Hi Ralf,
[rocketmouse@archlinux ~]$ beep -l300 -f750 --verbose --debug beep: Verbose: evdev: driver_detect 0x562c898210c0 (nil) beep: Verbose: lib: could not open(2) /dev/input/by-path/platform-pcspkr-event-spkr: Permission denied
As an aside, https://wiki.archlinux.org/title/PC_speaker#Installation says how to fix this.
[root@archlinux rocketmouse]# beep -l300 -f750 --verbose --debug beep: Verbose: evdev: driver_detect 0x5629ee7cd0c0 (nil) beep: Verbose: lib: opened /dev/input/by-path/platform-pcspkr-event-spkr as fd=3 beep: Verbose: main: using evdev driver (fd=3, dev=/dev/input/by-path/platform-pcspkr-event-spkr) beep: Verbose: main: 1 times 300 ms beeps (100 ms delay between, 0 ms delay after) @ 750 Hz beep: Verbose: evdev: driver_begin_tone 0x5629ee7cd0c0 750 beep: Verbose: evdev: driver_end_tone 0x5629ee7cd0c0 beep: Verbose: evdev: driver_end_tone 0x5629ee7cd0c0 beep: Verbose: evdev: driver_fini 0x5629ee7cd0c0
Is your sound system, e.g. ALSA, muting the speaker? See the above wiki link. -- Cheers, Ralph.