Measurement of insertion loss and gain in variable hear-through and noise cancellation modes of true wireless earbuds

This paper presents the results of objective tests to assess the insertion loss and gain performance of three true wireless earbuds that featured both active noise cancellation (ANC) and hear-through functionality. An acoustic test fixture (ATF) was used to examine the earbuds’ attenuation and boosting of broadband noise, linearity of performance for different presentation levels, and consistency of performance over time. The results show that devices are capable of a wide range of both attenuation and boosting, with hear-through modes providing significant levels of boosting in frequencies that are considered important to the intelligibility of speech. Furthermore, none of the hear-through modes tested were found to provide responses that suggested the devices were capable of providing full acoustic transparency. The results may also be useful for those seeking to produce models that replicate key aspects of insertion loss and gain performance in contemporary true wireless earbuds.