Companies are using ultrasound audio signals to track the devices of consumers. The high-frequency sound is undetectable to the human ear but can be heard by microphones in technology such as phones and tablets, with companies then capable of working out where an individual has been, which adverts they've seen or what web pages they've visited. A study published last year found that a single device could identify up to 80% of people within 100 metres of it.
Companies are using ultrasound audio signals to track the devices of consumers. The high-frequency sound is undetectable to the human ear but can be heard by microphones in technology such as phones and tablets, with companies then capable of working out where an individual has been, which adverts they've seen or what web pages they've visited. While many users will grant access to their microphone thinking it only applies when using a specific app, companies often then continue to use ultrasound tracking continuously to gather data.