Why "Hibiki"? There is a scroll in Endo shihan's dojo that means, "Path of the mountain echo". And when I asked him to name this new dojo, he said this phrase but something longer, and we decided it would be best to make the name shorter and decided on just "Hibiki".
In one sense, we do aikido to learn how to be nothing, to get out of the way and let things, including ourselves, just be "as is". A mountain echo is simply the sound of your voice echoed back to you. Nothing is really added or changed.
In another sense, we practice aikido to understand that what we send out into the world reflects back to us.
We practice to quiet our mind. If we can be quiet, we can sense our own and our partner's natural "vibration" without interfering, without modifying or corrupting, and just "hear".
And in aikido we strive to match our energy with the other person. This means we not only have to sense their vibration but also be able to vibrate with them and sync up with them - this requires being able to do action in a way that isn't forcing or overpowering yet not passive or disengaged. This is why we practice softly, supply, and without strength.
Check Your Goals For Observing