Imbuing machines with the ability to talk has been a longtime pursuit of
artificial intelligence (AI) research. From the very beginning, the community
has not only aimed to synthesise high-fidelity speech that accurately conveys
the semantic meaning of an utterance, but also to colour it with inflections
that cover the same range of affective expressions that humans are capable of.
After many years of research, it appears that we are on the cusp of achieving
this when it comes to single, isolated utterances. This unveils an abundance of
potential avenues to explore when it comes to combining these single utterances
with the aim of synthesising more complex, longer-term behaviours. In the
present chapter, we outline the methodological advances that brought us so far
and sketch out the ongoing efforts to reach that coveted next level of
artificial expressivity. We also discuss the societal implications coupled with
rapidly advancing expressive speech synthesis (ESS) technology and highlight
ways to mitigate those risks and ensure the alignment of ESS capabilities with
ethical norms.

将机器赋予说话的能力一直是人工智能研究的长期追求。通过对语义意义和情感表达范围进行准确合成，我们正处在实现这一目标的边缘。本文概述了让我们取得如此成果的方法学进展，并勾勒了达到人工表达能力的下一个层次的不断努力。同时，我们还探讨了快速发展的表达性语音合成（ESS）技术的社会影响以及降低风险和确保 ESS 能力与道德规范对齐的方法。