Can an ultrasonic communication provide helpful connectivity to Voice Interface and IoT devices, without facilitating intrusive data mining?

Ultrasonic communication, and in particular, near-ultrasonic communication has for the most part been an untapped resource in the voice interface and IoT worlds. It has been described by Wired as the “wild west of wireless tech”, in an article which explores the possible privacy and security risks with the technology:

https://www.wired.com/story/ultrasonic-signals-wild-west-of-wireless-tech/

There are many reasons why it is appealing as a protocol:

• Alternative communication method to WiFi or BLE, where they are either not optimal on unavailable
• Voice Interface devices already have necessary hardware (a microphone and a speaker)
• Allows cross platform sharing of information
• Proximity verification of a user

There are also reasons why it is concerning as a protocol:

• Unauthorized tracking of individuals movements or habits
• Ultrasonic attacks
• Spamming the audio spectrum
• Considerations beyond humans – dogs, other ultrasonic sensitive animals

Some companies such as Google, have their own internal protocol like Google Nearby which has a fully secured end to end solution which works in conjunction with WiFi and BLE. Other companies like Chirp provide secure encryption protocols to allow ultrasonic data exchange to operate independently.

From an acoustics point of view, is it possible to implement sufficient protocols in an ultrasonic transmission standard so it is used for useful connectivity?

• Standard transmission levels so devices have to be within a certain range?
• Individual transmission bursts rather than constant beacons?
• Use of constantly varied frequencies to avoid potential interference?