To enabling and disabling the Speakers & Microphones via HTTP API:
<Camera-IP>/admin/audio?AUDIO_IN=0&save_config (Disable Mircophone)
<Camera-IP>/admin/audio?AUDIO_IN=2&save_config (Enable Microphone)
<Camera-IP>/admin/audio?SPEAKER=0&save_config (Disable Speaker)
<Camera-IP>/admin/audio?SPEAKER=2&save_config (Enable Speaker)
<Camera-IP>/admin/audio?AUDIO_IN=0&SPEAKER=0&save_config (Disable both Speaker and Microphone)
The list below gives the numerical values you can use within this API command, depending on what you need to enable
SPEAKER
0 = off
2 = internal speaker (on S14/15/16 internal line out)
3 = ExtIO/CamIO speaker
5 = ExtIO line out
MICRO
0 = off
2 = internal microphone
3 = ExtIO microphone
5 = ExtIO line in
6 = microphone cam 0 (S14/15/16)
7 = microphone cam 1
8 = microphones of both cams
9 = line in S14/15 board