Maico MA 25 User manual

Operation Manual
MA 25/MA 25e
MA 27/MA 27e

Operation Manual MA 25/MA 25e
MA 27/MA 27e
8104818 Rev. 5
1
29/06/2021
Table of Contents
1 Introduction............................................................................................................ 3
1.1 Intended Use Statement ............................................................................................. 3
1.2 Indications for Use Statement..................................................................................... 3
1.3 Contraindications of Use............................................................................................. 3
1.4 Features and Benefits of the MA 25/MA 25e and MA 27/MA 27e................................ 3
1.5 Description.................................................................................................................. 4
2 For Your Safety...................................................................................................... 5
2.1 How to Read this Operation Manual ........................................................................... 5
2.2 Customer Responsibility ............................................................................................. 6
2.3 Manufacturer’s Liability ............................................................................................... 6
2.4 Regulatory Symbols.................................................................................................... 7
2.5 General Precautions................................................................................................... 8
2.6 Electrical Safety and Measuring Security.................................................................... 8
2.7 Device Control...........................................................................................................10
2.8 Electromagnetic Compatibility (EMC).........................................................................10
3 Warranty, Maintenance and After-Sales Service .............................................. 11
3.1 Warranty....................................................................................................................11
3.2 Maintenance..............................................................................................................11
3.3 Cleaning and Disinfection Recommendations............................................................11
3.4 Disposables...............................................................................................................12
3.5 Accessories/Replacement Parts ................................................................................12
3.6 Recycling and Disposal..............................................................................................12
4 Unpacking and Hardware Orientation................................................................ 13
4.1 Unpacking the System...............................................................................................13
4.2 Hardware Orientation.................................................................................................14
5 Operating the Device........................................................................................... 18
5.1 Getting started with the MA 25/MA 25e and the MA 27/MA 27e.................................18
5.2 Switching the Device On and Off ...............................................................................19
5.3 Device Layout............................................................................................................19
5.4 Function Keys............................................................................................................20
5.5 MA 25e/MA 27e Special Functions............................................................................20
5.6 Screens .....................................................................................................................21
5.7 Preparing for Testing .................................................................................................22
5.8 Tone Setup Menu......................................................................................................23
5.9 Managing Test Results ..............................................................................................27
6 Technical Data ..................................................................................................... 28
6.1 MA 25/MA 25e/MA 27/MA 27e Hardware ..................................................................28
6.2 Connections...............................................................................................................30
6.3 Pin Assignment..........................................................................................................31
6.4 Calibration Values and Maximum Levels ...................................................................31
6.5 Electromagnetic Compatibility (EMC).........................................................................33
6.6 Electrical Safety, EMC and Associated Standards.....................................................37
6.7 Checklist for Subjective Audiometer Testing..............................................................38

Operation Manual MA 25/MA 25e
MA 27/MA 27e
8104818 Rev. 5
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29/06/2021
Title: Operation Manual MA 25/MA 25e –MA 27/MA 27e
Date of issue/last revision: 26/10/2021
All available operation manuals can be found in
the download center on the MAICO homepage:
MAICO Diagnostics GmbH
Sickingenstr. 70-71
10553 Berlin
Germany
Tel.: + 49.30.70 71 46-50
Fax: + 49.30.70 71 46-99
E-mail: [email protected]
Internet: www.maico.biz
Germany:
International:
Copyright © 2021 MAICO Diagnostics
All rights reserved. No part of this publication may be reproduced or transmitted in any
form or by any means without the prior written permission of MAICO Diagnostics. The
information in this publication is proprietary to MAICO Diagnostics.
Compliance
MAICO Diagnostics GmbH is an ISO 13485 certified corporation.
Caution for USA: Federal Law restricts this device to sale by or on the order of a
licensed medical professional

Operation Manual MA 25/MA 25e
MA 27/MA 27e
8104818 Rev. 5
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29/06/2021
1 Introduction
This section offers you important information about:
▪the intended use of the device
▪indications and contraindications of use
▪features and benefits
▪a description of the device
1.1 Intended Use Statement
Screening audiometers are designed for determine hearing thresholds levels. The
instrument is intended for all patient populations over 3 years age and able to respond
to test signal in a rational way.
1.2 Indications for Use Statement
The MA 25/MA 25e/MA 27/MA 27e is a portable or standalone audiometer intended to
be used for the identification of hearing loss and the factors that contribute to the
occurrence of the hearing loss in the age range of children to adults. It is used as part of
a total testbattery to determine hearing acuityby audiologists, ENTs, hearing healthcare
professionals, or othertrained technicians in a hospital, clinic, healthcare facility or other
suitable quiet environment as defined in ISO 8253-1 or ANSI S3.1 or equivalent.
1.3 Contraindications of Use
The patient is too young, sick or uncooperative to perform the tasks.
1.4 Features and Benefits of the MA 25/MA 25e and MA 27/MA 27e
1.4.1 General Information About the MA 25/MA 25e and MA 27/MA 27e
The MA 25/MA 25e and the MA 27/MA 27e gives you the benefit of:
•Portable audiometer
•Multiple transducer options
•Air Conduction
•Pure, Pulse and Warble Tone
•Built-in handle and storage compartment –MA 27 and MA 27e version

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MA 27/MA 27e
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1.4.2 Extended Functions of the MA 25e and MA 27e
The MA 25e and the MA 27e extends the functionalities with the following extra features:
•Communication with a computer, to save and print results with the use of
MAICO Software.
•Automatic Hughson-Westlake patient controlled automatic threshold test
complying with ISO 8253. When the test is completed the results are easily
recalled from the internal memory of the device.
•Talk Forward function allows easy communication with the patient while
wearing the headphone and/or in sound booth installations.
1.5 Description
The MA 25/MA 25e and MA 27/MA 27e audiometers are designed to be a device for
screening for hearing loss. Output and specificity of this type of device are based on the
test characteristics defined by the user, and may vary depending on environmental and
operatingconditions.Thescreeningforhearinglossusingthiskindofaudiometerdepends
on the interaction with the patient. As with any type of hearing screening, a “pass” result
should not overrule any additional concerns regarding hearing ability. A full audiologic
evaluation should be administered if concerns about hearing sensitivity persist.

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MA 27/MA 27e
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2 For Your Safety
This section offers you important information about:
▪how to read the operation manual
▪where to spend special attention
▪the customer responsibility
▪the explanation of all regulatory symbols used
▪important cautions and warnings that have to be considered during the
whole time handling and operating your device
2.1 How to Read this Operation Manual
This Operation Manual contains information pertinent to the use of the MAICO device
system including safety information as well as maintenance and cleaning
recommendations.
READ THIS ENTIRE MANUAL BEFORE ATTEMPTING TO USE THIS
SYSTEM!
Use this device only as described in this manual.
All images and screenshots are only examples and may differ in
appearance from the actual device settings.
In this manual, the following two labels identify potentially dangerous or destructive
conditions and procedures:
The WARNING label identifies conditions or practices that may
present danger to the patient and/or user.
The CAUTION label identifies conditions or practices that could
result in damage to the equipment
NOTE: Notes help you identify areas of possible confusion and avoid potential problems
during system operation.
WARNING
CAUTION

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MA 27/MA 27e
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2.2 Customer Responsibility
All safety precautions given in this operation manual must be observed at all times.
Failure to observe these precautions could result in damage to the equipment and
injury to the operator or subject.
The employer should instruct each employee in the recognition and avoidance of
unsafe conditions and the regulations applicable to his or her work environment to
control or eliminate any hazards or other exposure to illness or injury.
It is understood that safety rules within individual organizations vary. If a conflict exists
between the material contained in this manual and the rules of the organization using
this device, the more stringent rules should take precedence.
This product and its components will perform reliably only
when operated and maintained in accordance with the
instructions contained in this manual, accompanying labels,
and/or inserts. A defective product shouldnot be used. Make
sure all connections to external accessories are snug and
secured properly. Parts which may be broken or missing or
are visibly worn, distorted, or contaminated should be
replaced immediately with clean, genuine replacement parts
manufactured by or available from MAICO.
NOTE: Customer responsibility includes proper maintenance and cleaning of the
device (see sections 3.2 and 3.3). Breach of the customer responsibility can lead to
limitations of Manufacturer’s Liability and Warranty (see sections 2.3 and 3.1).
NOTE: In the unlikely case of a serious incident, inform MAICO as well as the competent
authority in the country where the user is established.
2.3 Manufacturer’s Liability
Usage of the device in a way deviant from the intended use will lead to a limitation or
termination of the manufacturer’s liability in case of damage. Improper use includes
disregarding the operation manual, the operation of the device by underqualified
personnel as well as making unauthorized alterations on the device.
WARNING

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MA 27/MA 27e
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2.4 Regulatory Symbols
The following Table 1 gives an explanation of the symbols used on the device itself,
on the packaging and the accompanying documents including the Operation Manual.
Table 1 Regulatory Symbols
REGULATORY SYMBOLS
SYMBOL
DESCRIPTION
Serial number
Date of manufacture
Manufacturer
Caution, consult accompanying documents
Warning, consult accompanying documents
Return to authorized representative, special disposal
required
Reference number
Medical Device
Patient applied part type B according to IEC 60601-1
Refer to instruction manual (mandatory)
Keep away from rain
Transport and storage temperature range
Transport and storage humidity limitations
Voltage transformer
Do not reuse
Conforms to Medical Device Regulation (EU) 2017/745
ETL listed mark
Logo

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MA 27/MA 27e
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2.5 General Precautions
Before starting a measurement make sure, that the device
works properly.
Use and store the device indoors only. For operation, storage
and transport conditions see table in section Technical Data.
No modification of this equipment is allowed.
Equipment is not user repairable. Repairs must be performed
by a qualified service representative only. No modifications
of the equipment are allowed by anyone other than a qualified
MAICO representative. Modification of the equipment could
be hazardous. No part of the equipment can be serviced or
maintained while in use with the patient.
Do not drop or otherwise cause undue impact to this device.
If the device is dropped or otherwise damaged, return it tothe
manufacturer for repair and/or calibration. Do not use the
device if any damage is suspected.
Calibration of the device: The audiometer and the
transducers complement each other and share the same
serial number (i.e. MA1234567). Therefore, the device shall
not be used with any other transducer prior to recalibration.
Recalibration also needs to be conducted, when a defected
headphone is replaced.
Uncalibrated devices may lead to faulty measurements and
sometimes even damage the hearing of the examinee.
2.6 Electrical Safety and Measuring Security
This icon indicates that patient applied parts of the device
conform to IEC 60601-1 Type B requirements.
In Case of Emergency
In case of emergency, disconnect the device from the
computer.
In Case of Emergency
Incaseofemergency,disconnectthedevice from powersupply.
Position the device in such a way that it can be easily
disconnected from the power supply at any time.
Do not use the device if the power supply unit and/or the
plug is damaged.
WARNING
WARNING
WARNING
WARNING
WARNING

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MA 27/MA 27e
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To transferdatato a PC,establishinga PC-connection viaUSB
is required. See section 4.2.4 on how to safely establish a
connection with a power supplied PC or laptop (medical
device/non-medicaldevice) or to a battery-driven laptop.
This equipment is intended to be connected to other equipment
thus forming a Medical Electrical System. External equipment
intended for connection to signal input, signal output or other
connectors shall comply with the relevant product standard e.g.
IEC 60950-1 for IT equipment and the IEC 60601-series for
medical electrical equipment. In addition, all such combinations
–Medical Electrical Systems –shall comply with the safety
requirements stated the general standard IEC 60601-1, edition
3, clause 16. Any equipment not complying with the leakage
current requirements in IEC 60601-1 shall be kept outside the
patient environment i.e. at least 1.5 m from the patient support
or shall be supplied via a separation transformer to reduce the
leakagecurrents.Anypersonwhoconnectsexternalequipment
to signal input, signal output or other connectors has formed a
Medical Electrical System and is therefore responsible for the
system to comply with the requirements. If in doubt, contact
qualified medical technician oryour local representative.
A Separation Device (isolation device) is needed to isolate
the equipment located outside the patient environment from
the equipment located inside the patient environment. In
particular such a Separation Device is required when a
network connection is made. The requirement for the
Separation Device is defined in IEC 60601-1 clause 16.
If the device is connected to a PC (IT equipment forming a
system) assembly and modifications shall be evaluated by
qualified medical technician according to safety regulations
in IEC 60601-series.
Donot touchthe contacts of the device andthepatientat the same
time.
If the device is connected to a PC (IT equipment forming a
system) do not touch the patient and the IT equipment at the
same time.
The consequence of not following this warning could be a
too high leakage current to the patient.
The device is not intended for operation in areas with an
explosion hazard. Do NOT use the device in a highly
oxygen-enriched environment, such as a hyperbaric
chamber, oxygen tent, etc. If the device is not used switch it
off and disconnect it from the power supply.
Never short-circuit the terminals.
WARNING
WARNING
WARNING
WARNING
WARNING

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MA 27/MA 27e
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To avoid the risk of electric shock, this equipment must only
be connected to the medical power supply originally
delivered by MAICO. Using another power supply can also
lead to electrical damage on the device.
Prevent cable breakage: cables must not be bent or
buckled.
2.7 Device Control
The user of the device should perform a subjective device check once a week
according ISO 8253-1. See section 6.7 for a checklist.
For annual calibration please see sections 2.5 and 3.1
2.8 Electromagnetic Compatibility (EMC)
This device is suitable in hospital environments except for
near active HF surgical equipment and RF shielded rooms of
systems for magnetic resonance imaging, where the intensity
of electromagnetic disturbance is high.
The device fulfills the relevant EMC requirements. Avoid
unnecessary exposure to electromagnetic fields, e.g. from mobile
phones etc. If the device is used adjacent to other equipment it
must be observed that no mutual disturbanceappears.
Use of this device adjacent to orstacked with other equipment
should be avoided because it could result in improper
operation. If such use is necessary, this instrument and the
other equipment should be observed to verify that they are
operating normally.
Use of accessories, transducers and cables other than those
specified or provided by the manufacturer of this equipment
could result in increased electromagnetic emissions or
decreased electromagnetic immunity of this equipment and
result in improper operation.
The list of accessories, transducers and cables can be found
in the section 6.5 of this operation manual.
Portable RF communications equipment (including peripherals
such as antenna cables and external antennas) should be used
no closer than 30 cm (12 inches) to any part of the MA 25/MA
25e/MA 27/MA 27e, including cables specified by the
manufacturer. Otherwise, degradation of the performance of this
equipment could result in improperoperation.
WARNING
WARNING
WARNING
WARNING
WARNING

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MA 27/MA 27e
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3 Warranty, Maintenance and After-Sales Service
This section offers you important information about:
▪warranty conditions
▪maintenance
▪cleaning and disinfection recommendations
▪accessory and replacement parts
recycling and disposal of the device
3.1 Warranty
The MAICO device is guaranteed for at least one year. Ask your authorized local
distributor for more information.
This warranty is extended to the original purchaser of the device by MAICO through
the distributor from whom it was purchased and covers defects in material and
workmanship for a period of at least one year from date of delivery of the device to the
original purchaser.
The device shall only be repaired and serviced by your distributor or by an authorized
service center. Opening the device case will void the warranty.
In the event of repair during the guarantee period, please enclose evidence of
purchase with the device.
3.2 Maintenance
In order to ensure that the device works properly, it has to be checked and calibrated
at least once every 12 months.
The service and calibration must be performed by your dealer or by a service center
authorized by MAICO.
When returning the device for repairs or calibration it is essential to send the acoustic
transducers with the device. Please include a detailed description of faults. In order to
prevent damage in transit, please use the original packing when returning the device.
3.3 Cleaning and Disinfection Recommendations
It is recommended that parts (device and accessories like headphones, ear cushions)
which come in direct contact with the patient be subjected to standard cleaning and
disinfecting procedure between patients.
Recommendations for cleaning and disinfection of MAICO device presented in this
document are not intended to replace or contradict policies in effect or procedures
required for infection control at the facility.
If there is not a high infection potential, MAICO recommends:
•Beforecleaningalwaysswitchoff anddisconnectthe devicefrom the powersupply.
•For cleaning use a lightly dampened cloth with soap water solution.

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MA 27/MA 27e
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•Disinfect the plastic housing of the MA 25/MA 25e/MA 27/MA 27e and its
accessories by wiping the surfaces with disinfectant wipes or a comparable
product. Follow the instructions on the specific disinfection product.
oWipe before and after each patient
oAfter contamination
oAfter infectious diseases
To avoid damage of the device and its accessories, please
mind the following:
•Do not autoclave or sterilize.
•Do not use the device in the presence of fluid that
can come into contact with any of the electronic
components or wiring.
Should the user suspect fluids have contacted the system
components or accessories, the unit should not be used
until deemed safe by a MAICO certified service technician.
Do not use hard or pointed objects on the device or its
accessories.
3.4 Disposables
Use only the Sanibel Supply disposable supplies that are supplied with your device.
Ear cushion covers are intended for single-use only. These
should be discarded after use. They cannot be cleaned.
In case of re-use of the single-use disposables, you enhance the
risk of cross-contamination!
3.5 Accessories/Replacement Parts
Some reusable components are subject to wear with use over time. MAICO
recommends that you keep these replacement parts available (as appropriate for your
MA 25/MA 25e/MA 27/MA 27e device configuration). Ask your authorized local
distributor when accessories need to be replaced.
3.6 Recycling and Disposal
WithintheEuropeanUnionitisillegaltodisposeofelectricandelectronic
waste as unsorted municipal waste. According to this, all MAICO
products sold after August 13, 2005, are marked with a crossed-out
wheeled bin. Within the limits of Article (9) of DIRECTIVE 2002/96/EC
on waste electrical and electronic equipment (WEEE), MAICO has
changed their sales policy. To avoid additional distribution costs we
assign the responsibility for the proper collection and treatment
according to legal regulations to our customers.
Non-European
countries
Outside the European Union, local regulations should be followed
when disposing of the product after its useful life.
CAUTION
WARNING

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MA 27/MA 27e
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4 Unpacking and Hardware Orientation
This section provides information on:
▪unpacking the system
▪components
▪becoming familiar with the hardware inclusive connections
▪how to store the device
4.1 Unpacking the System
Check Box and Contents for Damage
•It is recommended that you unpack your MA 25/MA 25e/MA 27/MA 27e carefully
making sure that all components are removed from the packing materials.
•Verify that all components are included as shown on the packing slip included
with your shipment.
•If any component is missing, contact your distributor immediately to report the
shortage.
•If any component appears to be damaged in shipment, contact your distributor
immediately to report it. Do not attempt to use any component or device that
appears to be damaged.
Reporting Imperfections
Notify the carrier immediately if any mechanical damage is noted. This will ensure that
a proper claim is made. Save all packaging material so the claim adjuster can inspect
it as well.
Report Immediately any Faults
Any missing part or malfunction should be reported immediately to the supplier of the
device together with the invoice, serial number, and a detailed report of the problem.
Keep Packaging for Future Shipment
Save all the original packing material and the shipping container so the device can be
properly packed if it needs to be returned for service or calibration (see section 3.2).
Components
The MA 25/MA 25e/MA 27/MA 27e comes with different components (see Table 2).
The availability of configurations with the following components is country specific.
Contact your local distributor for more information. See also Table 3 for replacement
parts and disposables.

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MA 27/MA 27e
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Table 2 Available Components
Available Components
Base Unit
AC Headphones DD45*
AC Headphones DD45 with RE-7 Headband*
DD65 v2 Headphones*
Power Supply Unit UES18LCPU-050200SPA
MAICO Sessions Kit (USB)
Operation Manual
Quick Guide
Patient Response Switch*
Only for MA 25/MA 25e:
Carrying Bag
3 AA Batteries
*Applied part according to IEC/EN 60601-1
Table 3 Replacement Parts and Disposables
Replacement Parts and Disposables
Ear Cushion Cover
Audiogram Pad
4.2 Hardware Orientation
4.2.1 MA 25/MA 25e and MA 27/MA 27e Devices
MA 25/MA 25e
Figure 1 shows the MA 25/MA 25e device.
Figure 1

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MA 27/MA 27e
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MA 27/MA 27e
Figure 2 shows the MA 27/MA 27e device. The device has a main device layout, a
case to store headsets and cables and a handle to easily carry the device (Figure 3).
The connections are located in the case (Figure 4).
Figure 2
Figure 3
Figure 4
NOTE: See section 5.3 detailed information about the device layout.
Adjusting feet height (MA 27/MA 27e Only)
Figure 5
To adjust the height, turn the device over. Adjust the two feet
by turning them in a counter clockwise to increase height, or
in a clockwise direction to decrease height (Figure 5.)
4.2.2 Connections for Headphones, USB Devices and Power Supply
Figure 6 and Figure 7 show the connections on the rear panel (MA 25/MA 25e) and
the inside panel (MA 27/MA 27e) of the device. The connections are explained in
Table 4. Insert the plugs before turning on the device.
Insert plugs with care into the appropriate connection. Do not
wiggle the plug or pull with force while connected. Disconnect
plugs cautiously.
CAUTION

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MA 27/MA 27e
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Connections
Figure 6
Figure 7
Table 4 Explanation of the Connections
CONNECTIONS
1
Socket for left headphone jack (blue)
2
Socket for right headphone jack (red)
3
Socket for patient response switch
4
Socket for external power supply unit UES18LCPU-050200SPA
4.2.3 Only for MA 25/MA 25e: Battery Compartment
For battery driven use of the MA 25/MA 25e 3x AA batteries have to be placed in the
battery compartment on the backside of the device (Figure 8 and Figure 9).
Figure 8
Figure 9
4.2.4 Establishing a PC-Connection (MA 25e/MA 27e Only)
To transfer data to a PC, establishing a PC-connection via USB is required. If the
MA25e/MA 27e is used with office equipment that is not a medical device itself (see
Table 4, PC-Connection 1), make sure to establish the PC-connection in one of the
following ways (see Table 5, PC Connection 2, 3 or 4).
Make sure you use only office equipment with the device that
is a medical device itself or meets the requirements of
IEC 60950. If a non-medical device is used within the patient
environment (1.5 m from patient as defined in IEC 60601) a
voltage transformer must be used (exception: a battery driven
laptop is used).
WARNING
MA 27/MA27e
MA 25/MA25e
1
1
2
2
3
3
4
4

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Table 5 PC-Connections
PC CONNECTIONS
PC Connection 1:
Medical device –Medical Device
PC Connection 2:
Medical device –Non-Medical Device
PC Connection 3:
Medical device –Non-Medical Device
PC Connection 4:
Medical device –Laptop (battery-driven)
4.2.5 PC-Interface
Connecting the Audiometer to a PC for transferring the results is described in
section 5.9.2.
4.2.6 Storage
When the MA 25/MA 25e/MA 27/MA 27e is not in use, store it in a location where it will
be safe from damage to the sensitive components such as the acoustic transducers
and cables. Store according to the recommended temperature conditions described in
Section 6.1.

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5 Operating the Device
This section offers you information about:
▪how to get started with the device
▪the device layout
▪the function keys and screens
▪preparing the patient for testing
▪performing Tone Audiometric testing
▪changing settings in the tone setup menu
▪managing the test results
5.1 Getting started with the MA 25/MA 25e and the MA 27/MA 27e
5.1.1 Use of Equipment After Transport and Storage
Make sure the device is functioning correctly before use. If the device has been stored
in a colder environment (even for shorter time) allow the device to become
acclimatized. This can take a long time depending onthe conditions (like environmental
humidity). You can reduce the condensation by storing the device in its original
packaging. If the device is stored under warmer conditions than the use conditions, no
special precaution are required before use. Always ensure proper operation of the
device by following routine check procedures for audiometric equipment.
5.1.2 Where to Setup
The MA 25/MA 25e and MA 27/MA 27e should be operated in a quiet room, so that
the audiometric examinations are not influenced by outside noises. Ambient sound
pressure levels in an audiometric test room shall not exceed the values specified in the
norm ISO 8253-1:2010 or ANSI S3.1-1999..
Devices, which emit strong electromagnetic fields (e.g. cellphones, microwaves or
radiotherapy devices), can influence the function of the audiometer. Therefore, it is not
recommended to use these devices in close proximity to the audiometer as it may lead
to incorrect test results.
The test room must be at a normal temperature, usually from 15° C/59° F to 35 °C/95° F,
and the device should be switched on approximately 10 minutes before the first
measurement. For furtherinformation on use aftertransport and storage see section 6.1.
Place the device ona stable counter ortable. Connectall accessories with the appropriate
sockets as shown in Section 4.2.2. Plug the power cord into a grounded outlet.

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5.2 Switching the Device On and Off
NOTE: All the cables and accessories have to be connected before the instrument is
switched on. Power on is only possible if headphones are completely plugged-in!
NOTE: The warm-up time for the device including boot up process takes about
1 minute. For further information on use after transport and storage see Section 6.1.
To turn on the audiometer press the Tone Switch button (Figure 10/Figure 11, 1).
To power off the audiometer press and hold the Hearing Level dB dial (2) and
Frequency Hz dial (3) for a few seconds or unplug the device.
5.3 Device Layout
Figure 10 and Figure 11 show the device layout. Table 6 gives further explanation.
Figure 10
Figure 11
Table 6 Explanation of Device Layout
#
Name(s) /
Function (s)
Description
1
Tone Switch
Presenter mode: Press to present the signal. A tone
presentation signal (i.e. ) will display on the screen.
Interrupter mode: Press to stop the signal being
presented.
2
Hearing Level dB
Dial to select hearing level of presented tone
between -10 dB HL and 100 dB HL.
3
Frequency Hz
Dial to select frequency of presented tone.
4
Function Keys F1-F4
See section 5.4 for more details.
1
2
3
4
MA 27/MA27e
1
2
3
4
MA 25/MA25e