Although there can be a number of reasons for failure to establish a modem connection, I was a troubled by the unusual tones I heard through the modem. The first step in troubleshooting modems is simply to try calling again. If that doesn't work, move on to the universal first steps you should take when facing any computer problem. First, if you have an external modem, simply turn the modem off and on. For whatever reason, turning a modem off and on usually takes care of many problems.
Many people have internal modems.
The second universal step is to reboot your computer or turn the computer itself off and on. If that doesn't solve the problem, check your physical connections from cables to phone jack. You especially want to do this if the modem does not get a dial tone or dial the outside number. A loose cord or connection could be your problem. Finally, re-connect your modem to a different phone jack and try it again.