alsa software package provides virtual package provided by alsa-base-udeb, alsa-base, you can install in your Debian 7 (Wheezy) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install alsa
alsa is installed in your system.
Make ensure the alsa package were installed using the commands given below,
$ sudo dpkg-query -l | grep alsa*
You will get with alsa package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | Virtual packages |
| Package | alsa |
| Version | |
| Description | virtual package provided by alsa-base-udeb, alsa-base |
| Sub Section | virtual |