(18.04) Recording-Problems with my USB-Microphone

The problem is same ancient as Ubuntu. It has the name "Logitech webcam microphone chipmunk sound". Looks like the problem has resurrected with Ubuntu 18.04 with its 4.15 kernel.

The well-known old workaround for the bug "Logitech camera microphone makes "chipmunk" sound" has worked for my Logitech C270 webcam like a charm.

You have to disable USB autosuspend at kernel boot parameters. Open /etc/default/grub file with a text editor, let it be nano for instance:

sudo nano /etc/default/grub

and find there line with GRUB_CMDLINE_LINUX_DEFAULT. Add usbcore.autosuspend=-1 to kernel parameters, i.e. replace the line

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

with this one

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.autosuspend=-1"

Save changes and apply it to your system with grub update:

sudo update-grub

Reboot your computer and the chipmunk (Mickey Mouse) sound problem has to dissappear.

Doing this worked for me:

mkdir $HOME/.pulse/
echo "default-sample-rate = 16000" >> $HOME/.pulse/daemon.conf
pulseaudio --kill && pulseaudio --start

Then I also restarted computer.

Reference: Logitech C310 audio problems