AmpliVox 270+ User manual

270+
Operating Manual

i
D-0126050 rev 1 - 270+ Operating Manual
ABOUT THIS MANUAL
READ THIS OPERATING MANUAL BEFORE ATTEMPTING TO USE THE INSTRUMENT.
This manual is valid for the 270+ (from firmware version 1.3.1.0 onwards).
This product is manufactured by:
Amplivox Ltd
3800 Parkside, Solihull Parkway,
Birmingham Business Park, Birmingham,
West Midlands,
B37 7YG
www.amplivox.com
For all enquiries please contact us under:
Amplivox Ltd
10393 West 70th Street
Eden Prairie
MN 55344
Tel: [phone]
Fax: [phone]
[e-mail]
Amplivox Ltd
3800 Parkside, Solihull Parkway,
Birmingham Business Park, Birmingham,
West Midlands,
B37 7YG
Tel: [phone]
[email protected]om

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D-0126050 rev 1 - 270+ Operating Manual
TABLE OF CONTENTS
1. INTRODUCTION 5
1.1. THANK YOU 5
1.2. INTENDED APPLICATIONS 5
1.3. CONTRAINDICATIONS 5
1.4. STANDARD AND OPTIONAL ACCESSORIES 6
1.5. WARNINGS 6
2. UNPACKING AND INSTALLATION 7
2.1. GENERAL 7
2.2. MARKINGS 7
2.3. SAFETY INSTRUCTIONS 8
2.3.1. General 8
2.3.2. Cautions –General 9
2.3.3. Environmental factors 10
2.3.4. Electrical and electrostatic safety 10
2.3.5. Electromagnetic compatibility (EMC) 10
2.3.6. Explosion hazards 11
2.3.7. Measuring accuracy 11
2.3.8. Miscellaneous 11
2.3.9. Use of equipment after transport and storage 11
2.3.10. Mains Supply Operation 12
2.4. CONNECTIONS 12
2.5. CONTROLS AND INDICATORS (BASE UNIT) 13
2.6. LIGHT INDICATORS 14
2.7. HARDWARE INSTALLATION 14
2.8. THE SANIBEL MPT-II PRINTER 15
2.8.1. Installing the sanibel MPT-II Printer 15
2.8.2. Switching the Printer on and off 15
2.8.3. Using the Printer 15
3. PRINCIPLES OF OPERATION 16
3.1. OTOSCOPIC EXAMINATION 16
3.2. PRINCIPALS OF PURE TONE AUDIOMETRY 16
3.3. PRINCIPALS OF SPEECH AUDIOMETRY 16
3.4. PRINCIPALS OF FREEFIELD AUDIOMETRY 16
4. USING THE 270+ 17
4.1. GENERAL PRECAUTIONS 17
4.2. SWITCHING THE INSTRUMENT ON AND OFF 17
4.3. SWITCHING HEADPHONES 17
4.4. OPERATING LANGUAGE 18
4.5. SYSTEM INFORMATION 18
4.6. FUNCTION BUTTONS 19
4.6.1. Presenting a tone 19
4.6.2. storing a Test point 19
4.6.3. Talkover and Talkback 19
4.6.4. Menu Operation 20
4.6.5. Clear (on-screen results) 20

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D-0126050 rev 1 - 270+ Operating Manual
4.6.6. Signal 21
4.6.6.1. Selection of Tone and speech module 21
4.6.6.2. Continuous, present and Pulse 21
4.6.7. Ear (Selection) 21
4.6.8. mask (activate masking) 22
4.6.9. output (Ac, BC and freefield) 22
4.6.10. AUTO (automATIC testing) 22
4.6.11. >100dB (extended range) 22
4.6.12. special (Special test selection) 23
4.7. MENU 24
4.7.1. General 24
4.7.2. Configuration 24
4.7.2.1. Auto-TEst Settings 25
4.7.3. Load/Save 25
4.7.4. Print 26
4.8. PERFORMING PURE TONE AUDIOMETRY 27
4.8.1. pure tone Screen 27
4.8.2. Clearing previous Results 27
4.8.3. Performing pure Tone audiometry 28
4.8.4. Masking (Pure tone audiometry) 28
4.8.4.1. BC Masking Transducers 28
4.8.4.2. Masking Intelligence 29
4.8.4.3. Manual Masking 29
4.8.5. Automatic testing (Pure tone audiometry) 30
4.8.6. Automatic testing with masking (Pure tone audiometry) 30
4.8.7. Freefield presenting (Tone Testing) 31
4.9. PERFORMING SPEECH AUDIOMETRY 32
4.9.1. General 32
4.9.2. Test ear 32
4.9.3. Monitor function 32
4.9.4. Using live speech (eMic.) 33
4.9.5. Using Recorded speech (Line) 33
4.9.6. Measuring the SRT Score 33
4.9.7. Masking (Speech Testing) 34
4.9.8. Freefield presenting (Speech Testing) 34
4.10. PERFORMING SPECIAL TESTS 35
4.10.1. Stenger (Tone Audiometry) 35
4.10.2. Performing ABLB 35
4.10.3. Performing SISI 36
4.10.4. Performing MHA 37
4.10.5. Performing HLS 38
4.10.6. Performing Decay 38
4.11. TRANSFERING DATA TO PC 39
5. ROUTINE MAINTENANCE 40
5.1. GENERAL MAINTENANCE PROCEDURES 40
5.2. CLEANING THE 270+ 41
5.3. CLEANING THE ACCESSORIES 41
5.3.1. Transducer Maintenance 41
5.3.2. Earphones 41

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D-0126050 rev 1 - 270+ Operating Manual
5.3.3. Insert Masker 41
5.3.4. Insert Earphones 41
5.3.5. Mains adapter maintenance 42
5.4. ACCESSORIES/REPLACEMENT PARTS 42
5.5. REPAIR 42
5.6. WARRANTY 42
5.7. CALIBRATION AND RETURN OF THE INSTRUMENT 43
6. TECHNICAL SPECIFICATIONS 44
6.1. STANDARD AND REGULATORY 44
6.2. GENERAL 44
6.3. TONE AUDIOMETRY 45
6.4. SPEECH TESTING 46
6.5. MAXIMUM HEARING LEVELS PROVIDED BY EACH FREQUENCY 46
6.6. EARPHONE SOUND ATTENUATION CHARACTERISTICS 46
7. EMC GUIDANCE & MANUFACTURER’S DECLARATION 47
8. APPENDIX A - FREE FIELD CALIBRATION PROCEDURE 52
8.1. GENERAL 52
8.2. ASSURANCE OF CALIBRATION 52
8.3. EXTERNAL LOUDSPEAKER 52
8.4. CALIBRATION SET-UP 52
8.5. FREEFIELD SPEECH CALIBRATION 53
8.5.1. General 53
8.5.2. Calibrating the speech channel: Equalisation (Optional) 53
8.5.3. Level Setting 53
8.5.4. Calibrating the Competing Noise Channel 54
8.6. FREEFIELD WARBLE TONES CALIBRATION 54
8.6.1. Entering Free Field Calibration Mode 54
8.6.2. Calibration Procedure 54
8.6.3. Calibrating the Competing Noise Channel 55
8.7. FREEFIELD LIVE SPEECH CALIBRATION 55
9. APPENDIX A –USE WITH NON-MEDICAL ELECTRICAL EQUIPMENT 56

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D-0126050 rev 1 - 270+ Operating Manual
1.INTRODUCTION
1.1. THANK YOU
Thank you for purchasing an Amplivox 270+, a desktop-controlled audiometer that will give many years of
reliable service if treated with care.
1.2. INTENDED APPLICATIONS
This instrument is designed for use by trained personnel only, such as audiologists, ENT surgeons, doctors,
general practitioners, hearing aid dispensers, child health professionals and hearing healthcare professionals
with a similar level of education. It is not recommended to use the equipment without the necessary knowledge
and training.
The audiometer is capable of undertaking both air and bone conduction tests with or without masking, and has
many additional features such as the facility to support speech audiometry from live or recorded sources, the
option to select free field equivalent output from the headphones in speech mode and a range of clinical
audiometry tests.
1.3. CONTRAINDICATIONS
Always visually inspect the outer ear and the external auditory canal for abnormalities before testing.
Testing should not be performed on patients if the following conditions are applicable:
1. The presence of other sensitivity to loud sounds when high intensity stimuli are used.
2. Recent outer ear surgery.

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D-0126050 rev 1 - 270+ Operating Manual
1.4. STANDARD AND OPTIONAL ACCESSORIES
Shipping documentation will reference the stock number quoted below, and images of the parts alongside the
relevant stock number are available on the Amplivox website (www.amplivox.com). The required fitting
instructions are supplied with each part.
STANDARD ACCESSORIES
Model 270+ Audiometer
8514279
Audiogram cards (pack of
50)
8013007
Audiometric headset,
Earphones DD45 1
8517340
Operating Manual &
ampliSuite on USB stick
8517684
Bone vibrator headset B71
2
8517050
Carrying case
8004673
Mains adaptor
8512734
Cable USB –A & B
connector
8011241
Patient response switch 1
8011155
Calibration certificate
8011512
OPTIONAL ACCESSORIES
Masking monitor
earpiece 2
8507921
Audiocups add-on (noise
reducing earphone
enclosures) 1
8010855
Microphone and
monitor headset
8507435
Foam Eartips for Insert
Phones, standard, 50 each
8500090
MPT-II Printer
8503007
Foam Eartips for Insert
Phones, small, 50 each
8001772
Printer cable
8505753
Interconnect Stero Cable
Set
8510195
Insert phones IP301
8101884
SP90A speaker kit
8104162
Free field audio lead
8507853
Talk back microphone
8517741
1.5. WARNINGS
Throughout this manual, the following meanings of warnings and cautions apply:
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.
1
Applied part according to IEC60601-1
2
This part is not certified according to IEC 60601-1
WARNING
CAUTION

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D-0126050 rev 1 - 270+ Operating Manual
2.UNPACKING AND INSTALLATION
2.1. GENERAL
Please check the contents of the shipping carton against the delivery note to make sure that all items ordered
have been included. If anything is missing, please contact the distributor who supplied the audiometer or
Amplivox if purchased directly.
Please retain the carton and packaging as the instrument will need calibrating on an annual basis and should
be returned to Amplivox in its original shipping carton.
For supply in US only: Federal Law restricts this device to sale by or on the order of a licensed medical
professional.
2.2. MARKINGS
The following markings can be found:
Symbol
Explanation
Refer to instruction manual.
Definition: Type B applied part –an applied part providing protection against electric
shock, particularly regarding allowable patient leakage current and patient auxiliary
current.
The applied parts are the left & right earphones, bone vibrator, insert masker, patient
response switch and the associated cables.
WEEE (EU-directive)
This symbol indicates that when the end-user wishes to discard this product, it must be
sent to appropriate collection facilities for recovery and recycling. Failing to do so may
endanger the environment.
0123
The CE-mark indicates that Amplivox Ltd meets the requirements of Annex II of the
Medical Device Directive 93/42/EEC. TÜV Product Service, Identification No. 0123,
has approved the quality system.
Serial number.
Date of manufacture.
The output from the mains AC adapter is Direct Current.
CAUTION

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D-0126050 rev 1 - 270+ Operating Manual
Definition: Class II equipment –equipment in which protection against electric shock
does not rely on basic insulation only, but in which additional safety precautions such as
double insulation or reinforced insulation are provided, there being no provision for
protective earthing or reliance upon installation conditions.
Keep dry.
Transport and storage humidity range.
Transport and storage temperature range.
Logo.
Turns the instrument on or off. Long press to turn off. Short press to wake the device
from sleep mode (display off).
Operators live speech/external talkover microphone (3.5 mm jack)
Operators monitor earphone (3.5 mm jack)
Patient talkback microphone (6.35 mm jack)
Line Out for external amplifier (3.5 mm jack)
2.3. SAFETY INSTRUCTIONS
2.3.1. GENERAL
The following safety precautions must be observed at all times. General safety precautions must be followed
when operating electrical equipment. Failure to observe these precautions could result in damage to the
equipment and injury to the operator or patient.
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.
Amplivox Ltd is aware that safety rules within individual organisations vary. If a conflict exists between the
instructions in this manual and the rules of the organisation using this instrument, the more stringent rules
should take precedence.

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D-0126050 rev 1 - 270+ Operating Manual
The 270+ is intended to be used by hearing healthcare professionals (i.e. ENT doctors, audiologists), nurses
or technicians who have been trained in the proper use of the device.
2.3.2. CAUTIONS –GENERAL
If the system is not functioning properly, do not operate it until all necessary repairs are made and the unit is
tested and calibrated for proper functioning in accordance with Amplivox’s specifications.
Do not drop or in any other way cause undue impact to this device. If the instrument is damaged, return it to
the manufacturer for repair and/or calibration. Do not use the instrument if any damage is suspected.
This product and its accessories 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 should not
be used. Make sure all connections to external accessories are 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 Amplivox Ltd.
Equipment is not user repairable. Repairs must be performed by an authorised service representative only.
No modifications of the equipment are allowed by anyone other than a qualified Amplivox Ltd representative.
Modification of the equipment could be hazardous.
Amplivox Ltd will make available, on request, component part lists, descriptions, calibration instructions, or
other information that will assist authorised service personnel to repair those parts of this instrument that are
designated by Amplivox Ltd as repairable by service personnel.
No parts of the equipment can be serviced or maintained while in use with the patient.
Connect only accessories purchased from Amplivox Ltd to the 270+. Only accessories which have been stated
by Amplivox Ltd to be compatible are allowed to be connected to the device.
To comply with the standards IEC 60601-1 for safety and IEC 60601-1-2 for electromagnetic compatibility
(EMC) the audiometer is designed to be used only with the medically-approved mains adapter supplied, which
is specified as part of the equipment. Do not use any other type of mains adapter with this instrument.
The output from the mains adapter is fitted with electronic circuit protection. In case of overload the adapter
will shut down. When the fault is cleared the adapter will operate as normal. However, the input to the mains
adapter is protected with a non-replaceable fuse. If this fails the adapter will not operate.
The mains adapter is the mains disconnect device and therefore the audiometer should be positioned such
that easy access to the mains adapter is possible.
CAUTION

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D-0126050 rev 1 - 270+ Operating Manual
2.3.3. ENVIRONMENTAL FACTORS
Use and store the instrument indoors only. It is recommended that the instrument
be operated within an ambient temperature range of 15 °C / 59 °F to 35 °C / 95 °F
and in relative humidity between 30% and 90% (non-condensing).
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 an authorised service technician.
2.3.4. ELECTRICAL AND ELECTROSTATIC SAFETY
Before performing any service to the headphones or insert earphones you must
remove the 270+ transducers from the patient.
Do not touch the contacts on the back of the instrument and the patient at the
same time. The consequence could be a leakage current to the patient.
Do not open, modify or service the case of the instrument. Refer servicing to
qualified personnel.
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 must 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 –must comply with the
safety requirements stated in the general standard IEC 60601-1, (edition 3.1), clause 16. Any equipment not
complying with the leakage current requirements in IEC 60601-1 must be kept outside the patient environment
i.e. at least 1.5m from the patient support or must be supplied via a separation transformer to reduce the
leakage currents. Any person who connects external equipment to signal input, signal output or other
connectors has formed a Medical Electrical System and is therefore responsible for the system to comply with
these requirements. If in doubt, contact a qualified medical technician or your local representative. When the
instrument is connected to a PC, or other similar item, beware of not touching the PC and patient
simultaneously.
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, 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.
Do not use any additional multiple socket-outlet or extension cord. Use only the Amplivox Mains Power
Adaptor.
2.3.5. ELECTROMAGNETIC COMPATIBILITY (EMC)
Although the instrument fulfills the relevant EMC requirements, precautions
should be taken to 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 disturbance appears. Please also refer to the
appendix regarding EMC.
CAUTION
WARNING
CAUTION
CAUTION

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D-0126050 rev 1 - 270+ Operating Manual
2.3.6. EXPLOSION HAZARDS
Risk of explosion.
Do NOT use in the presence of flammable anesthetics or other gases.
Do NOT use in the presence of flammable gaseous mixtures. Users should
consider the possibility of explosions or fire when using this device in close
proximity to flammable anesthetic gases.
Do NOT use the 270+ in a highly oxygen-enriched environment, such as a
hyperbaric chamber, oxygen tent, etc.
2.3.7. MEASURING ACCURACY
To guarantee that the 270+ works properly, the instrument should be checked and calibrated at least once a
year. The transducers supplied with the audiometer are specifically calibrated with it; if these transducers are
changed recalibration will be required.
The service and calibration must be performed by an authorised service technician. If these checks are not
performed, EU Medical Device Directive (MDD) and other regulations may be violated and warranties may be
void.
The use of non-calibrated devices can lead to incorrect test results and is not advisable.
2.3.8. MISCELLANEOUS
Please note: DO NOT connect the 270+ hardware to the computer before the software has been installed.
Storage in temperatures below 0C /32F and above 50C /122F may cause permanent damage to the
instrument and its accessories.
Do not place the instrument next to a heat source of any kind.
Great care should be exercised when handling transducers, as rough handling, for example dropping onto a
hard surface may break or damage the parts.
Within the European Union it is illegal to dispose of electrical and electronic waste as unsorted
municipal waste. Electrical and electronic waste may contain hazardous substances and
therefore have to be disposed of separately. Such products will be marked with the crossed-
out wheelie-bin image shown to the left. User cooperation is important in order to ensure a
high level of reuse and recycling of electrical and electronic waste. Failure to recycle such
waste products in an appropriate way may endanger the environment and consequently the
health of human beings.
Outside the European Union, local regulations should be followed when disposing of the product after its end
of life.
2.3.9. USE OF EQUIPMENT AFTER TRANSPORT AND STORAGE
Please make sure that the instrument is functioning correctly before use. If the instrument has been stored in
a cold environment (even for short period of time), please allow the instrument to become acclimatised. This
can take a long time depending on the conditions (such as environmental humidity). You can reduce the
condensation by storing the instrument in its original packaging. If the instrument is stored under warmer
WARNING

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D-0126050 rev 1 - 270+ Operating Manual
conditions than the actual use conditions no special precaution is required before use. Always ensure proper
operation of the instrument by following routine check procedures for audiometric equipment.
2.3.10. MAINS SUPPLY OPERATION
The audiometer is designed for continuous operation and is powered by a mains adapter which is supplied
and specified as part of the equipment. If a replacement is required, please contact your Amplivox distributor.
All other connections must be made before connecting the output lead from the adapter into the POWER input
socket on the back of the audiometer. Switch on the mains supply - the POWER indicator on the audiometer
will illuminate green, showing that the instrument is ready for use.
The output from mains adapter is fitted with electronic circuit protection. In case of overload the adapter will
shut down. When the fault is cleared the adapter will operate as normal. However, the input to the mains
adapter is protected with a non-replaceable fuse. If this fails, the adapter will not operate.
The mains adapter is the mains disconnect device and therefore the audiometer should be positioned such
that easy access to the mains adapter is possible.
2.4. CONNECTIONS
All connections are made to the rear panel of the audiometer as shown below.
1
MIC 1
3.5 mm jack
Operators Live Speech/External Talkover Microphone
2
Monitor
3.5 mm jack
Operators Monitor Earphone
3
Bone (Grey)
6.3 mm jack
Bone Vibrator Headset
4
Insert
3.5 mm jack
Masking Earphone
5
Right (Red)
6.3 mm jack
Air Conduction Headset (Right Ear)
6
Left (Blue)
6.3 mm jack
Air Conduction Headset (Left Ear)
7
MIC 2
3.5 mm jack
Patient Talkback Microphone
8
Power
2.5 mm DC jack
Mains AC/DC Adapter
9
Response (Black)
6.3 mm jack
Patient Response Switch
1 2 3 4 5 6 7 8 9 10 11 12 13

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D-0126050 rev 1 - 270+ Operating Manual
10
Line IN
3.5 mm jack
CD / Tape Player /MP3
11
Line OUT
3.5 mm jack
External Amplifier
12
Data
6 pin mini DIN
Printer
13
USB
USB connector
Computer (via USB port)
Please note: Only connect the accessories supplied with the instrument or supplied by Amplivox or an
Amplivox distributor. These parts have been tested for use with the Amplivox 270+ audiometer for compliance
with the standards IEC 60601-1 and IEC 60601-1-2. The use of accessories other than those specified may
compromise compliance with these standards.
2.5. CONTROLS AND INDICATORS (BASE UNIT)
The 270+ consists of an LCD screen, three button groups in total to operate the instrument and three status
LEDs.
a
Response light
When the patient response switch is pressed, the light will illuminate green.
b
Tone presentation
When a signal is presented to the patient, the light will illuminate green.
c
VU meter
Indicates speech level
d
Light ring left
Indicates selected test ear
e
Light ring right
Indicates presentation on contralateral test ear
a
c
b
d
a
e
12
13
11
1-10

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D-0126050 rev 1 - 270+ Operating Manual
1
Clear
Clears all displayed test results
2
Signal
Switch between tone and speech testing
3
Ear
Change ear
4
Mask
Activate masking
5
Output
Select transducer to present signal
6
> 100 dB
Test above 100 dB
7
Auto
Start auto test
8
Special
Select special test
9
Menu
Change instrument settings, save and reload tests
10
Power
Switch device on or off
11a
Frequency
Decrease and increase test frequency
In Speech Assessment used for ‘Yes and No’
11b
Talkover/Talkback
Pressing both frequency buttons to activate talkover and talkback
12
Present
Present test stimulus
13
Store
Save measured point
2.6. LIGHT INDICATORS
The indicators on the 270+ show the status of the selected ear and test mode.
LIGHT
LIGHT RING LEFT
LIGHT RING RIGHT
Red light: Right ear selected as test ear.
Blue light: Left ear selected as test ear.
White light: Masking
Blue and white lights: Both channels active.
2.7. HARDWARE INSTALLATION
Connect the relevant transducers, the patient response switch and, if used, the speech and freefield with the
device, before connecting the power adapter.
The instrument is designed for continuous operation and is powered by a mains adapter. Connect the output
lead from the adapter into the POWER input socket on the back of the 270+.

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2.8. THE SANIBEL MPT-II PRINTER
2.8.1. INSTALLING THE SANIBEL MPT-II PRINTER
The Sanibel MPT-II thermal printer is available as an option for use with the 270+ and is connected using the
cable supplied. The printer may be specified when ordering and only this printer should be used. It will be
correctly configured for use.
1. Open the lid by pushing on the sides, insert paper roll as shown,
2. and close the lid.
3. Insert the battery.
2.8.2. SWITCHING THE PRINTER ON AND OFF
Push POWER BUTTON for two seconds in order to power ON or OFF. One
short beep will be heard at power ON, two short beeps at power OFF.
The green power indicator will be lit if the printer is powered by battery.
2.8.3. USING THE PRINTER
Printer self-test:
While printer is powered OFF, press and hold PAPER FEED button, then press
and hold POWER BUTTON simultaneously. When beep is heard after approx. 3
seconds, release both buttons, and a test page will print with information on current
status and character samples.
Paper feed:
When powered, press PAPER FEED button. Paper will feed as long as the button
is pressed.
Connecting
process:
•Connect the printer via the cable with the device
•Power on printer
•Select print option in 270+
Please note: Do not have several printers powered on and within range while
searching.

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3.PRINCIPLES OF OPERATION
3.1. OTOSCOPIC EXAMINATION
A suitably-qualified health care professional should perform a thorough otoscopic examination to establish that
the condition of the ear is suitable for the test options selected and that no contraindications are present. The
latter would include obstruction of the external ear canal due to excessive wax and/or hairs, both of which
would need to be removed. This is required to ensure that the pure tone delivered by the earphone is able to
reach the ear drum and is not reflected by cerumen or debris and thereby alter the test result.
3.2. PRINCIPALS OF PURE TONE AUDIOMETRY
Ideally, hearing tests are conducted in a soundproof room. The purpose of pure tone audiometry is to measure
the patient’s hearing threshold which is then compared to the hearing threshold of an average normal hearing
person. The examination starts with air conduction on the ear with better hearing, or if not specified differently,
on the right ear. The BSA (British Society of Audiology) recommends starting the test at 1000 Hz to then next
measure the higher frequencies. When done with the high frequencies 1000 Hz shall be retested and to then
continue with the lower frequencies. When air conduction is completed, bone conduction is performed.
In cases of unsymmetrical hearing, it might be required to mask the air and bone conduction in order to prevent
hearing the test tone on the opposite ear. This phenomenon is called ‘crossover’ and occurs more often while
testing bone conduction then air conduction.
3.3. PRINCIPALS OF SPEECH AUDIOMETRY
Speech audiometry has become a strong tool to assess hearing loss. In addition to pure-tone audiometry, the
degree and type of hearing loss can be determined and further information about word recognition and
tolerance to speech stimuli can be identified. Also, speech audiometry is used to fit hearing aids or other
amplifying devices.
3.4. PRINCIPALS OF FREEFIELD AUDIOMETRY
Speech audiometry is often conducted in a freefield audiometry setup, to evaluate the use and benefit of
hearing aids for the patient.

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4.USING THE 270+
4.1. GENERAL PRECAUTIONS
When operating the instrument, please observe the following general precautions:
1. Use this device only as described in this manual.
2. Be sure to use only stimulation intensities acceptable to the patient.
3. Clean the headphones, insert phones and patient response switch regularly using a recognised
disinfectant.
4. The presence of tinnitus, hyperacusis or other sensitivity to loud sounds may contraindicate testing
when high intensity stimuli are used.
Please note:
Careful handling of the instrument whenever in contact with a patient should be given high priority. Calm and
stable positioning while testing is preferred for optimal accuracy.
1. Never clean the transducer housing with water or insert non-specified instruments into the transducer.
2. Do not drop and avoid other undue impact to this device. If the instrument is dropped or in any other
way damaged, return it to the manufacturer for repair and/or calibration. Do not use the instrument if
any damage is suspected.
4.2. SWITCHING THE INSTRUMENT ON AND OFF
Select the on/off button for 1 second to switch the instrument on. The display will briefly show
the model and the type of headphone currently selected for use. No warm-up time is required,
although a short diagnostic routine will run for a few seconds.
To switch the instrument off again, hold the button for approx. 2 seconds and the instrument
will turn off.
4.3. SWITCHING HEADPHONES
If a secondary headphone has been enabled (e.g. IP30 together with DD45) it will be necessary to select the
required headphone as follows: Select MENU and move to the item SELECT OUTPUT.
Select the headphones to be used with the audiometer with the softkeys F1 and F2. Confirm your selection by
pressing softkey F4 (SAVE).
CAUTION

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D-0126050 rev 1 - 270+ Operating Manual
4.4. OPERATING LANGUAGE
The instrument will be set in English by default.
To select the operating language for the audiometer (English or German) continue to hold the
power button when switching on.
An additional display will allow the selection of English (F1) or Deutsch (F2). After selecting a
language, the start-up screen will show.
4.5. SYSTEM INFORMATION
The system information is briefly displayed when switching on the 270+ unit.
Information about the firmware version (as in image above 1.3.2.1), the model (270+) and the type of
headphone currently selected for use.

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D-0126050 rev 1 - 270+ Operating Manual
4.6. FUNCTION BUTTONS
4.6.1. PRESENTING A TONE
The presentation button is located to the right of the Channel 1 rotary
control. The button is conductive, by touching it the test signal will be
presented to the patient (presentation mode) or interrupted (continuous
mode).
4.6.2. STORING A TEST POINT
The store button is located to the left of the Channel 2 rotary control. The
button is conductive, by touching it the current test level and frequency will
be stored to the temporary memory of the device.
4.6.3. TALKOVER AND TALKBACK
Pressing both frequency buttons at the same time, will bring you to the
talkover and talkback screen.
For talkover (you use this to talk to the patient), the internal or an external
headset can be used.
Please note: It is not possible to use both an external and an internal
microphone at the same time. The used microphone needs to be defined
via the settings. Select MENU and CONFIG. to choose if the external
microphone shall be used instead of the built-in microphone.
When pressing both frequency buttons, the screen will show the talkover and talkback screen. Talkover is
active as soon as the buttons are both pressed. The level of talkover can be controlled with the Channel 1rotary
control.
When starting up the unit, talkback is switched off and needs to be activated manually every time the device
is started up. Use F4 to activate talkback. The function will now be enabled during the entire operation of the
device. Use the Channel 2 rotary control to control the talkback level in your monitor headset.