The only way I know to check this, is to compile the different sound drivers into the kernel and check whether they are detected or not. The best way to do so, is to compile them as modules because it's easier to load different parameters such as interrupts and IO ports this way. For the 2.2.x kernels, read /usr/src/linux/Documentation/sound/Introduction by Wade Hampton. This document may help you get started with sound. Also, you might try one of the commercial sound drivers mentionend below. To check whether sound works or not you may try e.g. xmms and one of the sounds provided in /usr/share/sounds.
ALSA Advanced Linux Sound Architecture . The Advanced Linux Sound Architecture aims to: be a fully-modularized sound driver which supports kerneld/kmod, ensure compatibility with most binary OSS/Lite applications, create an ALSA Library (C,C++) which covers the ALSA Kernel API for applications, and create ALSA Manager, an interactive configuration program for the driver. With Kernel 2.6 these modules will be part of the Linux Kernel.
UNIX Sound System Lite / OSS provides commercial sound card drivers for most popular sound cards under Linux. These drivers support digital audio, MIDI, Synthesizers and mixers found on sound cards. These sound drivers comply with the Open Sound System API specification. OSS provides a user-friendly GUI which makes the installation of sound drivers and configuration of sound cards very simple. OSS supports over 200 brand name sound cards. OSS drivers provide automatic sound card detection, Plug-n-Play support, support for PCI audio soundcards and support.
As a last resort you may try the speaker module pcsnd, which tries to emulate a soundcard.
VXPocket looks like a finally medium2high-end soundcard solution for onboardwise badly equipped laptops. Note: I didn't check whether this is a PCMCIA card or not. PCMCIA sound cards are probably not supported.
Also USB may be an alternative. Most USB audio devices are supported by recent kernels. An example is Labtec Axis 712 Stereo Headset (headphones and microphone) which works in full-duplex mode. For more info about this and other Linux-compatible USB audio devices see the USB Survey and my Mobile USB Linux Hardware Survey .
For playing CDs/DVDs from an external or internal CD/DVD drive, see chapter Section 12.32 CD/DVD Drive below.