There are a few different factors to consider when determining the recommended loudness settings for audio sampling:
The intended use of the audio: Different applications may have different loudness requirements. For example, music for streaming services generally has a target loudness of around -14 LUFS (Loudness Units Full Scale), while music for broadcast television may have a target loudness of around -24 LUFS.
The format of the audio: Different audio formats may have different loudness standards. For example, CD audio has a maximum peak level of 0 dBFS (Decibels Full Scale), while digital audio for streaming services may have a maximum peak level of -1 dBFS to ensure adequate headroom for loudness normalization.
The dynamic range of the audio: The dynamic range of an audio signal refers to the difference between the loudest and quietest parts of the audio. A wider dynamic range allows for more contrast between different elements in the audio, while a narrower dynamic range can result in a more consistent loudness overall.
In general, it is recommended to aim for a target loudness of around -14 LUFS for audio that will be streamed or played back on consumer devices, and to leave enough headroom (typically around 3-6 dB) to allow for loudness normalization. It is also important to ensure that the audio does not exceed the maximum peak level for the intended format, and to consider the desired dynamic range for the audio.
For example For 24-bit 48kHz audio in the WAV file format, the higher bit depth will provide more headroom and allow for a greater dynamic range, but you should still be mindful of any specific requirements or guidelines for the intended use of the audio. It is also important to leave enough headroom (typically around 3-6 dB) to allow for loudness normalisation.