Etymotic invented noise-isolating, in-ear earphones. Etymotic's original insert earphone design, developed for auditory research and medical diagnostics, used balanced armature receivers and established these speakers as the gold standard for high-definition, in-ear earphones. ER•4PT earphones, intended for sound engineers and audiophiles in constant motion, comes equipped with extra accessories and adapters.

Frequency Response 20 Hz - 16 kHz
Accuracy Score 4B (92%) 4S (92%) 4PT (86%)
Transducers balanced armature
Noise Isolation 35-42 dB
Impedance (@1kHz) 4B (100 Ohms) 4S (100 Ohms) 4PT (27 Ohms)
Sensitivity (@1 kHz) SPL at 0.1v 4B (90 dB) 4S (90 dB) 4PT (102 dB)
Maximum Output (SPL) 122 dB
Cable 1.5m
User Replaceable ACCU-Filters Yes
Warranty 2 years