Headphone frequency response varies across listeners by up to 9 dB.

Evidence

The standard deviations increase below 400 Hz varying from 2.5 to 9 dB at 20 Hz. Above 1 kHz the standard deviations rise as high as 8 dB above 8 kHz. One model has unusually high standard deviations in response from 1 to 3 kHz. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1747

Categorization

• QUESTION: Which headphone models and measurement fixtures were used, and does the 1-3 kHz anomaly trace to a specific design cause?