No, not at all. Infact there are no APIs at all!
Integrating voice in any application was problematic and complex for various issues - from the
painful days of using telephony cards, proprietary drivers to the most recent wherein few companies
came out with APIs. Some of these companies provided APIs which couldn't cater to complex requirements
and were merely usable for basic voice and telephony functionality.
TringMe was amongst the very few who provided powerful REST and Flash API for tight integration with applications.
VoiceXML is another solution but it has its own limitations.
VoicePHP goes well beyond the API paradigm and integrates voice into the language itself. Apart from programming
in a familiar language (i.e. PHP), one continues to use the same development and testing tools.
There is no need to invoke special “vendor-specific” APIs