You would need to edit the SVG codes to do that, BUT instead of adding an aria-label
you can include a <title>
element inside your SVG code.
For example, this is the opening part of the SVG code:
<svg xml:space="preserve" style="enable-background:new 0 0 1349.6 371.8;" viewBox="0 0 1349.6 371.8" y="0px" x="0px" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" id="Ebene_1" version="1.1">
Immediately after its closing >
you can add:
<title>your SVG title</title>
This title will be read Assistive Technologies