On FreeBSD /dev/dsp is the default device but may not be /dev/dsp0.
PortAudio in the FreeBSD ports collection initially had a patch to
replace the default device with /dev/dsp (for example, with three
devices and /dev/dsp1 as the default we'd have /dev/dsp0, /dev/dsp,
/dev/dsp2). This caused some trouble (the first device is no longer
default) and was later replaced with this change, leaving /dev/dsp
as the first entry, and just adding each /dev/dsp%d that exists.
FreeBSD bugs 208968 and 236118.
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