Vocalizer is a text to speech engine written by Nuance Communications, Inc. It is included as a standard TTS engine on iOS devices, and can be purchased for others such as the free NVDA screen reader. The speech quality is very natural, allowing for anyone to understand good quality speech at even high speeds. Several varients exist of one voice, ranging from compact to premium high. These offer a wide range of sizes – from 650 kilobytes to over 400 megabytes for the premium high voices. Please note that compact voices now work for this text to speech engine.
Source: Vocalizer TTS
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