An old chestnut I know, but I can't hear the modem dialling the ISP, but it connects OK so there aren't any problems with it.
In device manager the modem speaker volume is set to max and direct x sound is enabled, but I seem to remember something about an AT command in the modem dialling string that turned the sound on or off - can't for the life of me remember what it is or where to find it.
In Control Panel, Phone/Modem, select your modem and look at Properties. Select Modem, Properties, Advanced and then look at Extra Settings. If you see atm0 in the text box, try removing this as this setting keeps the modem quiet when dialling. I think the defaul is atx0. Worth a try.
I want to switch the audio on because I'm setting it up for someone who is very new to computers and the internet - the dialling noises are a psychological assurance that something is happening.
I've gone into control panel and modem properties, dialling properties,etc ,etc, but there's no extra settings option under the advanced tab. The machine is using Win98SE with a motorola sm56 internal modem