Abstract: An acoustic signal processing system and method includes classification technology to classify a relationship between at least two sound components of a received sound signal. The exemplary sound components are ambient noise and localized noise. The classification technology dynamically determines a classification value that represents the relationship between the sound components and processes the sound signal in accordance with the acoustic signal classification to modify the sound signal. In at least one embodiment, dynamic classification of the relationship between sound components in a sound signal and responsive signal processing improve performance of systems, such as an active noise cancellation (ANC) system, by, for example, attenuating at least one of the sound components and/or enhancing at least one of the sound components. In an ANC system context, the sound components generally include noise components such as ambient noise and noise localized to a microphone.

Abstract: A system may include an electromagnetic load capable of generating a haptic event and a haptic processor configured to receive at least one first parameter indicative of a desired perception of the haptic event to a user of a device comprising the electromagnetic load, receive at least one second parameter indicative of one or more characteristics of the device, and process the at least one first parameter and the at least one second parameter to generate a driving signal to the electromagnetic load in order to produce the desired perception to the user despite variances in the device that cause an actual perception of the haptic event to vary from the desired perception.

Abstract: A system may include an electromagnetic load capable of generating a haptic event and a haptic processor configured to receive at least one first parameter indicative of a desired perception of the haptic event to a user of a device comprising the electromagnetic load, receive at least one second parameter indicative of one or more characteristics of the device, and process the at least one first parameter and the at least one second parameter to generate a driving signal to the electromagnetic load in order to produce the desired perception to the user despite variances in the device that cause an actual perception of the haptic event to vary from the desired perception.

Abstract: A system may include an electromagnetic load capable of generating a haptic event and a haptic processor configured to receive at least one first parameter indicative of a desired perception of the haptic event to a user of a device comprising the electromagnetic load, receive at least one second parameter indicative of one or more characteristics of the device, and process the at least one first parameter and the at least one second parameter to generate a driving signal to the electromagnetic load in order to produce the desired perception to the user despite variances in the device that cause an actual perception of the haptic event to vary from the desired perception.

Abstract: An integrated circuit for implementing at least a portion of a personal audio device may include an output for providing an output signal to a transducer, wherein the output signal includes a pilot signal, a microphone input for receiving a microphone signal from a microphone indicative of an output of the transducer, and a processing circuit. The processing circuit may be configured to implement a pilot signal control to apply an adjustment to the pilot signal as necessary to maintain the pilot signal at a substantially constant magnitude regardless of proximity of the transducer to a pinna and implement a proximity determination block configured to determine proximity of the transducer to the pinna based on the adjustment.

Abstract: A system may include an electromagnetic load capable of generating a haptic event and a haptic processor configured to receive at least one first parameter indicative of a desired perception of the haptic event to a user of a device comprising the electromagnetic load, receive at least one second parameter indicative of one or more characteristics of the device, and process the at least one first parameter and the at least one second parameter to generate a driving signal to the electromagnetic load in order to produce the desired perception to the user despite variances in the device that cause an actual perception of the haptic event to vary from the desired perception.

Abstract: An integrated circuit for implementing at least a portion of a personal audio device may include an output for providing an output signal to a transducer, wherein the output signal includes a pilot signal, a microphone input for receiving a microphone signal from a microphone indicative of an output of the transducer, and a processing circuit. The processing circuit may be configured to implement a pilot signal control to apply an adjustment to the pilot signal as necessary to maintain the pilot signal at a substantially constant magnitude regardless of proximity of the transducer to a pinna and implement a proximity determination block configured to determine proximity of the transducer to the pinna based on the adjustment.

Abstract: An integrated circuit for implementing at least a portion of a personal audio device may include an output for providing an output signal to a transducer, wherein the output signal includes a pilot signal, a microphone input for receiving a microphone signal from a microphone indicative of an output of the transducer, and a processing circuit. The processing circuit may be configured to implement a pilot signal control to apply an adjustment to the pilot signal as necessary to maintain the pilot signal at a substantially constant magnitude regardless of proximity of the transducer to a pinna and implement a proximity determination block configured to determine proximity of the transducer to the pinna based on the adjustment.

Abstract: In accordance with systems and methods of the present disclosure, a method may include receiving an error microphone signal indicative of an acoustic output of a transducer and ambient audio sounds at the acoustic output of the transducer. The method may also include generating an anti-noise signal to reduce the presence of the ambient audio sounds at the acoustic output of the transducer based at least on the error microphone signal. The method may further include generating an equalized source audio signal from a source audio signal by adapting, based at least on the error microphone signal, a response of the adaptive playback equalization system to minimize a difference between the source audio signal and the error microphone signal. The method may additionally include combining the anti-noise signal with the equalized source audio signal to generate an audio signal provided to the transducer.

Abstract: An integrated circuit may include an output for providing an output signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer, an ambient microphone input for receiving an ambient microphone signal indicative of the ambient audio sounds; an error microphone input for receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer; and a processing circuit that implements a feedback path having a feedback response that generates a feedback anti-noise signal from the error microphone signal, wherein a signal gain of the feedback path is a function of the ambient microphone signal, and wherein the anti-noise signal comprises at least the feedback anti-noise signal.

Abstract: The handling of disturbances to audio signals may be improved with an adaptive noise cancellation (ANC) system that performs tone suppression and howl suppression in a collaborative manner. Such ANC systems may be configured to detect a first tone in an input signal at a first tone frequency and extract the detected first tone from the input signal. The ANC systems may also be configured to adaptively filter the extracted first tone to generate a second tone that has a magnitude that is approximately equal to a magnitude of the extracted first tone and a phase that is approximately opposite the phase of the extracted first tone. The ANC systems may be further configured to add the second tone to an intermediate signal that is based, at least in part, on the input signal to generate the output signal.

Abstract: A method may include adaptively generating an anti-noise signal from filtering a reference microphone signal with an adaptive filter in conformity with an error microphone signal and the reference microphone signal. The method may also include adjusting the response of the adaptive filter by combining injected noise with the reference microphone signal and receiving the injected noise by a copy of the adaptive filter so that the response of the copy is controlled by the adaptive filter adapting to cancel a combination of the ambient audio sounds and the injected noise and controlling the response of the adaptive filter with the coefficients adapted in the copy, whereby the injected noise is not present in the anti-noise signal and wherein each of a sample rate of the copy and a rate of adapting of the adaptive filter is significantly less than a sample rate of the adaptive filter.

Abstract: In accordance with the present disclosure, an integrated circuit for implementing at least a portion of a personal audio device may include an output and a processing circuit. The output may provide an output signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer. The processing circuit may implement an adaptive noise cancellation system that generates the anti-noise signal to reduce the presence of the ambient audio sounds heard by the listener by adapting, based on a presence of the source audio signal, a response of the adaptive noise cancellation system to minimize the ambient audio sounds at the acoustic output of the transducer, wherein the adaptive noise cancellation system is configured to adapt both in the presence and the absence of the source audio signal.

Abstract: The handling of disturbances to audio signals may be improved with an adaptive noise cancellation (ANC) system that performs tone suppression and howl suppression in a collaborative manner. Such ANC systems may be configured to detect a first tone in an input signal at a first tone frequency and extract the detected first tone from the input signal. The ANC systems may also be configured to adaptively filter the extracted first tone to generate a second tone that has a magnitude that is approximately equal to a magnitude of the extracted first tone and a phase that is approximately opposite the phase of the extracted first tone. The ANC systems may be further configured to add the second tone to an intermediate signal that is based, at least in part, on the input signal to generate the output signal.

Abstract: In accordance with the present disclosure, an adaptive noise cancellation system may include a controller. The controller may be configured to determine a degree of convergence of an adaptive coefficient control block for controlling an adaptive response of the adaptive noise cancellation system. The controller may enable adaptation of the adaptive coefficient control block if the degree of convergence of the adaptive response is below a particular threshold and disable adaptation of the adaptive coefficient control block if the degree of convergence of the adaptive response is above a particular threshold, such that when the adaptive noise cancellation system is adequately converged, the adaptive noise cancellation system may conserve power by disabling one or more of its components.

Abstract: An integrated circuit may include an output for providing a signal to a transducer including both source audio for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer, a microphone input for receiving a microphone signal indicative of ambient sounds at the transducer, a link control input for receiving link control information of a communications link coupling the integrated circuit to the transducer and/or a microphone for generating the microphone signal, wherein the link control information includes a link quality metric of the communications link, and a processing circuit comprising a filter having a response that generates the anti-noise signal in conformity with the microphone signal to minimize the ambient sounds at the acoustic output of the transducer, wherein the processing circuit modifies generation of the anti-noise signal responsive to the link quality metric.

Abstract: A method may include adaptively generating an anti-noise signal for countering the effects of ambient audio sounds at an acoustic output of the transducer by adapting a response of an adaptive filter that filters a reference microphone signal in conformity with an error microphone signal and the reference microphone signal to minimize the ambient audio sounds in the error microphone, generating a scaled anti-noise signal by applying a scaling factor to the anti-noise signal, further adjusting the response of the adaptive filter independent of a source audio signal by altering an input to the coefficient control block of the adaptive filter to compensate for the scaling factor, and combining the scaled anti-noise signal with the source audio signal to generate an audio signal provided to the transducer.

Abstract: A method may include adaptively generating an anti-noise signal for countering the effects of ambient audio sounds at an acoustic output of the transducer by adapting a response of an adaptive filter that filters a reference microphone signal in conformity with an error microphone signal and the reference microphone signal to minimize the ambient audio sounds in the error microphone, generating a scaled anti-noise signal by applying a scaling factor to the anti-noise signal, further adjusting the response of the adaptive filter independent of a source audio signal by altering an input to the coefficient control block of the adaptive filter to compensate for the scaling factor, and combining the scaled anti-noise signal with the source audio signal to generate an audio signal provided to the transducer.

Abstract: Accessing a circular buffer in memory from a processor may be performed with the aid of precomputed values stored in a pointer descriptor field of a processor storage element, such as a register. The pointer descriptor may store a precomputed value for calculating a memory address in the circular buffer, which may include two values, in which the two values are based, at least in part, on the size of the circular buffer, but neither be the size of the circular buffer. The first value may be used to derive a starting memory location for a circular buffer. The second value may be used in combination with the first value to calculate an end memory location. The start and end locations or addresses, along with the precomputed stored values, are then used to calculate the next address based on the current address of a circular buffer in an efficient manner.

Abstract: An integrated circuit may include an output for providing an output signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer, an ambient microphone input for receiving an ambient microphone signal indicative of the ambient audio sounds; an error microphone input for receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer; and a processing circuit that implements a feedback path having a feedback response that generates a feedback anti-noise signal from the error microphone signal, wherein a signal gain of the feedback path is a function of the ambient microphone signal, and wherein the anti-noise signal comprises at least the feedback anti-noise signal.