In typical active noise-canceling systems including noise-canceling circuitry powered by a battery, when the battery has a low charge, the audio output can become distorted or absent. The existing art addresses this problem in several ways.
To avoid the distortion from the noise-canceling circuitry, a user can either provide more power, such as by removing and replacing or otherwise changing the battery or plugging the active noise-canceling system into another power supply. Other systems include a switch coupled to the noise-cancelation circuitry that the user can physically toggle to divert the audio path around the noise-canceling circuitry. One existing solution requires the user to disconnect the battery from the noise-canceling circuitry. However, each of these solutions requires physical interaction from a user and can interrupt audio output or other interaction between a headset and the user.
In another example, a wireless headset can include a digital signal processor configured to monitor battery conditions and ambient noise levels and to turn off part of or all noise-canceling circuitry in the wireless headset in response to low levels of detected ambient noise or in response to low battery conditions. However, this solution requires that a wireless headset include a digital signal processor for implementation, and, as such, when the battery level drops below a required threshold for operation of the digital signal processor, this solution fails, as the wireless headset can no longer communicates with any other electronic device.