Here's a compilation I made of every major modem standard used in North America (Bell 103, V.22(bis), V.32(bis), V.34, V.90, and V.92), corresponding to 300 bps, 2400 bps, 14.4K, 33.6K, and 56K. Those of you who actually used the older (pre-V.34) standards might notice some slight differences in the sounds (with respect to timing) - this is because these were all made with a ~2005 embedded Conexan