Parameter « -a / --audible-ping audible ping » no sound...

[Creteil]

Using the parameter doesn't output any sound...

bigbob@bigbob-t480s:~/tmp/Building/httping/httping$ ./build/httping http://127.0.0.1:24680 -a -c 3
PING 127.0.0.1:24680 (/):
connected to 127.0.0.1:24680 (314 bytes), seq=0 time=  0,55 ms 
connected to 127.0.0.1:24680 (314 bytes), seq=1 time=  0,79 ms 
connected to 127.0.0.1:24680 (314 bytes), seq=2 time=  1,17 ms 
--- http://127.0.0.1:24680/ ping statistics ---
3 connects, 3 ok, 0,00% failed, time 3003ms
round-trip min/avg/max = 0,5/0,8/1,2 ms
bigbob@bigbob-t480s:~/tmp/Building/httping/httping$

Is there any tip to be able to use it or did I miss something evident ?