My laptop speakers are producing a tapping sound which occurs every ~2seconds and only when there is not other audio playing. When I connect external speakers the tapping is even loder (and still coming from internal speakers). I remember this wasn't happening a while ago.
I have made a recording of it - SoundCloud stream.
lshw produces this output concerning audio:
*-multimedia description: Audio device product: SBx00 Azalia (Intel HDA) vendor: Hynix Semiconductor (Hyundai Electronics) physical id: 14.2 bus info: pci@0000:00:14.2 version: 00 width: 64 bits clock: 33MHz capabilities: bus_master cap_list configuration: driver=snd_hda_intel latency=64 resources: irq:16 memory:fbaf4000-fbaf7fff
What can I do to eliminate this sound?