EN IEC 60118 Electroacoustics - Hearing Aids

The “EN IEC 60118 Electroacoustics - Hearing aids” standard, which is based on a European standard and later published by the International Electrotechnical Commission (IEC), consists of the following subsections published under the same title:

The standard “EN IEC 60118-0 Part 0: Measurement of the performance characteristics of hearing aids” provides recommendations for measuring the performance characteristics of air conduction hearing aids measured with an acoustic coupler or a plugged ear simulator. This standard applies to the measurement and evaluation of the electroacoustic characteristics of hearing aids, for example for type testing and manufacturer data sheets. This standard also applies to the measurement of the performance characteristics of hearing aids for quality assurance purposes in production, supply and delivery.

The measurement results obtained by the methods specified in this standard express the performance under the measurement conditions and may deviate significantly from the performance of the hearing aid under actual conditions of use. This standard uses an acoustic coupler according to the IEC 60318-5 standard, which is primarily designed to load a hearing aid with the specified acoustic impedance only and is not designed to reproduce the sound pressure at a person's ear.

For measurements that reflect the output level of a normal human ear, a plugged ear simulator can be used according to IEC 60318-4. For extended high-frequency measurements and deep-tip hearing aids, an acoustic coupler can be used according to IEC 60318-8. This standard also covers the measurement of hearing aids with non-acoustic inputs such as wireless, inductive or electrical inputs.

This standard does not cover the measurement of hearing aids for simulated on-site operating conditions to which EN IEC 60118-8 is applicable. This standard does not cover the measurement of hearing aids using a speech-like signal and typical user settings to which EN IEC 60118-15 is applicable.

The standard “EN IEC 60118-1 Part 1: Hearing aids with induction pickup coil input” describes a method for determining the electroacoustic performance of hearing aids fitted with an induction pickup coil and used in an audio-frequency magnetic field. The induction pickup performance is measured in a loop simulating usage conditions in room applications. The performance of induction pickup coils in telephone magnetic fields may differ from the results obtained using this standard.
The standard “EN IEC 60118-2 Part 2: Hearing aids with automatic gain control circuits” applies to all types of hearing aids with automatic gain control circuits. This standard provides uniform methods for determining the dynamic and static performance characteristics of hearing aids with automatic gain control circuits and the associated measurement methods for these characteristics. This standard is limited to the description of the different characteristics and the associated measurement methods. It does not attempt to specify performance requirements.

This standard includes devices that have compression or limiting features with respect to the envelope of the input signal. Devices that control the long-term average output level are also included.

Automatic gain control is used to reduce the dynamic range of the output audio in order to achieve compression or maintain the integrity of the input waveform.
For limiting purposes, automatic gain control circuits are often used instead of clipping devices.

A limiting effect occurs when the input/output characteristic flattens at higher input levels. The limiting action is primarily used as a way to prevent excessive output sound from the hearing aid from reaching the listener's car.

This standard does not include:

Extenders.
Clipping devices that cut off signal peaks above a certain level. Such devices differ fundamentally from automatic gain control circuits, which tend to maintain the waveform of the input signal in a steady state.

An automatic gain control circuit with a very short recovery time can cause significant distortion, especially in the low frequency range. Special attention should be paid to this.

The standard “EN IEC 60118-3 Part 3: Hearing aid equipment not wholly attached to the listener” describes a method for determining the overall electro-acoustic performance of hearing aid equipment used in the rehabilitation of hearing impaired people. However, this standard has been withdrawn.
The standard "EN IEC 60118-4 Part 4: Induction loop systems for hearing aid purposes - System performance requirements" is applicable to audio frequency induction loop systems designed to provide an input signal for hearing aids operating with an induction pickup coil (telecoil) and producing an alternating magnetic field at audio frequencies. Throughout this standard it is assumed that the hearing aids used with it comply with all relevant parts of EN IEC 60118.

This standard specifies field strength requirements in audio-frequency induction loops for hearing aid purposes. This provides adequate signal-to-noise ratio without overloading the hearing aid. The standard also specifies minimum frequency response requirements for acceptable intelligibility. Methods for measuring magnetic field strength are specified and information is given on suitable measuring equipment, information to be provided to the operator and users of the system, and other important matters.

This standard does not specify requirements for loop drive amplifiers or associated microphone or audio signal sources as discussed in IEC 62489-1, or for field strengths produced by equipment within the scope of ITU-T P.370, such as telephone handsets.

The standard “EN IEC 60118-5 Part 5: Eartips” applies to eartips that can be attached to an earmold that is inserted into the ear canal. This standard defines the dimensions required to ensure interchangeability of eartips when used with earmolds or other ear-worn devices.
The standard “EN IEC 60118-6 Part 6: Characteristics of electrical input circuits for hearing aids” describes the electrical and safety characteristics of a circuit for an external electrical input to a personal hearing aid, in order to ensure compatibility with external electrical or electroacoustic signal sources. In this standard, the hearing aid may include an adapter (sound socket) containing the connector systems described in the standard EN IEC 60118-12.
The standard "EN IEC 60118-7 Part 7: Measurement of the performance characteristics of hearing aids for production, supply and delivery quality assurance purposes" describes recommendations for measuring the performance characteristics of air conduction hearing aids of a specific model for production, supply and delivery quality assurance purposes. The manufacturer normally assigns nominal values.

This standard should not be used as the basis for exchanging information on hearing aid specifications in general, nor is it intended to be used as a predictor of real-ear performance. Terms such as manufacturer and purchaser in this standard are understood to refer to the supplier and purchaser, respectively, in any hearing aid supply arrangement where the use of this standard is required. Although the number of measurements covered by this standard is limited, it is not intended that all measurements described herein be made in every situation.

The latest update of this standard now specifies performance requirements. Conformity to this standard is achieved only when a measurement result lies exactly within the tolerances specified in this standard expanded by the values given in the table when expanded by the actual expanded measurement uncertainty of the testing laboratory. For custom-made in-the-ear devices, the data provided by the manufacturer applies only to the specific hearing aid under test.

The standard “EN IEC 60118-8 Part 8: Methods for measuring the performance characteristics of hearing aids under simulated in situ operating conditions” describes methods for a test simulating the acoustic effects of an average adult user on the performance of a hearing aid. It specifies specific guidelines for simulated in situ measurements of hearing aids and includes a simplified method for simulated in situ measurements of hearing aids and a description for determining the directivity index of directional microphones in hearing aids in the horizontal plane. In addition, the update of this standard now specifies tolerances. Compliance with the specifications in this standard is demonstrated only when the result of a measurement is fully within the test laboratory’s actual expanded measurement uncertainty, expanded by the values of the tolerances specified in this standard.
The standard EN IEC 60118-9 Part 9: Methods for measuring the performance characteristics of bone conduction hearing aids describes methods for measuring the characteristics of bone conduction hearing aids. These methods provide a suitable basis for the exchange of information or direct comparison of the electroacoustic characteristics of bone conduction hearing aids. These methods have been selected to be practical and reproducible and are based on selected fixed parameters.

The results obtained by the methods specified in this standard express the performance under measurement conditions, but the performance of the hearing aid under practical use conditions depends on a number of factors (e.g. effective load impedance, environmental conditions, acoustic environment).

This standard defines methods for measuring the characteristics of bone conduction hearing aids, both for transcutaneously coupled devices measured on a mechanical coupler meeting the requirements of IEC 60318-6 and for bone-anchored/bone-anchored devices measured on a skull simulator.

The standard “EN IEC 60118-10 Part 10: Guide to hearing aid standards” contains a guide to the appropriate IEC publications on hearing aids. This standard contains a glossary of terms and the scope of each publication. Specific measurement requirements are specified. The method for classifying hearing aids is given by the maximum saturation sound pressure level. However, this standard has been withdrawn.
The standard “EN IEC 60118-11 Part 11: Symbols and other markings on hearing aids and related equipment” applies to symbols and other markings on hearing aids and related equipment for the purpose of identifying control settings and providing information on technical functions and features. This standard provides symbols and markings for the benefit of users and those involved in the fitting of hearing aids and related equipment.
The standard “EN IEC 60118-12 Part 12: Dimensions of electrical connecting systems” applies to plug and connector systems for hearing aids and specifies dimensions and tolerances to ensure interchangeability.
The standard “EN IEC 60118-13 Part 13: Requirements and methods of measurement for electromagnetic immunity of mobile digital wireless devices” covers the relevant electromagnetic (EMC) phenomena for hearing aids. Hearing aid immunity to high-frequency fields from digital wireless devices such as mobile phones has been identified as one of the most relevant EMC phenomena affecting hearing aids.
The standard “EN IEC 60118-14 Part 14: Characteristics of digital interface devices” describes the electrical and mechanical requirements for a digital interface device to allow a general purpose control device, such as a desktop computer, to be connected to hearing aids for the purpose of electrically adjusting their operating parameters. This standard provides a specification such that all hearing aid parameters that can be programmed by the specified digital interface device can be adjusted by a single control device and interface device.
The standard “EN IEC 60118-15 Part 15: Methods for characterizing signal processing in hearing aids with a speech-like signal” describes the procedures and requirements for measuring the international speech test signal, a test signal designed to represent normal speech, and the signal processing characteristics in air conduction hearing aids. The measurements are used to derive the estimated insertion gain. For the purposes of characterizing a hearing aid for manufacture, supply and delivery, the procedures and requirements for deriving the coupler gain on a 60318 cm5 coupler, as defined in the standard IEC 2-3, are also specified.

The intent of this standard is to ensure that the same measurements made on a hearing aid, following the procedures described and using equipment that complies with these requirements, will produce essentially the same results. Measurement methods that take into account the acoustic coupling of a hearing aid to the individual ear and the acoustic effect of an end user's individual anatomical variations on the acoustic performance of the hearing aid are known as real ear measurements and are outside the scope of this specific standard.

The standard “EN IEC 60118-16 Part 16: Definition and verification of hearing aid characteristics” describes definitions for common hearing aid characteristics such as noise reduction or feedback reduction. Only acoustic inputs are considered in this standard. Binaural characteristics are not currently covered in this standard. This standard also describes measurement procedures for verifying hearing aid characteristics. The aim is to verify the existence and function of the characteristics, not to evaluate their performance.

Furthermore, the definitions and procedures are kept as general as possible so that this standard can be applied to various types of hearing aids, for example air conduction hearing aids or bone conduction hearing aids. For this purpose, the general definition for the term hearing aid given in EN IEC 60118-0 is adopted and this standard does not refer to a specific ear simulator or acoustic coupler, but instead uses the general definition of a coupler. However, if a general view is not applicable or would lead to ambiguous or confusing wording, only the case for an air conduction hearing aid is considered. However, a description is given of how this standard can be applied to hearing aids that do not use air conduction.

The standard “EN IEC 60118-17 Part 17: Sound broadcasting systems for hearing aids in the 2,4 GHz band” contains recommendations for measuring the performance characteristics of air-conduction hearing aids of a specific model for quality assurance purposes in production, supply and distribution.

In short, the EN IEC 60118 standard is important because it provides a global framework for the performance, testing and safety of hearing aids and associated systems. This standard ensures that hearing aids meet the essential requirements for functionality, compatibility and user protection.

Our organization, which has been trying to support businesses from every sector with its testing, measurement, analysis and evaluation studies carried out in a wide range for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services in accordance with the "EN IEC 60118 Electroacoustics - Hearing aids" standard are also provided to businesses.