This is the one thing I dislike about Apple Airpods. I also don't like the connection sound effect because it adds a needless 2 second delay. Would love to get rid of both sound effects.
Likely the delay is not because of the sound effect. But the other way around - they added the jingle to mask the delay.
I wish I had such faith.
Bluetooth link negotiation happens in a few dozens of milliseconds. Any perceptible delay is down to the host operating system setting up audio drivers. The headset can't know what the host is doing or even that there is a delay.
You can change the volume of those sounds under Settings > AirPods > Accessibility.