There is a valid question at the end that is not off topic,
[does] using a single image for several logos and icons … impact on the accessibility of the site
Whether you have single images and multiple HTTP requests or a single sprite image has zero affect on accessibility.
How you use the image (one or more) is what affects the accessibility.
Images used in the background (CSS
background: url (foo.jpg) with offsets) are invisible to screen readers, which is a good thing if the picture is decorative.
If a background image is informative and has a meaning, it should be passed on to all users. This is normally done with the
alt attribute on the
tag but if the image is in the background, then the image information must be on the HTML element containing (or one of its ancestors).
But this is starting to get into the implementation and should be addressed on stackoverflow.com. You can post and use the
accessibility tag as you did on this issue.
The simple answer to the gleaned question is "no".