MA 53 Operating Instructions Feb 2007

MAICO

Operating Instructions MA 53

Table of Contents Page 1. Introduction 2 2. Description 3 3. Getting started 5 3.1 Unpacking your instrument 5 3.2 Preparing the MA 53 for use 6 3.3 Getting familiar with your MA 53 7 3.3.1 Using the keyboard of the MA 53 8 3.3.2 The display of the MA 53 9 4. Pure tone audiometry 11 4.1 Air Conduction (AC) Testing 11 4.2 Uncomfortable Hearing Level (UCL) Testing 12 4.3 Bone Conduction (BC) Testing 13 4.4 Masking of the opposite ear 14 4.5 Diagnostic Tests 16 4.6 Dual Frequency Mode 21 4.7 High Frequency Audiometry (optional) 22 6. Speech Audiometry 23 6.1 Connecting the speech source (microphone, tape or CD-Player) 23 6.2 Speech Calibration 24 6.3 Connection and adjustment of the monitor phone 25 6.4 Speech Audiometry 26 6.5 Masking 27 7. Advanced features 28 8. Quick reference guide 31 9. Recommended literature 36 10. Computer interface 37 11. Care and Maintenance of the instrument 38 12. Trouble shooting 39 13. Technical data 40 14. Warranty, Maintenance and After-Sales Service 47 15. Safety Regulations 48 16. List for subjective instrument check 49 17. Certificate of conformity 50 18. Front panel layout and rear panel connections 52

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Operating Instructions MA 53

1 Introduction Thank you very much for purchasing a quality product from the MAICO family. The MA 53 audiometer is manufactured to meet all quality and safety requirements, and has been certified with the CE-symbol according to Medical Directive 93/42/EEC. In designing the MA 53 we placed particular importance in making it a userfriendly device, meaning its operation is simple and easy to understand. All builtin test signals are generated by a digital signal processor (DSP) which allows to implement new test signals just with a software upgrade. And because MA 53 functions are software controlled, upgrading later to new, extended measurement functions will be simple and inexpensive. That means that you have invested in a device that will correspond to your future needs. This user manual should make it as easy as possible for you to become familiar with the functions of the MA 53. Please open out the flap of illustrations on the last page. The description of the position (e.g. ! ) of controls, displays and connections, found again in the text, will make it easier for you to learn how to operate the MA 53. If you have problems or have ideas for further improvements, please get in touch with us. Simply call. Your MAICO-team

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Operating Instructions MA 53

2 Description The MA 53 is a real two-channel audiometer for advanced pure tone and speech audiometric tests. It can be used for ENT diagnostics and hearing aid fittings in the office, and for mobile audiometry in clinics, homes and aboard. Tests can be performed using the TDH 39 headphones (AC), the optional high frequency headphones HDA 200, B 71 bone conduction receiver (BC) or optional insert phones and loudspeakers (FF). Built-in test signals are pure tone, pulse tone, warble tone, narrow band and broadband noise. All signals and test frequencies are individually adjustable on both channels. The MA 53 has stereophonic microphone inputs for live speech audiometry, an input for an optional tape/CD player with speech test material and an additional input for a second tape/CD player (i.e. for external masking signals). The MA 53 audiometer with the standard TDH 39 delivers 12 air conduction (AC) test frequencies from 125 Hz to 12 kHz, with levels from -10 dBHL to 120 dBHL. With the optional high frequency HDA 200 it delivers 17 air conduction (AC-HF) test frequencies from 125 Hz to 16 kHz, with levels from -20 dBHL to 120 dBHL. Bone conduction (BC) can be tested with 11 test frequencies from 125 Hz to 8 kHz with levels from -10 dBHL to 70 dB HL (with the standard bone conductor B 71 the frequency range is limited from 250 Hz to 6 kHz). The optional insert phones EAR 3A submit levels from -10 dBHL to 120 dBHL with 11 test frequencies from 125 Hz to 8 kHz. Optional loudspeakers are available for free sound field measurements (FF). The new, portable loudspeakers MAICO SBC have a dynamic range from -10 dBHL to 80 dBHL at 1m distance, for nine test frequencies from 500 Hz to 8 kHz. The frequency range for speech is 500 Hz to 8 kHz with levels up to 80 dBSPL. The loudspeakers Canton Plus XL (not available in the USA), deliver levels up to 90 dBHL at 1m distance over the entire frequency range from 125 Hz to 8 kHz. The MA 53 has also separate line level outputs for an external amplifier. The hearing level is controlled independently for each channel by two detented dials on the left and right of the instrument which can be operated from the side or the top. The level steps are 5 dB and can be changed to 2 dB or 1 dB. The signal STIM bar and the frequency up/down keys are just beside the level control knobs for easy one handed control of level, frequency and signal presentation. The large backlighted LCD-display shows level, frequency, transducer, signal and other information for each channel. Geba53_e.03.b.wpd

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Operating Instructions MA 53

As a result of modern microprocessor technology, the MA 53 is easy to use and is extremely reliable. The audiometer is designed to be extremely service friendly. Automatic test programs make trouble shooting and the yearly calibration as easy as possible. PC-Interface: A serial RS 232C interface for data transfer to a connected computer is built in. The optional MAICO-audiometry module for NOAH and PAX enables the automatic data transfer of all test results of the MA 53, like speech audiogram and ABLB, DLI, SISI, tone decay etc. For more information see chapter 10.

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Operating Instructions MA 53

3 Getting started 3.1 Unpacking your instrument Your MA 53 was carefully inspected and packed for shipping. However, it is a good practice to thoroughly inspect the outside of the shipping box for signs of damage. If any damage is noted, please notify the carrier immediately. Carefully remove the instrument from the shipping box. Remove the plastic bag from the instrument and inspect the case for any damage. Notify the carrier immediately if any mechanical damage is noted. This will assure that a proper claim is made. Save all packing material so the claim adjuster can inspect it as well. Notify your dealer or MAICO when the adjuster has completed the inspection. SAVE ALL THE ORIGINAL PACKING MATERIAL AND THE SHIPPING CONTAINER SO THE INSTRUMENT CAN BE PROPERLY PACKED IF IT NEEDS TO BE RETURNED FOR SERVICE OR CALIBRATION. All accessories are already packaged in the compartment connected with the MA 53. Please check that all accessories listed below are received in good condition. If any accessories are missing or damaged, immediately notify your dealer or MAICO. Standard accessories: 1 Headphone TDH 39 1 Bone conduction receiver B 71 with headband 1 Patient resonse switch 1 power cable 1 microphone with stand (only for export outside USA) 1 audiogram form (50 sheets) 1 monitor headset with microphone (USA only) 5 sound room cords (USA only) Calibration of the device: The instrument, headphones, bone conduction receiver as well as the optional insert phone and loudspeaker match one another and have the same serial number (e.g. 6631520). As they have been calibrated with this particular instrument, using of other transducers is not allowed. If one of the acoustic transducers is replaced, the instrument must be recalibrated. The use of non-calibrated audiometers leads to incorrect measurements!

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3.2 Preparing the MA 53 for use The MA 53 with its integrated compartment for the accessories is perfect for portable use. The rugged housing, light weight and the comfortable handling make it easy and convenient to transport the instrument. Carry it, as shown, with the bottom away from the leg. That helps protect the front cover from damage, and due to the asymmetrical handle position it provides more space for your leg. To get started first move the handle under the housing. Unlatch the cover by pressing in the two black locks located on the left and right sides near the Picture 1 Transport of MA 53 front of the instrument. Open the front cover and rest it on the back cover of the accessory compartment. To open the compartment, press the two black locks in the upper middle of the instrument. Open the compartment cover as seen in picture 2. Take the headphone, the bone conduction receiver, the patient response switch and the microphone out of the compartment and connect the power cable to power. The MA 53 operates with voltages from 100 to 240 V~ AC, 50/60 Hz. To avoid pinching the cables when closing the cover, lay the cables in the slots Picture 2 MA 53 with open cover provided. Close the back cover and latch it with slight pressure. You can place the microphone or a tape or CD-player on top of the cover (see picture 3). The MA 53 should be operated in a quiet room, so that the audiometric examinations are not influenced by outside noises. For use in noisier environments headphones with optional sound insulation muffs are available. Electro-medical instruments, which emit strong electromagnetic fields (e.g. microwaves - radiotherapy devices), can influence the function of the audiometer. Therefore the use of these instruments is not allowed Picture 3 MA 53 in operation in close proximity to the audiometer. The test room must be at normal temperature, usually 15/C/ 59/F to 35/C / 95/F, and the instrument should be switched on about 10 minutes before the first measurement to guarantee precise measuring results. If the device has been cooled down (e.g. during transport), please wait until it has warmed up to room temperature. Geba53_e.03.b.wpd

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3.3 Getting familiar with your MA 53 Turn on the instrument with the power switch " which is located at the right side of the MA 53. The device performs its initial test and autocalibration. If an error is detected the test is stopped and a description of the error is shown on the LCDdisplay #. In this case please contact your local dealer or service. If the test is passed, the instrument is MAICO setup to air conduction and pure tone. The corresponding LED's above the 17 receiver selectors $ and % and the 8 10 16 18 26 signal selectors & and ' are lighted. The frequency is set to 1 kHz and the Picture 4 MA 53 power switch, display and level to 30 dBHL for both channels. All selection buttons for left and right channel these settings are also shown on the display # (see picture 5). HL The hearing level can be easily adjusted 30 dB L 1000 Hz R 30Air dB independently for each channel with a Air Tone Tone knob ( and ) on each side of the instrument. For optimal convenience these level control knobs are usable from the top or the side of the Picture 5 MA 53 display with initial settings instrument. They are detented in 5 dB steps (adjustable to 2 dB or 1 dB). The signal STIM bars * and + are located beside the level control knobs (, ). The signal LED's , and - light up when the signal is presented. You can change from presenter to interrupter function with the STIM MODE button .. The corresponding LED lights when the interrupter is selected. The frequency is changed with up /, 0 and down !, 1 buttons for both MAICO channels. The design of the MA 53 makes it easy to control level, signal 1 3 5 13 21 23 25 2 4 22 24 presentation and frequency with one hand. Picture 6 MA 53 level and frequency control L

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STIM

STIM

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3.3.1 Using the keyboard of the MA 53 All main functions of the MA 53 are directly accessable by pressing a single button. Not frequently used procedures like the calibration of the speech source or the level step selection are hidden as a “second level function”. To select this function just press the addressed button more than two seconds. A user menu for the customization of the MA 53 is available for advanced users (see chapter 8). Please find below the description of the main and second level functions of each button: / left (blue) channel frequency up: change to next higher frequency L

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STIM

STIM

Press the frequency up and down buttons simultaneously to enter / exit the dual frequency mode

PAT

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INSERT FF BC AC

Talk Over

PULSE

NOISE MIC TAPE TONE

SWAP

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NOISE MIC TAPE TONE

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INSERT FF BC AC

Talk Over

change to next lower frequency Press the frequency up and down buttons simultaneously to enter / exit the dual frequency mode

2 left (blue) talk over microphone:

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switches on the talk over microPicture 7 MA 53 keyboard phone as long as the button is pressed. The level can be adjusted with the knobs ( or ). The actual value is displayed in dBHL at the lower center of the LCD-display #. $ left (blue) channel receiver selector: changes the receiver from AC to BC or FF or INSERT (if option assembled). The lighted LED above shows the current selection. 2nd level: selects test mode HL, UCL, MCL for selected receiver (see chapter 4.2)

3 FM - modulation (warble tone): changes test signal from pure tone to warble tone. 2nd level: to enter the user menu press button during power on.

& left (blue) channel signal selector: changes the test signal from pure tone to tape/CD or microphone or noise or switches the channel off. 2nd level: calibration of tape/CD or live voice microphone (see chapter 6.2)

4 pulse tone: enables pulsing of pure tone or warble tone. 2nd level: enter pulse tone menu: ABLB, DLI and SISI Test (see chapter 4.5)

. stim mode: changes the signal presentation from presenter to interrupter mode. 2nd level: enables interlock function. Pressing left * or right + signal presentation bar Geba53_e.03.b.wpd

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affects both channels.

5 swap function: exchanges the outputs for both ears (i.e. the right controls now affect the left ear). 6 tracking function: enables the automatic tracking (see chapter 4.4 Masking). 2nd level: enters level step selection menu. The actual level step is displayed at the lower center of the LCD-display #. Choose the level steps with the frequency up/down buttons 1and 0

' right (red) channel signal selector key: changes the test signal from pure tone to tape/CD or microphone or noise or switches the channel off. 2nd level: adjustment of talkback microphone and monitor phone (see chapter 6.2)

% right (red) channel receiver selector: changes the receiver from AC to BC or FF or INSERT (if option assembled). The lighted LED above shows the current selection. 2nd level: selects test mode HL, UCL, MCL for selected receiver (see chapter 4.2)

7 right (red) channel talk over microphone: switches on talk over microphone as long as the button is pressed. The level can be adjusted with the knobs ( or ). The actual value is displayed in dBHL at the lower center of the LCD-display #. 1 right (red) frequency down: changes to next lower frequency 0 right (red) frequency up: changes to next higher frequency

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Picture 8 MA 53 keyboard

3.3.2 The display of the MA 53 HL 70 dB L 1500 Hz R 90 dB The large backlighted graphical LCD- Bone Warble Air NB-Noise Display # of the MA 53 shows all Tone Tracked Talk Over actual settings and test results. The 70 dB display area is split with a line into an upper or main area and a lower or Picture 9 MA 53 display for BC-test advanced area (see picture 9). The main area shows the individual settings for the left channel on the left and the right channel on the right. General settings which affect both channels are displayed in the middle. The example picture 9 shows a typical setting for a BCGeba53_e.03.b.wpd

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threshold test. The left channel is bone conduction with 70 dBHL , tone and tracking function enabled. The right channel is set to 90 dBHL narrow band noise with air conduction for masking. The test frequency is 1500 Hz and the test signal is a warble tone. The lower section of the display shows that the talk over microphone button 2 or 7 is pressed SRT and the audiologist talks to the patient 60 dB L 60% R 60 Air dB Correct: 6 with 70 dBHL. The HL in the upper row Air Tape/CD Wrong: 4 Speech-Noise before 1500 Hz indicates that the current measurement is stored as Hearing Level (threshold) test. Picture 10 MA 53 display for speech test Picture 10 shows the display for a speech test with speech test material from tape or CD of the left ear and masking of the opposite ear. The left part of the LCD-display # shows the settings for the left channel: level = 60 dBHL, receiver = AC, signal = tape/CD. The middle of the LCD-display # shows the actual test and the result: MS stands for multi syllable speech test, speech discrimination = 60%, correct words = 6, wrong words = 4. The right part of the LCD-display #shows the setting for the right channel: level = 60 dBHL, receiver = AC, signal = speech-noise (masking). The LCD-display # has an energy saver function: the backlight of the display is automatically switched off after approximately three minutes. Any action with the MA 53 such as pressing a button or turning the knobs switches the backlight on again immediately.

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4 Pure tone audiometry 4.1 Air Conduction (AC) Testing In the hearing threshold test, the hearing threshold of the patient is measured in comparison to the normal hearing threshold for air conduction. The test is started on the ear with better hearing. The patient should sit at a distance of at least 1 m from the device. Eliminate any obstructions which will interfere with the placement of the earphone cushions on the ear (i.e. hair, eyeglasses). Ensure that the headphones are put on correctly. Red side on the right, blue side on the left. Adjust the headband of the headphones so that the receivers are at the correct height (the sound output grid 8 exactly facing the ear canal). Start with the “better” ear at 1 kHz. (After switching on, the frequency is automatically set to 1 kHz.) In the following example we assume that the left is the Picture 11 Headphone “better” ear. Set the receiver selector $ to AC and the signal selector & to TONE. Set the left level control knob ( to a value just below expected hearing loss. Explain to the patient that he should press the button of the patient response switch if he just hears the test tone. Press the STIM bar * for a certain time to present the test tone. The STIM LED , should light on. If the patient hears the test tone, the patient response display MAICO lights red. In this case decrease the level with the level control 1 3 5 9 11 8 10 12 k n o b ( . P r o c e e d wit h 2 4 presenting the test signal as Picture 12 MA 53 controls and display for air conduction threshold test of the left ear described before. If the patient doesn't hear the test tone, increase the level with the level control knob (. Proceed with presenting the test signal as described before. L

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STIM

STIM

PAT

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FM

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Talk Over

INSERT FF BC AC

NOISE MIC TAPE TONE

PULSE

SWAP

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TRACK

NOISE MIC TAPE TONE

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When you find a stable threshold value, note the level and frequency. If the MA 53 is connected to a PC, the value was stored with your last STIM presentation. Test through the frequencies. Starting at 1 kHz, set the higher frequencies first then the lower frequencies. Use the frequency up key / or 0 to select the higher frequencies and use the frequency down ! or 1 to select the lower frequencies. Select the next frequency, increase the level again and proceed with presenting the test signal as described before. Once all frequencies are tested choose the poorer ear and repeat the hearing threshold test. You can do this with the corresponding controls on the other side or just by pressing HL the SWAP button 5. The SWAP 60 dB R 1500 Hz L 30 Air dB Warble function enabled means that you Air Tone Pulse Tone measure the right ear using the controls on the left side. The ouput to the left and right earphones are exchanged. Also, Picture 13 MA 53 display for AC-test with the left and right display text is enabled SWAP function, Pulse and Warble tone exchanged (see picture 13). The correct marks in an audiogram are: O (red) = right and X (blue) = left Pulse tone: If required, the test can also be performed with a pulsed tone. Press the PULSE button 4 and the pure tone will be switched 0.25s on and 0.25s off. Warble tone: If required, the test can also be performed with a warble tone. Press the FM button 3 and the pure tone will modulate frequency. The warble tone can also be pulsed as described before. For hygienic reasons it is important to clean the ear cushions of the headphone (see chapter 11). 4.2 Uncomfortable Hearing Level (UCL) Testing Testing of UCL can be measured using pure tone stimuli or speech (live voice or tape/CD). The purpose is to determine the dB level at which the stimuli becomes uncomfortable to the patient. This information is valuable for determining the patient's upper dynamic range limit for proper hearing aid fittings and for determining symptoms of recruitment. Warning! Because this test uses high sound pressure levels, it is extremely important to perform this test using the utmost caution to avoid damaging the ear. To prevent the possibility of extreme discomfort by the patient, it is important to start the test with levels near the patient‘s MCL (Most Comfortable Level). Geba53_e.03.b.wpd

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The UCL level is described as the level between very loud and loud perception of the test signal. Press the receiver selector button UL $ or % longer than 2 seconds. Air60 dB L 1000 Hz R 30 Air dB Tone The LCD-display in the upper row Tone changes from HL to UL (see picture 14). Start as described in chapter 4.1 Picture 14 MA 53 display for UCL-test left with a test level of 60 dBHL. Present the tone briefly (max. 1s). If the signal was recognized by the patient as not uncomfortable increase the level and proceed as described before. If the signal was uncomfortable for the patient note the values. Proceed accordingly with other test frequencies. For hygienic reasons it is important to clean the ear cushions of the headphone (see chapter 11). 4.3 Bone Conduction (BC) Testing Bone conduction, i.e. the transmission of sound waves through the skull directly to the inner ear conveys information about the function of the inner ear. For a neural hearing loss the values of air conduction (chapter 4.1) and bone conduction are the same. In this case a hearing Picture 15 Bone conductor loss of the middle ear can be eliminated. Place the bone conduction receiver so that the flat, circular side of the transducer Y is placed on the mastoid, at the noticeable ledge of the cranial bone behind the auricle (see picture 16). The other side of the headband is placed in front of the opposite ear. Set the receiver selector $ or % to BC and the signal selector & or ' to TONE. Perform the test the same way as for air conduction (see 4.1). Enter the measurements for all frequencies on the form, connect all points with dotted lines Picture 16 Correct seating marked on the audiogram form as follows: of the bone conductor

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> = right and < = left For hygienic reasons it is important to clean the bone conductor (see chapter 11). 4.4 Masking of the opposite ear The basics of masking are explained below. To begin testing immediately, please go directly to 4.4.3 Manual masking. 4.4.1 Crossover: When measuring a pure tone audiogram you assume that the measured hearing threshold is correct. But if you recognize that sound is also transmitted through bone conduction over the entire skull it is probable that the opposite ear has also received sound. This is called “crossover”. Crossover can also occur when measuring air conduction because the test tone is received by the skull and transmitted by bone. Whether the crossover signal can be heard by the opposite ear depends on its inner ear function. Relevant to crossover is the sound level which is received by the opposite ear. The difference between the original test signal at the test ear and the received signal at the opposite ear is called “interaural attenuation”. For bone conduction measurement the interaural attenuation is 0 to 15 dB. Bone conduction crossover is therefore possible even with a slight difference in hearing loss between ears. Important: Please advise the patient to tell you in which ear he hears the test signal. It is thereby easier to detect crossover. 4.4.2 Masking theory: To ensure that the patient will not experience crossover you must mask the opposite ear. Masking increases the hearing threshold of the opposite ear. The masking is done with a noise signal which is transmitted by the headphone. For pure tone audiometry a narrowband noise is used. This noise changes its center frequency according to the frequency of the test signal. 4.4.3 Manual masking: If you have to mask use the common masking rules. See chapter 9 for recommended literature. Masking is an important part of practical audiometry. It is necessary to be familiar with this topic to avoid errors which would lead to a wrong diagnosis. -

For the opposite ear set the receiver selector $ or % to AC and the signal selector & or ' to NOISE.

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Adjust the required masking level with the level control knob ( or ). Notice that the masking sound is continuously presented for effective masking. You can interrupt the masking signal by pressing the corresponding interrupter key * or +. To mask when performing bone conduction testing, place the headphone on the opposite ear so that the receiver is at the correct height (the sound output Picture 17 Headphone grid 8 exactly faces the ear canal). Adjust the headband of the headphones. The receiver on the side where the bone conductor is placed should be seated directly on the cheek bone. The marking for air conduction with masking should be done with the symbols 9 = the right side and : = the left side on the audiogram form. The marking for bone conduction with masking should be done with the symbols [ = the right side and ] = the left Picture 18 Correct seating side on the audiogram form. of the bone conductor

4.4.4 Automatic masking: With the manual masking, as described before, you have to readjust the masking level every time you change the test signal level. The MA 53 has a tracking feature for easy masking. Adjust the test signal using the HL 45 dB L 1000 Hz R 65 Air dB level control knob ( or ), then Bone NB-Noise with the opposite level control Tone Tracked knob ) or ( adjust the corresponding masking level. Now press the TRACK button 6. Picture 19 MA 53 display for bone conduction The masking level is automatically with masking and enabled tracking function changed if you adjust the test signal level (e.g. if the test level was 30 dB and the masking level 50 dB and if you change the test level to 45 dB the masking level is automatically adjusted to 65 dB).

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4.5 Diagnostic Tests 4.5.1 Suprathreshold tests The MA 53 offers additional suprathreshold tests which can offer more information about the kind of the hearing loss. To access suprathreshold tests HL 1000 Hz R 30 Air dB press the PULSE button 4 longer Air70 dB L Tone than two seconds. The Tone suprathreshold test menu is now ABL 0.5 1.0 sec SISI DLI 4.0 3.0 2.0 1.5 1.0 0.5 dB displayed on the lower part of the LCD-display # (see Picture 20 MA 53 display with picture 20). The actual choice is suprathreshold menu displayed inversely. You can toggle through the different options by briefly pressing the PULSE button 4. Start the chosen option by pressing the STIM bar * or +. 4.5.1.1 The ABLB (Fowler) Test The Alternate Binaural Loudness Balance test is a recruitment test which uses the presentation of alternating tones between the two ears with headphones. The intensity of the tone in the hearing-impaired ear is varied until the loudness of the tone is judged by the patient to be equivalent to a tone at a constant intensity in the normal ear. This is called loudness balance. The test is done for various intensity levels in the normal ear. To start the test select 0.5 sec. or 1 sec. modulation time in the suprathreshold menu (as decribed before under 4.5.1) and press the STIM bar * or +. On the LCD-display # ABL is HL 2000 Hz R 50 Air dB shown with the chosen modu- Air50 dB L Tone ABL 0.5 s Tone lation time (see picture 21). Adjust the desired hearing levels for both the normal ear and the impaired ear using the level Picture 21 MA 53 display with ABLB test control knobs ( and ). Press the STIM MODE button . to present the signal continuously. Now change the level for the hearing-impaired ear with the level control knob ) or ( until the patient indicates that the loudness in both ears is equal. Note the levels and proceed with other levels and frequencies as required. To exit the test briefly press the PULSE button 4.

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4.5.1.2 The DLI (Lüscher) Test The Intensity Difference LImen for loudness test (or Just Noticeable Difference, JND) is another recruitment test. A pure tone is amplitude modulated at a rate of 2/second. The patient has to determine whether this signal was steady or undulating (beating). To start the test select a modulation amplitude from 0.5 dB to 4.0 dB in the suprathreshold menu (as decribed before under 4.5.1) and press the STIM bar * or +. HL The LCD-display # shows DLI, 50 dB L 2000 Hz R 50 dB Air along with the chosen modu- Air Tone DLI 1.5 dB Tone lation amplitude (see picture 22). Now adjust the required test level with the level control knob Picture 22 MA 53 display with DLI test ( or ) and present the test signal by pressing the STIM bar * or +. To exit the test briefly press the PULSE button 4. 4.5.1.3 The SISI Test The SISI (Short Increment Sensitivity Index) is guided by the principle that patients with cochlear impairment are hypersensitive to small intensity increments. The continuous test tone is increased by 1 dB for a period of 0.2 seconds every 4.8 seconds. Whenever the patient hears the increment, he/she presses the patient response switch. The SISI test information and the test score are shown on the LCD-display #. The test will end automatically after 20 presented increments. The score is expressed as a percentage of ratio of the increments heard to the delivered increments (all increments heard = 100% - no increments heard = 0%). A high score indicates a cochlear impairment. A low score is related to normal hearing or conductive or retrocochlear pathology. 4.5.1.3.1 Preparation of the SISI Test To start the test select SISI in the suprathreshold menu (as decribed before under 4.5.1) and press the STIM bar * or +. The display # changes to the SISI conditioning screen (as shown in picture 23). Select the test frequency with HL dB L 2000 Hz R -10 Air dB 65 the frequency keys //! or Air Tone SISI Conditioning Tone 1/0. For the test you should choose the frequency where the 5 dB Presented: 0 Detected: 0 maximum bone conduction hearing loss is measured as Picture 23 MA 53 display with SISI conditioning 5 dB described in chapter 4.3. Geba53_e.03.b.wpd

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Operating Instructions MA 53

Adjust the test level with the level control knob ( or ). The level should be set to a value 20 dB above the individual hearing threshold (measured under chapter 4.1). It must reach at least 60 dBHL. Recognize that in the SISI mode the test signal is presented continuously. You can interrupt the test by pressing the STIM bar * or + for the time you hold it down. The patient must be instructed: "You will now hear a continuous tone. Every time it becomes louder, immediately push the switch”.

4.5.1.3.2 Training of the Patient Only with careful training during the following conditioning phase a valid test result can be achieved. HL The training starts with a dB L 2000 Hz R -10 dB 65 Air Air modulation level of 5 dB. That Tone SISI Conditioning Tone means a continuous tone, e.g. Tone now Answer now 65 dBHL, is briefly increased every dB Presented: 4 Detected: 2 5 4.8 seconds for 0.2 seconds by Picture 24 MA 53 display with 5 dB, e.g. to 70 dBHL. During the increment time the text “Tone SISI conditioning 5 dB and presented increment now” is shown on the lower area of the LCD display # (see picture 24). The text “Answer now” appears for approx. 1.5 seconds. During this period the patient may respond. If he/she answers too early or too late the answer will not be accepted by the MA 53. The number of detected increments is counted and shown on the lower right area of the display. Furthermore, the number of presented increments is shown (see picture 24). When you are sure that the patient has understood the object of the test, press the the PULSE button 4. The modulation level will be changed to 3 dB. If the patient has also understood this part of the test, press the PULSE button 4 again. The modulation level will be reduced to 2 dB. 4.5.1.3.3 SISI Test If the patient has understood the test up to here, press the PULSE button 4 again to start the SISI test. HL The LCD-display indicates SISI dB L 2000 Hz R -10 dB 65 Air Air Test (see picture 25) and the Tone SISI Test Tone modulation level is adjusted to 1 dB. Now 20 increments will 1 dB Presented: 0 Detected: 0 be presented to the patient. You can delay the test for the Picture 25 MA 53 display with SISI test Geba53_e.03.b.wpd

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Operating Instructions MA 53

time you press STIM bar * or +. This could be helpful in determining if the patient malingers. The test will end automatically HL 65 dB L 2000 Hz R -10 Air dB after 20 presented increments. Air SISI-Result Tone The number of detected Tone increments is counted and 20% Presented: 20 Detected: 4 indicated as percentage of the presented increments (see Picture 26 MA 53 display with SISI result picture 26). If you are sure that the result of HL R -10 Air dB 80 dB L 1500 Hz the test is consistent you can Air Tone SISI-Aborted Tone abort the test at any time by pressing the PULSE button 4. 50% Presented: 10 Detected: 5 The result is then indicated accordingly (picture 27). Retrocochlear hearing impair- Picture 27 MA 53 display with aborted SISI test ment is represented by low scores (< 25 %), cochlear defects by high scores (> 70 %). Press any button to leave the SISI test.

4.5.2 The Stenger Test The Stenger test is conducted as a malingering test in cases of alleged hearing loss or unilateral deafness. It is based on the premise that when two tones of the same frequency are presented simultaneously into both ears, only the louder tone will be perceived. The patient with a feigned hearing loss will not be able to hear the quiet tone, but will also not admit being able to hear the loud tone. Select the desired frequency with the frequency keys //! or 1/0 and adjust the sound intensities with the level control knobs ( and ). Present the tone with the STIM bars * and +. -

The easiest procedure is to present the desired frequency into to the better ear at a level of 10 dB above the threshold. At the same time present the signal into the poorer ear (the one with the possible feigned loss) at a level 10 dB below the admitted threshold. If there is a real loss in the poorer ear, the patient will be unaware of the signal in that ear and will respond only to the tone in the good ear. If the patient does not respond at all it is likely that the admitted threshold is incorrect and you have a “positive” Stenger.

4.5.2 The Threshold Decay (Carhart) Test This examination is conducted as a fatigue test in cases of sensitivity loss. Select the desired frequency with the frequency keys //! or 1/0. Geba53_e.03.b.wpd

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