+.B speaker_backend \fINAME\fR
+Selects the backend use by the speaker process. The following options are
+available:
+.RS
+.TP
+.B alsa
+Use the ALSA API. This is only available on Linux systems, on which it is the
+default.
+.TP
+.B command
+Execute a command. This is the default if
+.B speaker_command
+is specified, or (currently) on non-Linux systems.
+.TP
+.B network
+Transmit audio over the network. This is the default if
+\fBbroadcast\fR is specified. You can use
+.BR disorder-playrtp (1)
+to receive and play the resulting stream on Linux and OS X.
+.RE
+.TP
+.B sox_generation \fB0\fR|\fB1
+Determines whether calls to \fBsox\fR(1) should use \fB-b\fR, \fB-x\fR, etc (if
+the generation is 0) or \fB-\fIbits\fR, \fB-L\fR etc (if it is 1). The default
+is 0.
+.TP
+.B speaker_command \fICOMMAND
+Causes the speaker subprocess to pipe audio data into shell command
+\fICOMMAND\fR, rather than writing to a local sound card. The sample format is
+determine by
+.B sample_format
+above.
+.IP
+Note that if the sample format is wrong then
+.BR sox (1)
+is invoked to translate it. If
+.B sox
+is not installed then this will not work.
+.TP