Proximity discovery using audio signals

A computing system comprising:

• at least one processor;
• and
• memory that comprises instructions that, when executed by the at least one processor, cause the at least one processor to perform acts comprising:
• comparing an audio-based signature of surroundings of a client computing device with an audio-based profile of a room, the audio-based signature is based upon a high frequency portion of an audio signal captured by the client computing device, the audio-based profile is based upon high frequency portions of other audio signals captured by other client computing devices when the other client computing devices were previously in the room, wherein the high frequency portion of the audio signal and the high frequency portions of the other audio signals being frequencies in the audio signal above 18 KHz;
• determining that the client computing device is located in the room based upon the comparing of the audio based signature with the audio-based profile of the room;
• and
• responsive to determining that the client computing device is located in the room, providing the client computing device with an indication that the client computing device is in the room.