Amazon POlly - Track must be 44.1 kHz

You can configure the sample rate, but the supported values depend on the format. Unfortunately none of the formats go as high as 44.1 kHz. From the API documentation:

The audio frequency specified in Hz.

The valid values for mp3 and ogg_vorbis are "8000", "16000", "22050", and "24000". The default value for standard voices is "22050". The default value for neural voices is "24000".

Valid values for pcm are "8000" and "16000" The default value is "16000".