Hi I'm currently using mod_tts_commandline with a python script to AWS text to speech API. The flow works fine during a single call. Event socket API -> Freeswitch dialplan -> mod_tts_commandline -> Python script -> AWS API -> Voice file -> Freeswitch say However when there a number of concurrent calls (even just 10 to 15) the request to execute the python script hangs until all the calls are at the same requesting state. As if mod_tts_commandline is waiting for something to happen. Dial plan: <extension name="tts_google"> <condition field="destination_number" expression="^11111$"> <action application="set" data="call_timeout=60" /> <action application="answer"/> <action application="detect_silence" data="100 30 25000"/> <action application="speak" data="tts_commandline|${lang}|${text}" /> <action application="hangup"/> </condition> </extension> tts_commandline.conf: <param name="command" value="/usr/bin/python /usr/local/freeswitch/scripts/synthesize_text.py --language=${voice} --filename=${file} --text=${text}"/> </settings> Execution of python script in freeswitch logs: 2018-08-30 11:19:57.641892 [ERR] switch_ivr_play_say.c:2385 switch_ivr_detect_silence: SILENCE DETECTED 2018-08-30 11:19:57.641892 [DEBUG] switch_core_codec.c:248 sofia/external/33123456789 Restore previous codec PCMU:0. EXECUTE sofia/external/33123456789 speak(tts_commandline|en-US|Hi, This is a test message) 2018-08-30 11:19:57.641892 [DEBUG] switch_ivr_play_say.c:3025 OPEN TTS tts_commandline 2018-08-30 11:19:57.641892 [DEBUG] switch_ivr_play_say.c:3035 Raw Codec Activated 2018-08-30 11:19:57.641892 [DEBUG] mod_tts_commandline.c:160 Executing: /usr/bin/python /usr/local/freeswitch/scripts/synthesize_text.py --language='en-US' --filename='/tmp/92ec5996-0dc8-4293-b5ba-465430811fed.tmp.wav' --text='Hi, This is a test message' "Simultaneous calls requesting mod_tts_commandline" Log from python script: (notice it's called with a 15 second delay) ---> *What is causing this delay?* 2018-08-30 11:20:12,488 DEBUG Called script 2018-08-30 11:20:12,490 DEBUG Arguments Namespace(filename='/tmp/92ec5996-0dc8-4293-b5ba-465430811fed.tmp.wav', language='en-US', ssml=None, text='Hi, This is a test message') 2018-08-30 11:20:12,490 DEBUG synthesize_text requested The python script executes fine and returns to freeswitch: 2018-08-30 11:20:14.541919 [DEBUG] switch_core_file.c:342 File /tmp/c61d2034-c1b1-4f42-932f-350484553b5a.tmp.wav sample rate 24000 doesn't match requested rate 8000 2018-08-30 11:20:14.541919 [DEBUG] switch_ivr_play_say.c:2729 Speaking text: Hi, This is a test message Any help or further debugging steps would be appreciated. Thanks Lee