When user clicks the application icon in the Web ICA link, at the application startup, startup audio tone may came up. It may be desired or user may not want it. Some applications have built in functionality based on audio.
Audio can be enabled or disable either during the application publishing or through the policies.
During application publishing, it can be enabled or disabled using Advanced > Client options as shown below:
Recommended way is to use farm policies as it would be the central place to maintain it.
Enabling or Disabling Audio can be evaluated based on the bandwidth and the application requirement. If we have high bandwidth, we can enable it but if we have limited or low bandwidth we can disable it or enable it with limited bandwidth assigned for it based on the application requirement. This can also be done using the policies [Bandwidth > Session Limits > Audio] as shown below:
Remember this could one of the important parameter to be evaluated for the efficient application delivery in XenApp.