Pinna geometry alone changes headphone measurements through leakage

Evidence

Fixture 2 (GRAS KB5000) has the closest match to Fixture 1 (GRAS 45 CA MOD)—our reference test fixture—other than 1–2 dB attenuation effects below 200 Hz. Since the ear simulators are otherwise identical this is not surprising. The differences can be attributed to more leakage produced by the KB5000 pinna. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1730

Categorization

• DEFINE: Clarifies how pinna-generated leakage shifts low-frequency headphone response independently of the coupler.