THD”), intermodulation distortion (“IMD”), noise, crosstalk, common-mode rejection ratio, dynamic range, signal-to-noise ratio, phase distortion, group delay, phase delay, transient response, damping factor, jitter, sample rate, bit depth, sample accuracy and synchronization, linearity, or any combination thereof. 
         [0010]    As used herein, an “operable connection”, or a connection by which entities are “operably connected”, is one in which signals, physical communications, and/or logical communications may be sent and/or received. Typically, an operable connection includes a physical interface, an electrical interface, and/or a data interface, but it is to be noted that an operable connection may include differing combinations of these or other types of connections sufficient to allow operable control. For example, two entities can be operably connected by being able to communicate signals to each other directly or through one or more intermediate entities like a processor, operating system, a logic circuit, software, or other entity. Logical and/or physical communication channels can be used to create an operable connection. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Advantages of one or more disclosed embodiments may become apparent upon reading the following detailed description and upon reference to the drawings in which: 
           [0012]      FIG. 1  is a schematic depicting an illustrative system for leveling a plurality of audio signals, according to one or more embodiments described herein; 
           [0013]      FIG. 2  is a schematic depicting an illustrative system using the system depicted in  FIG. 1  for leveling a plurality of audio signals, according to one or more embodiments described herein; and 
           [0014]      FIG. 3  is a logic flow diagram depicting an illustrative method for leveling a plurality of audio signals using the system depicted in  FIG. 1 , according to one or more embodiments described herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]      FIG. 1  is a schematic depicting an illustrative system  100  for leveling a plurality of audio signals, according to one or more embodiments. In one or more embodiments, a first audio input  105  and a second audio input  120  can be disposed in, on, or about a system  100 . In one or more embodiments, the first audio input  105  can be operably connected to one or more input amplifiers (“input amps”)  140 . In one or more embodiments, the one or more input amps  140  can be operably connected to a device controller  150 . A first source  190  can be operably connected to the first audio input  105  to provide the first audio signal  110 . In one or more embodiments, the one or more device controllers  150  can include one or more feedback controllers providing a feedback signal  115  to the first audio input  105 , and to any device  190  operably connected to the first audio input  105 . 
         [0016]    In one or more embodiments, the device controller  150  can be operably connected to one or more output amplifiers (“output amps”)  160  and one or more non-volatile memory modules  180 . In one or more embodiments, the one or more output amps  160  can be operably connected to one or more audio outputs  170 . In one or more embodiments, the second audio input  120  can be operably connected to the device controller  150 . An external device  195 , for example an external audio signal generator, can be operably connected to the second audio input  120  to provide the second audio signal  125 . In one or more embodiments, the one or more input amps  140 , device controllers  150 , output amps  160 , one or more audio outputs  170 , and the non-volatile memory  180  can be disposed in whole or in part, in, on, or about the system  100 . 
         [0017]    In one or more embodiments, the first audio signal  110  can be generated or otherwise transmitted from one or more first sources  190  to the one or more first audio inputs  105 . The one or more first audio signals  110  can include, but are not limited to, one or more analog signals, one or more digital signals or any combination thereof. In one or more embodiments, the one or more first audio signals  110  can provide all or a portion of another signal, for example the one or more first audio signals  110  can be a portion of an audio/visual (“A/V”) signal containing both audio and video data. 
         [0018]    The one or more first audio inputs  105  can include any connector suitable for providing one or more operable connections between the one or more input amplifiers  140  and the first source  190 . In one or more embodiments, the one or more first audio inputs  105  can include one or more permanent type connectors, for example a soldered or one-way blade type connection that resists or prevents detachment. In one or more embodiments, the first audio inputs  105  can include one or more temporary or detachable connectors, for example screw type connectors, modular connectors, or blade-type connectors that permit or otherwise facilitate detachment. The one or more first audio inputs  105  can include one or more individual conduits or connectors. In one or more embodiments, the one or more first inputs  105  can comprise one or more modular connectors compliant with one or more industry standards applicable to video transmission cables or devices. Exemplary first audio inputs  105  can include, but are not limited to: one or more RCA type coaxial connectors; one or more High Definition Multimedia Interface (“HDMI”); one or more IEEE 1394 (“Firewire” or “Link”) multi-conductor connectors; or any combination thereof. 
         [0019]    In one or more embodiments, the second audio signal  125  can be generated or otherwise transmitted from one or more second sources  195  to the one or more second audio inputs  120 . The one or more second audio signals  125  can include, but are not limited to, one or more analog signals, one or more digital signals or any combination thereof. In one or more embodiments, the one or more second audio signals  125  can provide all or a portion of an audio signal, for example the one or more second audio signals  125  can be a portion of an audio/visual (“A/V”) signal containing both audio and video data. 
         [0020]    In one or more specific embodiments, the one or more second audio signals  125  can be introduced to one or more device controllers  150  via the one or more second audio inputs  120 . The second audio input  120  can include any connector suitable for providing one or more operable connections between the second source  195  and the one or more device controllers  150 . In one or more embodiments, the second audio input  120  can include one or more permanent type connectors, for example a soldered or one-way blade type connection resistant to separation or detachment. In one or more embodiments, the second audio input  120  can include one or more temporary or detachable connectors, for example screw type connectors, modular connectors, or blade-type connectors that permit or otherwise facilitate detachment. The second audio input  120  can include one or more individual conduits or connectors. In one or more embodiments, the second audio input  120  can comprise one or more modular connectors compliant with one or more industry standards applicable to video transmission cables or devices. Exemplary modular second audio inputs  120  can include, but are not limited to: one or more RCA type coaxial connectors; one or more High Definition Multimedia Interface (“HDMI”); one or more IEEE 1394 (“Firewire” or “iLink”) multi-conductor connectors; or any combination thereof. 
         [0021]    In one or more embodiments, the one or more first audio signals  110  can be introduced to one or more input amplifiers (“input amps”)  140  via one or more first audio inputs  105 . The one or more input amps  140  can include, but are not limited to, one or more electrical, mechanical or electro-mechanical systems, devices, or combination of systems and/or devices suitable for amplifying the first audio signal  110  to provide an amplified first audio signal  145 . In one or more embodiments, the one or more input amps  140  can include, but are not limited to, one or more transistor amplifiers. In one or more specific embodiments, the one or more input amps  140  can include, but are not limited to one or more bipolar junction transistor (“BJT”) amplifiers, one or more metal oxide semiconductor field effect transistor (“MOSFET”) amplifiers, or the like. In one or more embodiments, the one or more input amps  140  can have a single stage or multiple stages. 
         [0022]    In one or more embodiments, one or more feedback controllers can be used to adjust the gain of the one or more input amplifiers  140 . In one or more embodiments, the one or more feedback controllers can be disposed in, on, or about the device controller  150 . In one or more embodiments, one or more feedback signals  115  can operatively connect the one or more feedback controllers to the one or more input amplifiers  140 . In one or more embodiments, the value of the input amp gain transmitted or otherwise transferred from the device controller  150  to the one or more input amplifiers  140  via the one or more signals  115  can be stored or otherwise archived in a non-volatile memory  180  operably connected to the device controller  150 . In one or more embodiments, the non-volatile memory  180  can be disposed remote from the device controller  150 . In one or more embodiments, the non-volatile memory  180  can be partially or completely disposed in, on, or about the device controller  180 . 
         [0023]    While the one or more input amplifiers  140  can be disposed within the housing  185  as depicted in  FIG. 1 , in one or more specific embodiments, all or a portion of the one or more amplifiers  140  can be disposed in, on, or about the first source  190 . In one or more embodiments, the one or more feedback signals  115  can be generated or otherwise transmitted by the device controller  150 . 
         [0024]    In one or more specific embodiments, either, or both, the amplified first audio signal  145  and/or the second signal  125  can be introduced to one or more device controllers  150 . The one or more device controllers  150  can include, but is not limited to one or more systems, devices, or any combination of systems and/or devices suitable for transmission, routing, modification, enhancement, adjustment or any combination thereof, of one or more audio signals. In one or more specific embodiments, the device controller  150  can include, but is not limited to a panel controller, suitable for the transmission, generation, and/or control of one or more video signals, one or more audio signals, or one or more combined audio/visual (“A/V”) signals. In one or more specific embodiments, the one or more device controllers  150  can include, but are not limited to, one or more flat panel controllers disposed in, on, or about a computing device, for example, an all-in-one personal computer. 
         [0025]    In one or more embodiments, one or more audio signals  155  can operatively connect the one or more device controllers  150  with one or more output amps  160 . In one or more embodiments, the one or more output amps  160  can include, but are not limited to, one or more electrical, mechanical or electro-mechanical systems, devices, or combination of systems and/or devices suitable for amplifying the audio signal  155  supplied via the device controller  150  to provide a system audio output signal  165 . In one or more embodiments, the one or more output amps  160  can include, but are not limited to, one or more transistor amplifiers. In one or more specific embodiments, the one or more output amps  160  can include, but are not limited to one or more bipolar junction transistor (“BJT”) amplifiers, one or more metal oxide semiconductor field effect transistor (“MOSFET”) amplifiers, or the like. In one or more embodiments, the one or more output amps  160  can include a single stage or multiple stages. 
         [0026]    In one or more embodiments, the output amp  160  gain can be manually set, in whole or in part. In one or more specific embodiments, the output amp gain can be manually adjusted using an adjustment device  130 . In one or more embodiments, the adjustment device  130  can include, but is not limited to, one or more mechanical, electrical, or electromechanical adjustment devices disposed in, on, or about the system  100 . In one or more embodiments, the adjustment device  130  can include, but is not limited to, one or more remote adjustment devices operably coupled, directly or indirectly, to the gain control on the output amp  160 . 
         [0027]    Typical mechanical or electro-mechanical adjustment devices  130  can include, but are not limited to, knobs, dials, rocker switches, pushbuttons, or any combination thereof. Typical electrical, or electro-mechanical adjustment devices  130  can include, but are not limited to, electronic switches, sliders, and the like, for example, one or more interactive sliders provided by software on a computer display. In one or more embodiments, the output amp gain can be signaled, transmitted or otherwise communicated to the device controller  150  via one or more signals  175 . In one or more embodiments, although not depicted in  FIG. 1 , the output amp gain can be signaled, transmitted or otherwise communicated to the panel controller  150 , and retransmitted by the panel controller  150  to the one or more output amps  160 . In one or more embodiments, the value of the output amp gain can be stored or otherwise archived in the non-volatile memory  180 . 
         [0028]    In one or more embodiments, the output signal  165  can be transmitted, transferred, or otherwise communicated via one or more audio outputs  170 . In one or more embodiments, the one or more audio outputs  170  can include one or more permanent type connectors, for example a soldered or one-way blade type connection that resists or prevents detachment. In one or more embodiments, the one or more audio outputs  170  can include one or more temporary or detachable connectors, for example screw type connectors, modular connectors, or blade-type connectors that permit or otherwise facilitate detachment. 
         [0029]      FIG. 2  is a schematic depicting an illustrative system  200  using the system  100  depicted in  FIG. 1  for leveling a plurality of audio signals, according to one or more embodiments. In one or more embodiments, the audio leveling system  100  can be disposed, wholly or partially, in, on, or about a housing  290 . In one or more embodiments, the first audio source  190  can also disposed wholly or partially, in, on, or about the housing  290 . In one or more embodiments, the first audio source can include, but is not limited to, one or more central processing units (“CPUs”)  210 , one or more memory modules  220 , one or more audio processing modules  230 , and one or more busses  240 . In one or more embodiments, one or more video display devices  270  and one or more audio output devices  280  can be disposed in, on, or about the housing  290 . 
         [0030]    In one or more embodiments, the one or more busses can bi-directionally, operatively connect the one or more central processing units (“CPUs”)  210 , one or more memory modules  220 , and one or more audio processing modules  230 . In one or more embodiments, all or a portion of the first audio signal  110  can be transported, transmitted, propagated, or otherwise communicated via the one or more busses  240 . In one or more embodiments, all or a portion of the one or more feedback signals  115  can be communicated via the one or more busses  240 . 
         [0031]    in one or more embodiments, the one or more CPUs  210  can include one or more devices, systems, or any combination of systems and/or devices suitable for execution of one or more machine readable instruction sets. In one or more embodiments, the one or more CPUs  210  can be a dedicated device such as one of the family of Intel Pentium, Celeron, Xeon, Itaniurn microprocessors, or the like. In one or more embodiments, the one or more CPUs  210  can be a portion of a device such as a RISC based processor in a simple electronic device, or the like. In one or more embodiments, the one or more CPUs  210  can be operably connected with the one or more memory modules  220 , and/or then one or more audio processing modules  230  via the one or more busses  240 . In one or more embodiments, the one or more processors  210  can receive all or part of the one or more signals  115  transmitted from the first input  105  via the one or more busses  240 . In one or more embodiments, the one or more CPUs  210  can include, but is not limited to, one or more 8-bit CPUs; one or more 16-bit CPUs; one or more 32-bit CPUs, one or more 64-bit CPUs, one or more 128-bit CPUs; one or more 256-bit CPUs; one or more 512-bit CPUs; one or more 1024-bit CPUs; one or more 2048-bit CPUs; or any combination thereof. 
         [0032]    The one or more memory modules  220  can include one or more devices, systems, or any combination of systems and/or devices suitable for the temporary or permanent storage of digital data. In one or more embodiments, one or more memory modules  220  can include computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) and/or random access memory (RAM). A basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within the first audio source  190 , for example during start-up, can be stored in ROM. RAM can contain data and/or program modules that are immediately accessible to and/or presently being operated on by the one or more CPUs  210 . In one or more embodiments, the one or more memory modules  220  can receive all or part of the one or more feedback signals  115  transmitted from the first input  105  via the one or more busses  240 . In one or more embodiments, the one or more memory modules  220  can be partially or wholly physically and/or electrically detachable or otherwise removable from the computing device  190 . 
         [0033]    The one or more audio processing modules  230  can include one or more devices, systems, or any combination of systems and/or devices suitable for the conversion of audio data communicated by the one or more CPUs  210  and/or the system memory  220  to provide all or a portion of the first audio signal  110 . The one or more audio processing modules  230  can be combined, in whole or in part, with the one or more CPUs  210  and/or the one or more memory modules  220 . In one or more embodiments, the one or more audio processing modules  230  can be a dedicated audio device, for example a sound card, disposed in, on, or about a computing device  190 , such as a personal computer, a workstation, a game console, or the like. 
         [0034]    The one or more busses  240  can include one or more devices, systems, or any combination of systems and/or devices suitable for the transmission or conveyance of digital data between one or more systems and/or devices, for example one or more CPUs  210 , one or more memory modules  220 , one or more audio processing modules  230 , or any frequency and/or combination thereof. The one or more busses  240  can convey digital data in serial fashion or in parallel fashion. In one or more embodiments, the one or more audio processing modules  230  can transmit all or part of the first signal  110  to the first input  105  via the one or more busses  240 . In one or more embodiments, the one or more audio processing modules  230  can receive all or part of the one or more feedback signals  115  transmitted from the first input  105  via the one or more busses  240 . In one or more embodiments, the one or more busses can include one or more parallel busses having a width of: 8-bits or greater; 16-bits or greater; 32-bits or greater; 64-bits or greater; 128-bits or greater; 256-bits or greater; or 512-bits or greater. 
         [0035]    The one or more audio output devices  270  can include one or more devices, systems, or any combination of systems and/or devices suitable for the conversion of an analog, digital, or any combination thereof audio signal to one or more waveforms audible to the human ear. The one or more audio output devices  270  can include, but are not limited to, one or more dynamic enclosure speakers, one or more electrostatic speakers, one or more horn-type speakers, one or more planar-magnetic speakers, one or more subwoofers, or the like, in any combination or frequency. In one or more embodiments, the one or more audio output devices  270  can be disposed partially or wholly, in, on, or about the enclosure  290 . 
         [0036]    The one or more display devices  280  can include one or more systems, devices, or any combination of systems and/or devices suitable for the display of one or more video images. The one or more display devices  280  can include, but are not limited to, one or more gas plasma display devices, one or more liquid crystal display (“LCD”) display devices, one or more light emitting diode (“LED”) display devices, one or more cathode ray tube (“CRT”) display devices, one or more organic LED (“OLEO”) display devices, one or more surface conduction electron-emitter (“SED”) display devices, or the like. The one or more display devices  280  can be disposed in whole or in part in, on, or about the housing  290 . In one or more embodiments, the one or more display devices  280  can include, but are not limited to, display devices having a diagonal dimension of 5 inches (12.7 cm) or more; 8 inches (20.3 cm) or more; 12 inches (30.5 cm) or more; 19 inches (48.3 cm) or more; 24 inches (61 cm) or more; 36 inches (91,4 cm) or more; 48 inches (122 cm) or more; or 60 inches (152.4 cm) or more. 
         [0037]    In one or more embodiments, the one or more display devices  280  can be suitable for the display of a video signal having any color space format. In one or more embodiments, the one or more display devices  280  can be suitable for the display of a video signal in a single color space format, for example a video signal in an RGB, sRGB, or xvYcc color space format. In one or more specific embodiments, the one or more display devices  280  can be suitable for the display of a video signal in a plurality of color space formats, for example a video signal having either an RGB, sRGB, or xvYcc color space format. 
         [0038]    In one or more embodiments, the housing  290  can include any system, device, or any combination of systems and/or devices suitable for partially or completely housing all or a portion of the one or more color space matching system  100 , one or more CPUs  210 , one or more memory modules  220 , one or more audio processing modules  230 , one or more busses  240 , and one or more display devices  280 . In one or more embodiments, the housing  290  can include, but is not limited to, a portable computer case, a laptop computer case, a “netbook” computer case, a desktop computer case, a workstation computer case, or the like. In one or more specific embodiments, the housing can include an “all-in-one” computer case having at least the display and motherboard mounted, in whole or in part, within a single housing  290 . 
         [0039]      FIG. 3  is a logic flow diagram  300  depicting an illustrative method for leveling a plurality of audio signals using the system  100  depicted in  FIG. 1 , according to one or more embodiments. In one or more embodiments, the system can include a first audio source  190  transmitting or otherwise supplying one or more one or more first audio signals  110  to the first audio input  105  disposed in, on, or about the system  100 . In one or more embodiments, the system can also include a second audio source  195  transmitting or otherwise supplying one or more second audio signals  125  to the second audio input  120 . 
         [0040]    In one or more embodiments, in step  305 , the first audio signal  110 , can be introduced to the first audio input  105 . In one or more embodiments, all or a portion of the first audio signal  110  can be digital, analog or any combination thereof. From the first input  105 , the first audio signal  110  can be introduced to the input amp  140 . hi one or more embodiments, in step  310 , the input amp  140  gain can be adjusted to a first input amp gain. In one or more embodiments, the input amplifier gain  140  can be adjusted using one or more electrical, mechanical, or electro-mechanical devices, for example one or more rheostats, capacitive switches, sliders, knobs, buttons, or wheels. In one or more specific embodiments, the input amp  140  gain can be adjusted using one or more software routines, for example by adjusting a volume slider control in a Microsoft® Windows® environment. 
         [0041]    The amplified first audio signal  145  can be introduced to one or more device controllers  150 . The device controller  150  can, in turn, retransmit, rebroadcast or otherwise communicate the amplified first audio signal  145 , in whole or in part, as an audio signal  155 . The audio signal  155  can, in turn, be introduced to the output amp  160 . In one or more embodiments, in step  315 , the output amp  160  gain can be adjusted to a first output amp gain. In one or more embodiments, the output amp gain can be adjusted using one or more electrical, mechanical, or electro-mechanical devices  135 , for example one or more rheostats, capacitive switches, sliders, knobs, buttons, or wheels. 
         [0042]    In one or more embodiments, in step  320 , the first input amp gain and the first output amp gain can be stored in one or more memory modules, for example in the non-volatile memory  180  disposed in, on, or about the system  100 , or in the one or more memory modules  220  disposed in, on, or about the first source  190 . In one or more specific embodiments, the first input amp gain and the first output amp gain can be stored in a non-volatile memory  180  operatively coupled to the device controller  150 . In one or more specific embodiments, the first input amp gain and the first output amp gain can be stored in a non-volatile memory  180  operatively coupled to the device controller  150  disposed in, on, or about an all-in-one computer enclosure  290 . 
         [0043]    In one or more embodiments, in step  325 , the second audio signal  125  can be introduced to the second audio input  120 . In one or more embodiments, all or a portion of the second audio signal  125  can be digital, analog or any combination thereof. From the second input  120 , all or a portion of the second audio signal  125  can be introduced to the device controller  150 . The device controller  150  can, in turn, retransmit, rebroadcast or otherwise communicate the second audio signal  125 , in whole or in part, as the audio signal  155 . The audio signal  155  can, in turn, be introduced to the output amp  160 . In one or more embodiments, in step  330 , the output amp  160  gain can be adjusted to a second output amp gain. 
         [0044]    in one or more embodiments, in step  335 , the output amp ratio defined as the first output amp gain divided by the second output amp gain, can be calculated. In one or more embodiments, the output amp ratio can be calculated, in whole or in part, using all or a portion of the device controller  150 , based on the gain values stored in the non-volatile memory  180 . In one or more embodiments, the output amp ratio can be calculated, in whole or in part, using all or a portion of the one or more CPUs  210 , based on the gain values stored in the non-volatile memory  180  or the one or more memory modules  220 . 
         [0045]    By way of example, if the first output amp gain has a value of about 4.2 and the second output amp gain has a value of about 8.6, the output amp ratio would be equal to 4.2 divided by 8.6 or about 0.49. In one or more specific embodiments, the output amp ratio can be stored in the non-volatile memory  180 . In one or more specific embodiments, the output amp ratio can be calculated intermittently on a temporal basis, for example on a time basis, e.g. once per second, every ten seconds, etc. In one or more specific embodiments, the output amp ratio can be calculated intermittently on an event driven basis, for example when a change in the second output amp gain is sensed by the device controller  150 . In one or more specific embodiments, the output amp ratio can be calculated continuously. 
         [0046]    In one or more embodiments, in step  340 , the output amp ratio can be used to calculate a target input amp gain defined as the first input amp gain multiplied by the output amp ratio. By way of example, if the first input amp gain has a value of about 5.6, and the first output amp gain has a value of about 4.2, and the second output amp gain has a value of about 8.6, the output amp ratio would be equal to 4.2 divided by 8.6 or about 0.49, and the target input amp gain would be equal to (4.2 divided by 8.6) times 5.6, or about 2.7. 
         [0047]    In one or more specific embodiments, the target input amp gain can be stored in the non-volatile memory  180 . In one or more specific embodiments, the target input amp gain can be calculated intermittently on a temporal basis, for example on a time basis, e.g. once per second, every ten seconds, etc. In one or more specific embodiments, the target input amp gain can be calculated intermittently on an event driven basis, for example when a change in the second output amp gain is sensed by the device controller  150 . In one or more specific embodiments, the target input amp gain can be calculated continuously. 
         [0048]    In one or more embodiments, in step  345 , the input amp gain can be adjusted by the device controller  150  using the feedback signal  115  to a level equal to the target input amp gain calculated in step  340 . In one or more specific embodiments, the input amp gain can be adjusted intermittently on a temporal basis, for example on a time basis, e.g. once per second, every ten seconds, etc. In one or more specific embodiments, the input amp gain can be adjusted intermittently on an event driven basis, for example when a change in the second output amp gain is sensed by the device controller  150 . In one or more specific embodiments, the input amp gain can be adjusted continuously. Since the input amp gain can be adjusted intermittently or continuously by the device controller  150  via the feedback signal  115 , output audio signal level fluctuations upon awakening of the one or more CPUs  210 , for example from an ACPI S3 or 34 sleep mode, can be minimized. 
         [0049]    Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges from any lower limit to any upper limit are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below. All numerical values are “about” or “approximately” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art. 
         [0050]    Various terms have been defined above. To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted. 
         [0051]    While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.