An urban air mobility (UAM) noise reduction system and method are provided, where the UAM noise reduction system includes a UAM configured to detect and to provide rotation per minute (RPM) information of a propeller and location coordinate information, and a noise canceling device configured to predict a noise canceling sound wave amplitude on the basis of the RPM information of the propeller and the location coordinate information received through the UAM and to output a noise canceling sound wave corresponding to the predicted noise canceling sound wave amplitude to the UAM.

A signal processing device according to an embodiment includes: two or more microphones each provided with a sound collection unit directed to an outside of a housing including a driver unit, a control unit (102b) that performs a hearing control of sound output from the driver unit to a listener based on sound signals collected and output by the two or more microphones, and an adjustment unit (200) that adjusts a degree of the hearing control between a degree for wind and a degree for non-wind based on a correlation between the sound signals.

A method and apparatus are for determining one or more background noise characteristics, determining one or more incoming audio characteristics; and generating a combined audio signal comprising an active noise cancellation (ANC) component and a modified incoming audio (MIA) component. The ANC component is determined based on at least one of the one or more incoming audio characteristics and the background noise characteristics. Each of a limit of the ANC component and a limit of the MIA component is dynamically controlled to be less than or equal to a system limit, wherein a limit of the combined signal is approximately at the system limit

Provided are methods and apparatus for enhancing a signal-to-noise ratio. In an example, provided is an apparatus configured to modify audio to better match the way the human brain processes audio by modifying the audio to a form which takes advantage of human echolocation capabilities. When humans listen to audio, they subconsciously listen for an echo and thus subconsciously focus on listening to, and for, meaningful information in audio. The focus causes humans to ignore noise in the audio, which results in enhancing a signal-to-noise ratio.

Various implementations include systems for providing enhanced aware mode capabilities in an ANR audio device. In particular implementations, a method includes receiving an ambient noise signal from a microphone associated with a wearable audio device; determining a gain value based on a sound pressure level (SPL) of the ambient noise signal; generating a gain adjusted ambient noise signal by applying the gain value to the ambient noise signal; generating a total external microphone signal by adding the gain adjusted ambient noise signal to a noise reducing ambient signal; generating an expanded audio signal by selectively adjusting a source audio signal based on the gain adjusted ambient noise signal; and combining and outputting the expanded audio signal with the total external microphone signal to an acoustic transducer.

According to an aspect, an active noise control device includes: a control frequency determinator that determines a frequency of the noise; a reference cosine-wave generator that generates a reference cosine-wave signal having the determined frequency; a reference sine-wave generator that generates a reference sine-wave signal having the frequency of a noise; a first one-tap adaptive filter to which the reference cosine-wave signal is input, the first one-tap adaptive filter having a first filter coefficient; a second one-tap adaptive filter to which the reference sine-wave signal is input, the second one-tap adaptive filter having a second filter coefficient; an adder that adds an output signal from the first one-tap adaptive filter and an output signal from the second one-tap adaptive filter to each other; a secondary noise generator that is driven by an output signal from the adder to generate a secondary noise; a residual sound detector that detects a residual sound generated by interference between the secondary noise and the noise; a simulation signal generator that outputs a simulation cosine-wave signal and a simulation sine-wave signal, the simulation cosine-wave signal and the simulation sine-wave signal being obtained by correcting the reference cosine-wave signal and the reference sine-wave signal using a characteristic in which a transfer characteristic from the secondary noise generator to the residual sound detector is simulated; and a filter coefficient updating unit that updates the first filter coefficient and the second filter coefficient based on an output signal from the residual sound detector, an output signal from the simulation signal generator, the reference cosine-wave signal, the reference sine-wave signal, and the output signal from the adder. The secondary noise is reduced in a space where the residual sound detector is installed.

An active noise control arrangement has a signal input (SI), a microphone input (MI), a signal output (SO) and a digital interface (DI). A signal processing block (SP) coupled to the microphone input (MI) by means of an amplifier (MA) has a digitally adjustable gain and comprises combining means (CM) and a filter (TP). The signal processing block (SP) is configured to generate an output signal at the signal output (SO) as a function of an input signal at the signal input (SI) and an amplified microphone signal. A control block (CB) is coupled to the digital interface (DI) and configured to adjust the gain of the amplifier (MA).

An audio system attachable to a computer includes a sound reproduction device for producing audible sound from audio signals. The sound reproduction device includes a radio tuner and a powered speaker. The audio system further includes a connector for connecting the sound reproduction device with a computer. The computer provides audio signals from a plurality of sources, the sources including a computer CD player, digitally encoded computer files stored on the computer, and a computer network connected to the computer. The sound reproduction device further includes control buttons for controlling at least one of the computer CD player, the digitally encoded computer files and the computer network.

An active noise control device controls a speaker so as to output a canceling sound for canceling noise transmitted from a vibration source. The active noise control device includes a control signal generating unit configured to perform signal processing on a basic signal corresponding to a predetermined frequency by a feedback filter and a extraction filter, which is an adaptive notch filter, to generate a control signal that control the speaker, a secondary path filter updating unit configured to update sequentially and adaptively a secondary path filter, and a feedback filter setting unit configured to set the feedback filter based on the secondary path filter.

An apparatus for realizing an active noise cancellation control law transfer function between a sensing microphone and a speaker. The apparatus includes a multiplicity of filters. Each filter is operable over a different frequency range. At least one filter has an adjustable parameter whereby the filter can be adjusted such that the filters cumulatively realize a required control law transfer function. The adjustable parameter may in one embodiment be the amplitude. In other embodiments, it may be other parameters.