RE: https://mastodonapp.uk/@ianvisits/116675450497287566
“ Through acoustic testing, the research team at Salford identified a narrow frequency band, or “safety gap”, of between 750Hz and 780Hz that consistently penetrates ANC filters. By combining this with a second resonator tuned to a higher frequency, and a specially designed striking mechanism that produces rapid, irregular impacts, the bell generates sound waves that ANC algorithms cannot calculate quickly enough to cancel.”






