Abstract: Aspects of the subject technology provide for, while attenuating noise from a physical environment at a first device, for example, by active noise cancellation, outputting, by the first device, an audio signal for detection by a user. Aspects of the subject technology also provide, by the first device and to a second device, an indication of an estimated noise level of the attenuated noise at the first device for storage in association with an indication of whether the audio signal was detected by the user.

Abstract: Aspects of the subject technology provide for calibration of audio devices in a case. In some implementations, the calibration techniques may include detecting that an audio device is docked in a case and a lid of the case is in a closed position, where the audio device is positioned in a cavity of the case. In addition, the calibration techniques may include emitting a test audio signal from a speaker of the audio device into the case. The device may include receiving, in response to the test audio signal, a received signal at a sensor inside the case. Moreover, the device may include obtaining a correction for the audio device based on the received signal.