BAASnotes.com – Bay Area Audiophile Society

Does Bandwidth Beyond 20khz Improve Sound Quality?

Some folks over at the SlimDevices Forum (here) are currently debating the impact of this 2000 psycho-acoustic scholarly research from Japan.

The results of the study support some remarkable and far-reaching conclusions:

• Frequency content beyond 20khz enhances human perception of music – test subjects favor it over lower-bandwidth material.
• Brain activity can be measured and used to correlate subjective assessments of the subjects.
• The form of ABX testing most commonly used in listening tests – several seconds of sound separated by less than a second of silence while switching samples – is inappropriate to measure a human’s assessment of musical content. The brain takes longer to form aesthetic judgments.

These tests were conducted in a controlled setting using double-blind protocols, direct measurement of brain activity, and  a statistically relevant sample size. Pretty solid.

These conclusions could have far-ranging implications to audiophiles:

•  A high-bandwidth system is necessary to full enjoyment of music.
  • Ever hear of a super-tweeter?
• Properly done, “high resolution” formats (e.g., SACD, HrX) enhance listening enjoyment.
  • More material please! And affordable high-resolution DAC’s….
• The rapid-fire “test tone” method of audio ABX testing is inappropriate to measuring human satisfaction of reproduced music.
  • Ban their use in audiophile settings and discussions.

Wow. Weighty stuff to consider this weekend.”Hypersonic” indeed.

In a future piece, I’ll discuss some of the factors that both the paper and the often-didactic forum discussion miss….