Would you like to put flaps on your can?
Then.... https://www.wunderlich.de/shop/en/wunderlich-brands/gonzzoo.html
Then.... https://www.wunderlich.de/shop/en/wunderlich-brands/gonzzoo.html
If you suffer from a droning problem whilst riding, try turning the intercom off.
And many people ( including many of my f(r)iends have a habit of turning their bikes from beautiful quiet machines into noisy abortions. There is no accounting for taste.:
Sometimes the Germans have a tendency to make improvements no-one needs or have ever asked for.