--- espeak-1.48.04-source/src/Makefile
+++ espeak-1.48.04-source/src/Makefile
@@ -43,6 +43,11 @@ WAVE=wave_pulse.cpp
 LIB_AUDIO=-lpulse
 USE_AUDIO=-DUSE_PULSEAUDIO
 else
+ifeq ($(AUDIO),ao)
+WAVE=wave_ao.cpp
+LIB_AUDIO=-lao
+USE_AUDIO=-DUSE_AO
+else
 ifeq ($(AUDIO),portaudio)
 WAVE=wave.cpp
 LIB_AUDIO=-lportaudio
@@ -69,6 +74,7 @@ endif
 endif
 endif
 endif
+endif
 
 speak_SOURCES = speak.cpp compiledict.cpp dictionary.cpp intonation.cpp \
 	readclause.cpp setlengths.cpp numbers.cpp synth_mbrola.cpp \