it looks like your audio devices are all at 48khz but your audio settings tab in obs had it at 44.1khz. change audio setting in the "Audio" tab to 48khz so OBS won't have to resample it which may cause distortion. Otherwise, under "output"
phoodle you can try setting your audio bitrate higher, or download CoreAudio codec (tutorial:
here)
otherwise, the distortion may be your microphone itself.