  Although audio generation shares commonalities across different types of
audio, such as speech, music, and sound effects, designing models for each type
requires careful consideration of specific objectives and biases that can
significantly differ from those of other types. To bring us closer to a unified
perspective of audio generation, this paper proposes a framework that utilizes
the same learning method for speech, music, and sound effect generation. Our
framework introduces a general representation of audio, called "language of
audio" (LOA). Any audio can be translated into LOA based on AudioMAE, a
self-supervised pre-trained representation learning model. In the generation
process, we translate any modalities into LOA by using a GPT-2 model, and we
perform self-supervised audio generation learning with a latent diffusion model
conditioned on LOA. The proposed framework naturally brings advantages such as
in-context learning abilities and reusable self-supervised pretrained AudioMAE
and latent diffusion models. Experiments on the major benchmarks of
text-to-audio, text-to-music, and text-to-speech demonstrate state-of-the-art
or competitive performance against previous approaches. Our code, pretrained
model, and demo are available at https://audioldm.github.io/audioldm2.
