When turning off your master volume, taking flight and turning the master value back on, the elytra flight sound will not start playing unless you land and take flight again.

How to reproduce:
1. Equip an elytra
2. Go to an elevated position so you can take flight

3. Turn master volume to 0%

4. Take flight

5. While flying, turn master volume back to 100% (or lower, as long as you can hear something)

6. Observe that there are no flying sounds