ER-3C-10 Insert Earphones

ER-3C-10ER-3C-10 Insert Earphones System $549.24
ER-3C-10ER-3C-10-FC Factory calibration with Neuro-Audio $412.62
ER-3C-10ER3-EC Accessory Set for Non-invasive Electrocochleography – ECochG $318.78
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Insert Earphones for Audiometry and AEP


Quick Overview


Etymotic Research ER-3C™ Insert Earphones are the next generation of insert earphones, replacing ER-3A earphones, which have been the worldwide standard for audiometric insert earphones since 1985.


The frequency response and performance characteristics of ER-3C earphones are virtually identical to the original ER-3A earphones at all audiometric frequencies.


ER-3C key features:

• Incorporates “touch-proof” electrical connection for safety.

• Duplicates ER-3A smooth frequency response.

• 30+ dB external noise exclusion – equivalent to a single-wall booth when used with deeply-sealed foam eartips.

• 70+ dB isolation (interaural attenuation) between ears; reduces the need for masking.

• Reduces test/retest variability compared to supra-aural earphones.

• Eliminates test errors due to collapsed ear canals.

• Simplifies RECD (Real-Ear-to-Coupler-Difference) measurements.

• May be calibrated in a 2-cc coupler, occluded ear simulator, or 0.4-cc coupler.

General features


Intended use


ER-3 Series earphones are intended for use with audiometric equipment used in hearing testing in Audiology and Otolaryngology clinics, auditory research, and screening in industrial and educational settings.


They are well suited for unfavorable test environments that may have high ambient noise levels. The frequency response and performance characteristics of ER-3C earphones are virtually identical to the original ER3-A earphones at all audiometric frequencies and approximate those of Telephonics® TDH-39, 49, and 50 supra-aural earphones.




· Disposable foam eartips are recommended for most uses. They are available in three diameter sizes:

o Standard 8-13 mm – ER3-14A,

o Small 6-9 mm – ER3-14B,

o Large 10-14 mm – ER3-14C.


· Disposable PVC infant eartips are available in two sizes:

o 3.5 mm – ER3-14D,

o 4 mm – ER3-14E.


· Single-Use Eartips™ in multiple sizes of 3 mm-16 mm, which are commonly used in immittance and otoacoustic emissions (OAE) testing, can be used with ER3-06X Single-Use Earptip adapters.


NOTE: No data are available on the interaural attenuation or noise exclusion of Single-Use Eartips with ER-3C Insert Earphones.


· Tiptrodes – gold-foil-plated eartips for non-invasive Electrocochleography (ECochG) are available in two sizes:

o Standard 13 mm – ER-26A.

o Small 10 mm – ER-26B.


CAUTION: All eartips, regardless of material or construction, are for single person use only. Replace eartips for each test session. Do not reuse eartips.


External noise exclusion


ER-3C Insert Earphones provide greater than 30-dB exclusion of background noise. As insertion depth increases, the amount of attenuation increases. Deeply-inserted ER3 foam eartips can provide noise exclusion equivalent to a single-wall booth.


Testing to audiometric zero can be done reliably whenever the SPL of the background noise is less than 45 dBA.


ER-3C Insert Earphones have significantly greater attenuation than traditional supra-aural earphones and circumaural earphones.


Interaural attenuation and masking


High interaural attenuation ER-3C Insert Earphone values reduce the need for masking air-conduction thresholds when using Insert Earphones.


In cases of severe bilateral conductive hearing loss, a masking dilemma (overmasking) occurs when a high level of masking in the non-test ear reaches the opposite (test ear) cochlea via bone conduction and elevates threshold in the test ear.


Interaural attenuation is significantly higher with insert earphones, making it possible to use lower masking levels in the non-test ear.


ER-3 Earphones interaural attenuation increases with eartip insertion depth.


Test reliability


Insert earphones eliminate all three major problems associated with traditional supra-aural earphones:


1. Good noise exclusion at low frequencies, as opposed to poor noise exclusion in supra-aural earphones that invalidates tests done outside a sound booth.


2. High interaural attenuation, as opposed to low interaural attenuation in in supra-aural earphones.


3. Correct high-frequency thresholds in patients with collapsed ear canals, as opposed to erroneous high-frequency thresholds resulting from collapsed ear canals when using traditional MX-41AR earphone cushions.


Wilber et al. (1988) also found less variability, on average, across subjects using insert earphones as compared to traditional supra-aural earphones.


Low electromagnetic emissions (EMI)


Insert earphones emit lower electromagnetic emissions (EMI) causing lower EMI artifacts

in Auditory Evoked Potential (AEP) recording, especially short-latency AEPs like Cochlear Microphonic (CM) and Auditory Brainstem Response (ABR), also known as Brainstem Auditory Brainstem Potential (BAEP).


This feature makes Insert Earphones transducers of choice in AEP recording and standard in most AEP equipment worldwide.


Frequently asked questions about ER-3C Insert Earphones


1. Do I have to calibrate insert earphones, or can I just plug them in and use them?


Earphones always have to be calibrated prior to use. Unless the audiometer was purchased with ER-3 Series earphones pre-calibrated by the equipment manufacturer, the Reference Equivalent Threshold Sound Pressure Levels (RETSPL) values and procedure cited in the current version of the ANSI S3.6 or IEC 60645-1 Standard must be used to calibrate the equipment prior to initial use.


Before calibration, confirm that the impedance of the earphones matches the requirements of the audiometric equipment. The labels on the earphones identify the impedance.


Re-calibration should subsequently be performed at intervals specified by the equipment manufacturer, in compliance with applicable national and international standards and regulations.


Correction factors can be applied where it is necessary to alternate between insert earphones and a supra-aural earphone with audiometers that do not provide a dual-calibration option.


Re-calibration is not required with cable replacement.


2. Can I disinfect and reuse the foam eartips?


No. Hard, non-porous objects and surfaces are the best candidates for disinfection. Unfortunately, insert eartips are neither. They are porous and soft and do not disinfect well.


More importantly, if they are soaked in a solution, the solution is almost certain to stay within the tips thus posing a health hazard to the person who uses it. This is particularly true if someone soaks such a tip in glutaraldehyde (Cidex, Wavicide). The residual glutaldehyde is toxic to the person who receives this tip in the ear.


3. Can I use the foam eartips on several patients before discarding them?


No. Insert eartips were designed to be a single-use item, thrown away after each use. Items like insert eartips can become contaminated by the ear or the hands, and can present a health hazard to the next patient, particularly those with diminished immune systems.


Audiology patients often have weakened immune systems due to age, underlying disease state (diabetes, HIV), or drug treatment (chemotherapy). Ubiquitous organisms passed from person to person via insert eartips can cause opportunistic infections. Insert eartips should always be thrown away after a single use. Supporting research is as follows:


a) Breathnach, Jenkins and Pedler (1992) found that 26 of 29 stethoscopes were contaminated with staphylococci, and concluded that stethoscopes were a vector for staph infections.


Breathnach, A.S., Jenkins, D.R. & Pedler, S.J. (1992) Stethoscopes as possible vectors of infection by staphylococci. British Medical Journal, 305:1573.


b) Brook (1985) evaluated airline headsets worn by 20 male passengers and found them to be contaminated with staph aureus, staph epidermis, streptococci and corynebacterium. This study led to airlines using disposable headphones and better disinfection of headphones.


Brook, I. (1985) Bacterial flora of airline headset devices. American Journal of Otolaryngology 6:111-114.


c) Bankaitis (2000) examined in-the-ear hearing aids and found that ten of ten were contaminated with bacteria and fungus. While most of the bacteria found on the hearing aids were of the varieties normally found in the ear, some were not normally found in the ear, like fecal-born bacteria. This demonstrated that items that come in contact with the ears can become contaminated by the ear or by the hands.


Bankaitis, A.U. (2000) Hearing aid infection control (IRB #10679) submitted for publication. St. Louis University, St. Louis, MO.


Care for ER-3 Series earphones


· Use a damp cloth to wipe down any parts that become soiled during normal use.


· An antimicrobial such as WAVICIDE-01® is safe for external surfaces. Any other agents must be tested before using to prevent damage.


· Do not submerge earphones in liquid or allow liquid into the sound delivery tubes.


· Do not use alcohol or other strong chemicals or solvents to clean earphones or any parts, including cables, sound delivery tubes and eartips.

Performance characteristics – ER-3C-10 (10 Ohms)


10 Ohm

Cable length

7’ (2.13 m)


dual-mono 1/4” (6.33 mm)

Sensitivity (10 Ohms) in HA-2 coupler at 0.1 Vrms

102.5 dB SPL

Maximum output at standard audiometric frequencies between 500 Hz and 4000 Hz

≥ 110 dB HL

Safe operating limits – maximum continuous sine wave drive (10 Ohms)

2.5 Vrms

General characteristics


from +15 to +35°C

Relative humidity

30 90 % (non-condensing)

Ambient pressure

98 104 kPa

ER-3C-10 System


ER-3C-10 Insert Earphones (10 Ohm) – pair, Red and Blue

1 pair

ER-84 7' cable with dual-mono 6.33 mm (1/4") plugs

1 pc.

ER3-14A Foam eartips (regular, 13 mm) – for AEP and PTA

20 pcs.

ER3-14B Foam eartips (baby, 10 mm) – for AEP and PTA

20 pcs.

ER3-14C Foam eartips (jumbo, 18 mm) – for AEP and PTA

2 pcs.

ER3-21 Sound delivery tubes with adapters – Red and Blue

1 pair

ER3-05 Hook-and-loop neck strap with clips

1 pc.


ER3-EC Accessory Set for Non-invasive Electrocochleography – ECochG


ER3-28S Electrode eartip cable for Tiptrodes – pair, Red and Blue

1 pair

ER-26A Gold-plated eartip-electrode (Tiptrode) – regular, 13 mm

20 pcs.

ER-26B Gold-plated eartip-electrode (Tiptrode) – baby, 10 mm

20 pcs.


ER-3C-10-FC Factory calibration with Neuro-Audio AEP System


ER-3C-10-FC Factory calibration with Neuro-Audio Electronic Unit



Customized accessory sets


Accessory set, such as reatip types and quantities, can be customized to specific needs of a clinic or research lab.


Contact us to discuss your accessory needs.

Etymotic Research, Inc. warrants each insert earphone it manufactures to be free of defects in material and workmanship for a period of one year from the date of sale to the original purchaser.

Etymotic Research’s obligation under this warranty is fulfilled, at ERI’s option, by replacing the product in kind without charge to the original purchaser, repairing the part, or crediting the original purchaser with the purchase price of the returned defective part.

For a part to be covered by the warranty it must be returned to Etymotic Research, postage prepaid, within the warranty period, and the part must not show evidence of misuse, neglect, incorrect wiring by others, or improper installation.

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