A signal processing method includes: receiving, by a signal input, a digital input signal from a device under test; capturing, by a measurement circuit, at least one IQ measurement set based on the received input signal, wherein the at least one IQ measurement set comprises a plurality of IQ measurement points; determining, by an analysis circuit, a total noise of the digital input signal over frequency based on the at least one IQ measurement set; determining, by the analysis circuit, an instrument noise over frequency, wherein the instrument noise corresponds to noise generated by the measurement instrument; and determining, by the analysis circuit, a ratio of the instrument noise and the total noise over frequency, thereby obtaining a frequency-dependent scaling factor. Further, a measurement instrument is described.

Disclosed is a noise reduction earphone including a memory, a speaker, a feedback microphone and a processor. The memory stores a target frequency response curve and a target frequency response difference corresponding to a sound signal. The feedback microphone collects a feedback signal corresponding to the sound signal. The processor receives a start signal and then performs a calibration process including (a) controlling the speaker to play the sound signal; (b) receiving the feedback signal; (c) generating a feedback frequency response curve based on the feedback signal, and obtaining a feedback frequency response difference between the target frequency response curve and the feedback frequency response curve; (d) adjusting a low-frequency gain of the feedback microphone when the feedback frequency response difference is less than or greater than the target frequency response difference, and returning to (a) until the feedback frequency response difference is equal to the target frequency response difference.

Various embodiments disclose a computer-implemented method that can include driving an audio output device to reproduce a stimulus signal when a wearable device is placed along an ear canal of a user, receiving a sound signal from a microphone based on the stimulus signal, and determining, based on the sound signal and a calculated response of the microphone retrieved from a memory, one or more characteristics of the ear canal of the user, wherein the one or more characteristics of the ear canal comprises an ear canal impedance, and applying, based on the one or more characteristics of the ear canal, an ear canal response correction to an output signal played back by the audio output device.

This disclosure relates to improved techniques for electronic noise cancellation in aircraft and other enclosures. In certain embodiments, an electronic noise cancellation device can be installed in an aircraft. In certain embodiments, the electronic noise cancellation device can include a housing that integrates: one or more audio input devices that are configured to receive an input audio signal; one or more audio output devices configured to output a noise cancellation signal; one or more lighting components; and at least one connector that enables the electronic noise cancellation device to be coupled to an overhead service component of the aircraft. In certain embodiments, the electronic noise cancellation device is adapted to be received in a lighting socket of the overhead service component included within an aircraft enclosure. Other embodiments are disclosed.