I see. So the large supply voltage allows for higher gains without the distortion. Thanks for the help!You can get as much gain as you want with ANY supply voltage. But the circuit has only a single transistor so if the gain is high then the distortion will also be high.
You need a higher supply voltage so that loud voices or music will play loudly without distortion.
You never said what "sounds" you are sensing. Maybe nearby gun shots?? Then distortion does not matter.