As interesting as the first response to your post is, sampling frequency and number of bits are unrelated. Adding bits doesn't have anything to do with Nyquist and filtering approaches.
Word length is increased by adding noise to the signal (aka, dithering). Interpolatuion (guessing) would only apply if you increased the sampling rate such that you had to 'fill in' the missing samples. In the case of more bits and a higher sampling rate, you would combine both interpolation and dithering.
Word length is increased by adding noise to the signal (aka, dithering). Interpolatuion (guessing) would only apply if you increased the sampling rate such that you had to 'fill in' the missing samples. In the case of more bits and a higher sampling rate, you would combine both interpolation and dithering.