Abstract: A first computing device is configured to broadcast a first audio token comprising a first identifier over a first audio frequency channel, activate a first microphone component, and receive a first audio response token generated by a second computing device via the first audio frequency channel. A second computing device is configured to receive an input indicating a request to receive data, activate the second microphone component, receive the first audio token over the first audio frequency channel, receive one or more other audio tokens over one or more other audio frequency channels, determine that the received first audio token comprises a valid audio token, restrict the range of received audio inputs to comprise only the first audio frequency channel, generate the first audio response token, and communicate the first audio response token to the first computing device via the first audio frequency channel.