Abstract: An anti-noise signal is produced in accordance with an active noise cancellation process (ANC), at an input of a speaker so as to control how much background noise a user can hear. Strength of the anti-noise signal is adjusted gradually, rather than abruptly, in proportion to decreasing or increasing sound pressure level (SPL) of the background noise, during inactivation or activation of the ANC process. Other embodiments are also described and claimed.

Abstract: An audio processor has an active noise cancellation (ANC) processor to compute an S-filter, which estimates a transfer function from an earpiece speaker, that is to be worn by a user, to an error microphone. The ANC processor adaptively produces an anti noise signal for reducing ambient noise that can be heard by the user. An adaptive equalization (EQ) processor has an EQ filter controller that adjusts an EQ filter, while audio user content is being filtered in accordance with the EQ filter before being fed to the speaker and then heard by the user. Other embodiments are also described and claimed.

Abstract: In one aspect, multiple adaptive W filters and associated adaptive filter controllers are provided that use multiple reference microphone signals to produce multiple, “component” anti-noise signals. These are gain weighted and summed to produce a single anti-noise signal, which drives an earpiece speaker. The weighting changes based on computed measures of the coherence between content in each reference signal and content in an error signal. Other embodiments are also described and claimed.

Abstract: An accessory having an earbud for insertion into a user's ear is disclosed. The earbud may include a speaker and a microphone in which the speaker plays an audio signal for the user and the microphone receives the audio signal. The accessory includes a processor that is coupled to the speaker and the microphone to execute various operations. For example, the operations may include: determining a ratio of an energy estimation of the speaker audio signal to an energy estimation of the audio signal received by the microphone; determining a gain for the speaker audio signal based upon the ratio; based upon the gain, selecting a shelving filter; and applying the shelving filter to the speaker audio signal.

Abstract: An active noise control (ANC) processor has an adaptive filter that uses a reference signal to produce an anti-noise signal, and an error signal to evaluate cancellation performance. An adaptive filter algorithm engine configures the filter coefficients of the adaptive filter, in accordance with pre-shaped versions of the error and reference signals. The pre-shaping filter has a high-pass transfer function and enables the adaptive algorithm engine to increase noise cancellation performance in a high frequency band during the presence of focused or narrow-band noise energy in a low frequency band. Other embodiments are also described and claimed.

Abstract: An anti-noise signal is produced in accordance with an active noise cancellation process (ANC), at an input of a speaker so as to control how much background noise a user can hear. Strength of the anti-noise signal is adjusted gradually, rather than abruptly, in proportion to decreasing or increasing sound pressure level (SPL) of the background noise, during inactivation or activation of the ANC process. Other embodiments are also described and claimed.

Abstract: An audio processor has an active noise cancellation (ANC) processor to compute an S-filter, which estimates a transfer function from an earpiece speaker, that is to be worn by a user, to an error microphone. The ANC processor adaptively produces an anti noise signal for reducing ambient noise that can be heard by the user. An adaptive equalization (EQ) processor has an EQ filter controller that adjusts an EQ filter, while audio user content is being filtered in accordance with the EQ filter before being fed to the speaker and then heard by the user. Other embodiments are also described and claimed.

Abstract: An accessory having an earbud for insertion into a user's ear is disclosed. The earbud may include a speaker and a microphone in which the speaker plays an audio signal for the user and the microphone receives the audio signal. The accessory includes a processor that is coupled to the speaker and the microphone to execute various operations. For example, the operations may include: determining a ratio of an energy estimation of the speaker audio signal to an energy estimation of the audio signal received by the microphone; determining a gain for the speaker audio signal based upon the ratio; based upon the gain, selecting a shelving filter; and applying the shelving filter to the speaker audio signal.

Abstract: In one aspect, multiple adaptive W filters and associated adaptive filter controllers are provided that use multiple reference microphone signals to produce multiple, “component” anti-noise signals. These are gain weighted and summed to produce a single anti-noise signal, which drives an earpiece speaker. The weighting changes based on computed measures of the coherence between content in each reference signal and content in an error signal. Other embodiments are also described and claimed.

Abstract: An active noise control (ANC) processor has an adaptive filter that uses a reference signal to produce an anti-noise signal, and an error signal to evaluate cancellation performance. An adaptive filter algorithm engine configures the filter coefficients of the adaptive filter, in accordance with pre-shaped versions of the error and reference signals. The pre-shaping filter has a high-pass transfer function and enables the adaptive algorithm engine to increase noise cancellation performance in a high frequency band during the presence of focused or narrow-band noise energy in a low frequency band. Other embodiments are also described and claimed.