Help! Zello somehow messed up my noiselevels!

Hallo everyone I wanted to test if I could use zello with my headphones. It worked fine. I pressed the speaker button. Noise out put got switched from headphones to loudspeaker. Somehow that messed up the noise controls. No matter waht I tried with switching speaker on and off. Closing zello with of without the headphones. As long as the headphones are put in things are fine. Otherwise the usual alerts and warning sounds are really quit turning up the percents doesn't help. On the other hand voiceover is really loud the voice itself and the tones that belong with it. When i switch voiceover off and on again the noise level is at 75%. When I turn it down it gets quiter but even at 1% I understand it just fine. Is it possible that I messed things somehow up by pressing some strange button combination on the headset? I don't know what else I can do and it gets annoying really fast. thanks for tips, Guenni