The world's most accurate sound-isolating earphones!

In a Class by Itself

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. The ER-4 MicroPro series earphones were the first earphones commercialized using this technology and are recognized as the world leader in response accuracy, to which all other earphones are compared. After more than 20 years, these reference-quality earphones are still the choice of serious sound engineers, audiophiles and musicians.

ER-4PT, the newest model in the MicroPro series, is intended for sound engineers and audiophiles in constant motion. ER-4PT combines the acoustic characteristics and Features of ER-4P earphones, and comes with extra mobile adapters and accessories for traveling professionals. Also included is an industry-exclusive channel-matching compliance graph, signed by the Etymotic engineer who precision matched and custom tuned the balanced-armature drivers.

ACCU-Driver Technology

• High performance, balanced armature drivers specified for a response accuracy of 86% or better

World leader in sound reproduction

• Unsurpassed frequency response accuracy and sound quality - 86%+ response accuracy from 20 Hz - 16 kHz
• The only earphones with Accu-Driver balanced-armature, precision-matched, custom-tuned drivers
• Highest output sensitivity in its class

Timeless style and fit

• Professional quality and reliability
• An assortment of noise-isolating ACCU-Fit eartip options to ensure proper seal and comfort
• CUSTOM-FIT option available

Highest noise isolation

• First earphones to completely seal the ear
• 98% (35 dB - 42 dB) noise isolation -highest of any earphones or headsets on the market today
• Reduction of outside noise reduces the risk of listening at unsafe levels

Best durability and warranty

• 2-year replacement warranty
• Braid-reinforced cable for extremely low microphonic effect
• ACCU-Filter user-replaceable filters protect the balanced-amature drivers from ear wax

Specifications

For measurements and details of this headphone's performance, please feel free to download this informative data sheet, generously supplied by our friends at innerfidelity.com.  This download provides a series of graphs detailing the headphone's unique frequency response, isolation ability, impedance and phase characteristics, Total Harmonic Distortion characteristics as well as other headphone-specific measurements.