One consequence of that phenomenon is that in the suburbs of my city, you can‘t barely take a walk outside without getting annoyed by the high-pitch noisemakers that are installed in basically every garage and under most of the cars.
I'm confused by the noisemakers though?
Regarding noisemakers, I should rather say noise making devices, I guess. Here is a company promoting theirs (quick Google search): https://mardersicher.com/marderschreck-mardersicher-ms-12v-m... Googling for an example, I just discovered that the German Wikipedia has an extensive article (https://de.wikipedia.org/wiki/Marderabwehr) on defense mechanisms! The devices are supposed to only emit ultrasound. In practice, most don't.
I'm having trouble imagining them being frequent (and audible) enough to hear out on a walk though. Seems like an issue.