I know someone who uses tones as an easy way of knowing if there's a market move on some cryptocurrencies. Basically, there's different tones for a trade that traded higher than previous and for a trade that traded lower than the previous. Possibly pitch or volume or something was used to indicate the volume of the trade, I don't quite remember. Either way, he could quickly hear if there was a major market move or something just by the amount and tone of the beeps. He used this as a way to know then he should look at the chart or whatever.