IEC-60268-7 Headphone Sequences

IEC-60268-7: Sound System Equipment – Part 7: Headphones and Earphones is an international standard intended to characterize the performance of headphones and earphones. The standard itself is a lengthy document, 9 Sections and 3 Annexes covering 46 printed pages. These SoundCheck sequences focus on the electro-acoustic tests which are detailed in Section 8 “Characteristics to be specified and their method of measurement”.

Five separate sequences are provided, each designed to measure specific characteristics. This approach provides the user with the flexibility to measure all or some of the characteristics of their headphone.

More

Active Noise-Cancelling Headphone Battery Life Test

ANC battery life sequence screenshotThis SoundCheck test sequence measures the performance characteristics of Active Noise Cancelling headphones (ANC headphones) while monitoring the DC voltage and current provided to the headphone by its batteries. The sequence first measures the passive attenuation of the headphone before moving into a loop. The loop plays a 2 minute pink noise stimulus at high output level to accelerate battery drain. During this stimulus period, a current measurement is made by Listen’s DC Connect. Immediately following the stimulus, battery voltage is measured followed by acquisition and analysis of audio parameters (response, THD and THD Normalized). The active attenuation of the headphone is then measured followed by a series of post processing and Autosave steps. The looping continues until no output is detected from the headphone, when the device shuts down due to insufficient battery capacity.

 

 

 

 

More

Headphone Active Noise Cancellation Test Sequence

Screenshot of the final test result for active noise cancellation headphone test, showing active, passive and total attenuation.This SoundCheck test sequence measures headphone active noise cancellation (ANC). It measures both the active and passive noise cancellation and calculates total attenuation over the operating frequency range of the headphones. Passive Attenuation is the amount of noise that is reduced at the ear simply by the headphones being worn. Active Attenuation is the amount of noise that is further reduced by turning on the device’s active cancellation circuits. Lastly, Total Attenuation is the combined reduction in noise from passive and active sources and is what the end user of the product will experience.

To calculate these metrics this SoundCheck test sequence performs three separate measurements using a Head and Torso Simulator and a small speaker which serves as a noise source. This is a simple, low-cost alternative to using a diffuse background noise environment with multiple speakers playing uncorrelated noise, although the sequence could be user-modified to support this.

More