Text to Speech (TTS) for Telephone Systems

Having been a provider of voice artist recordings to the telephony sector for over 25 years, we’ve long been monitoring TTS.  Our opinion of it has moved from laughter at obvious mispronunciations; to keeping a keen eye on it; to partnering with one of the world’s leading university faculties that focuses on TTS; to bringing TTS development in-house and embedding it within our PromptVoice Portal solution.  TTS is a key part of our strategy.   

These examples illustrate the current state of the art. 

Raw text to speech using one of the best British text to speech characters. 
 Human sounding, but some mispronunciations and rather flat read. 

Edited text to speech using speech synthesis mark-up language (SSML) and studio editing.  
□ Mispronunciations corrected and more emotion / expression added. 

On-brand real voice, studio produced.  
Choice of voices aligned with company audio brand guidelines. 

Does TTS have a place in telephony? 

Text to speech definitely has a place in telephony. The major advantage of TTS is that it is near instantaneous – so ideal for delivering instant recordings when speed is important. But the TTS engines, though human sounding, do not yet have the emotion and empathy a real voice can deliver.

The range of characters is currently also limited to a few for each language from each major TTS vendor. PromptVoice Portal offers the best of both worlds with its ‘Use a TTS recording until the real voice-over is available’ option, where a TTS recording is instantly available but is automatically replaced by the real human recording as soon as it is edited and quality checked.

Which text to speech vendor is best? 

We are often asked, “Which TTS engine is better, Amazon Polly, Google, IBM or Microsoft?”.  The answer is that it is different for different languages and dialects.   

The quality of the TTS is dependent on the engine and the input recordings used to create the TTS character.  The best male Irish TTS character may be produced by a different manufacturer from the best female Irish character.  Ultimately there is no global ‘best’ even for a particular gender/language, as it depends what persona you're looking for.   

With all major TTS engines included in PromptVoice Portal, we offer customers the ability to compare the best of breed TTS characters within the portal to find the one that best matches the tone of voice they are seeking.






Our Voice Guarantee promises that if your chosen voice becomes unavailable, we will re-record every message we've done for you with a new voice, absolutely free – ensuring complete consistency across your telephone systems. Our guarantee can be extended at any stage by purchasing more credit. Subject to terms and conditions.