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Nyquist is rightly sited for 44.1 being established (plus room for
filtering) as a suitable sampling rate for reproducing all frequencies
within the audible spectrum.
As was previously mentioned, anti-aliasing filters in audio converters @
44.1 have been shown to introduce rippling into the higher end of the audio
spectrum, thus using 48k pushes the ripple out of the audio spectrum.
Here is an excerpt from Ken Pohlmann's *Measurement and Evaluation of
Analog-to-Digital Converters* *Used in the Long-Term Preservation of Audio
Recordings*
"It can be argued that high sampling frequencies improve
the binaural time response, leading to improved imaging in multichannel
recordings. For
example, if short pulses are applied to each ear, a 15-ìS difference
between the pulses
can be heard, and that time difference is shorter than the time between two
samples at 48
kHz. Some people can hear a 5-ìS difference, which corresponds to the time
difference
between two samples at 192 kHz. In theory, a high sampling frequency might
improve
spatial imaging.
Similarly, higher sampling frequencies provide improved temporal response.
For
example, the sampling interval at 44.1 kHz is 22.7 ìS; at 192 kHz, it is
5.2 ìS. Musical
instruments can generate transients with rise times of less than 10 ìS. As
another
example, room reverberation comprises a large number of reflections
arriving at high
rates. For example, reverberation might comprise 500,000 arrivals per
second; spaced
regularly, this time interval is less than 2 ìS. Human subjects are
sensitive to interaural
time delays of between 2 and 10 ìS. Subjects have differentiated between a
regular pulse
train and one with deviations of 0.2 ìS. Higher sampling frequencies
clearly preserve
temporal response (Woszczyk 2003)."
You might argue that even an oral history, if there was a nice roomy sound
or outdoor ambience, could benefit from preserving the intangible quality
of the space that the history was given in at 96kHz or more. OR, would a
linguist benefit from analyzing oral histories preserved at higher sampling
rates even though it wasn't the intended use of the recording originally?
Best,
Alex Kroh
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