The technology disclosed herein enables ambient noise level determination at an endpoint using a secondary audio capture system for the endpoint. In a particular embodiment, a method includes during a communication session, receiving an audio signal representing sound captured by a secondary audio capture system for an endpoint on the communication session. A primary audio capture system for the endpoint captures voice communications from a user of the endpoint for the communication session. The method further determining an ambient noise level for the endpoint from the audio signal and, in response to determining that the ambient noise level satisfies a loudness criterion, presenting a notification to the user about the ambient noise level.