gpt-4o-mini-tts - GPT-4o Mini TTS model"gpt-4o-mini-tts""The quick brown fox jumps over the lazy dog."alloy - Neutral, balanced voiceecho - Male, calm voicefable - British, narrative voiceonyx - Male, deep voicenova - Female, energetic voiceshimmer - Female, gentle voice"alloy"wav - WAV format, uncompressed (default)opus - Opus format, for internet streamingaac - AAC formatflac - FLAC format, lossless compressionpcm - PCM format, raw audio data"wav"0.25 - Slowest speed (1/4x)1.0 - Normal speed (default)4.0 - Fastest speed (4x)1.0