Bluetooth sound distorted / crackling on Ubuntu 22.04 / Atheros 3K

I've just installed Lubuntu 22.04 (based on Ubuntu 22.04) on Acer E1-572P laptop with Atheros AR3012 bluetooth hardware. The bluetooth works fine for Spotify and other music streaming apps, but when I use it for Skype the received sound becomes distorted and crackles, a bit like something in the audio path is being overloaded in some way. The receive microphone works fine. When the bluetooth is disconnected and the on-board audio is used, the problem goes away.

I've tried reloading the bluetooth module, rebooting the system and several bluetooth devices.

Output of sudo dmesg | grep Blue:

[   10.538692] Bluetooth: Core ver 2.22[   10.538725] Bluetooth: HCI device and connection manager initialized[   10.538731] Bluetooth: HCI socket layer initialized[   10.538736] Bluetooth: L2CAP socket layer initialized[   10.538743] Bluetooth: SCO socket layer initialized[   15.243055] Bluetooth: BNEP (Ethernet Emulation) ver 1.3[   15.243060] Bluetooth: BNEP filters: protocol multicast[   15.243065] Bluetooth: BNEP socket layer initialized[   16.463796] Bluetooth: MGMT ver 1.22[   16.497575] Bluetooth: RFCOMM TTY layer initialized[   16.497583] Bluetooth: RFCOMM socket layer initialized[   16.497589] Bluetooth: RFCOMM ver 1.11

Output of sudo lsusb | grep Blu:

Bus 002 Device 006: ID 04ca:300b Lite-On Technology Corp. Atheros AR3012 Bluetooth

Output of lsb_release -a:

No LSB modules are available.Distributor ID: UbuntuDescription:    Ubuntu 22.04.4 LTSRelease:        22.04Codename:       jammy

Output of uname -r:

6.5.0-21-generic

Output of modinfo ath3k:

filename:       /lib/modules/6.5.0-21-generic/kernel/drivers/bluetooth/ath3k.kofirmware:       ath3k-1.fwlicense:        GPLversion:        1.0description:    Atheros AR30xx firmware driverauthor:         Atheros Communicationssrcversion:     A6C59810234C24ABA01660F [output shortened]depends:        bluetoothretpoline:      Yintree:         Yname:           ath3kvermagic:       6.5.0-21-generic SMP preempt mod_unload modversions 

Output of rfkill:

ID TYPE      DEVICE              SOFT      HARD 0 wlan      acer-wireless  unblocked unblocked 1 bluetooth acer-bluetooth unblocked unblocked 2 wlan      phy0           unblocked unblocked 3 bluetooth hci0           unblocked unblocked