ANC and PNC headphone performance is standardized as insertion loss measured with pink noise.

Evidence

IEC 60628-24 (2023) describes a method for measuring insertion loss from ANC and PNC using uncorrelated pink noise reproduced through eight loudspeakers to approximate a random incidence sound field at the headphone. The 1/3-octave spectrum of the noise is measured first with the headphones removed and then remeasured on the test fixture in both ANC on and off modes. The insertion loss provided by ANC, PNC and combined can be 489. calculated and plotted as level (dB) vs. frequency, and the overall amount calculated as a single number in dB or phons. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1756

Categorization

• DEFINE: Defines the IEC 60628-24 measurement standard and the insertion-loss metric for ANC/PNC headphones.
• QUESTION: Worth chasing the actual 60628-24 standard’s exact pass/fail criteria and how insertion loss in phons is computed.