natus Madsen A450 User manual

Madsen A450
User Guide
Doc. No.7-50-1830-EN/06
Part No.7-50-18300-EN

Copyright notice
© 2017,2021Natus MedicalDenmark ApS. All rights reserved. ® Natus, the NatusIcon, Aurical, Madsen, HI-PRO 2, Otoscan, ICS
and HORTMANN are registered trademarks of Natus MedicalDenmark ApS in the U.S.A. and/or other countries.
Version release date
2021-06-01 (221163)
Technical service and support
Please contact your supplier.
Madsen A450
2

Table of Contents
1 Device description 5
2 Intended use 5
3 Unpacking 6
4 Installation 6
5 Connecting accessories to Madsen A450 7
6 Powering the device 9
7 Connecting Madsen A450 to Otosuite 9
8 Control panels and on-screen controls 10
9 Toolbar icons in the Audiometry Module 15
10 PC keyboard controls 16
11 Proper transducer placement 16
12 Performing tone audiometry 17
13 Performing speech audiometry 18
14 Maintenance 20
15 Other references 22
16 Technical specifications 23
17 Definition of symbols 38
18 Warnings, Cautions, and Notes 44
19 Manufacturer 47
3
User Guide
Madsen A450

Madsen A450
4

1 Device description
Madsen A450 Madsen A450 is a PC-controlled audiometer for testing a person's
hearing.The audiometer is operated from the Otosuite Audiometry Module
PC software.
With Madsen A450 you can perform standard audiometric tests, tone and
speech audiometry and special tests.
2 Intended use
Madsen A450 with the Audiometry module
Users: audiologists, ENTs, hearing instrument dispensers and other health care professionals in testing the hearing of their
patients.
Use: diagnostic and clinical audiometric testing.
Intended Patient Population
The intended patient population is patients in all age groups, who are able to respond to the stimuli.
User Environment
• Professional healthcare facility environment
• The system is intended for use in a quiet environment within normal office temperature/humidity/pressure ranges
and lighting conditions
Clinical Benefit
Madsen A450 is used to conduct diagnostic and clinical audiometric testing, thereby providing a means to determine the
presence, type and degree of hearing loss, assist in the diagnosis of otologic disorders, and provide input for hearing aid
programming.
2.1 Typographical conventions
The use of Warning, Caution and Note
To draw your attention to information regarding safe and appropriate use of the device or software, the manual uses pre-
cautionary statements as follows:
Madsen A450 5
1 Device description

Warning •Indicates that there is a risk of death or serious injury to the user or patient.
Caution •Indicates that there is a risk of injury to the user or patient or risk of damage to data or the device.
Note •Indicates that you should take special notice.
To obtain a free printed copy of the user documentation, contact Natus MedicalDenmark ApS (www.natus.com).
3 Unpacking
1. Unpack the device carefully.
When you unpack the device and accessories, keep the packing material in which they were delivered. If you need to
send the device in for service, the original packing material will protect against damage during transport.
2. Visually inspect the equipment for possible damage.
If damage has occurred, do not put the device into operation. Contact your local distributor for assistance.
3. Check with the packing list to make sure that you have received all necessary parts and accessories. If your package is
incomplete, contact your local distributor.
4. Check the Calibration Certificate to make sure that the transducers (headphones and bone conductor) are the correct
ones, and that they comply with the ordered calibration standards.
4 Installation
Install Otosuite on the PC before you connect Madsen A450 to the PC.
For Otosuite installation instructions, see the OtosuiteInstallation Guide, on the Otosuite installation medium.
Madsen A450 is fully assembled on delivery, and you simply have to connect the cables.
Warning •To connect Madsen A450 to the PC, use the supplied USB cable. The cable length must not
exceed 3 m (approx. 10 feet).
Desktop or wall-mount installation
You can place Madsen A450 on the desktop or mount it on the wall.
6 Madsen A450
3 Unpacking

Wall-mount installation
It is recommended that you connect the external power sup-
ply and the accessories before you mount Madsen A450 on
the wall.
1. Select two suitably sized screws that will pass through the
wall-mount holes on the back of the device:
Max. screw diameter 4.3 mm (0.15 in).
Max. screw head diameter: 9 mm (0.35 in).
2. The distance between the two wall-mount holes on the
back of the device is 24 cm (9.4 inches), measured from
the center of each hole.
3. Mark up the two holes on the wall and make sure that the
device will be placed horizontally.
4. Fix the two screws in the wall.
5. Hang Madsen A450 on the screws.
Madsen A450 cabling
A. External power supply cable
B. USB cable between Madsen A450 and the PC
5 Connecting accessories to Madsen A450
The installation must be carried out in accordance with IEC 60601-1 (Ed. 3.1), UL60601-1, and CAN/CSAC22.2
No. 60601-1-14:2014.
It is a general rule for all electrical equipment used in the proximity of the client that:
• The connected equipment must comply with IEC 60601-1 (Ed. 3.1) except for the PC.
See also General warnings ►45.
For a detailed description of the connection panel, see the Madsen A450Reference Manual.
Connection panel - Madsen A450
Connect the plugs to the sockets in the connection panel.
Madsen A450 7
5 Connecting accessories to Madsen A450

1. PC/USB connection
2. External power supply
3. Sound field speakers (power output)
4. Insert Earphones
5. Headphones - air conduction
6. Patient Responder
7. Speaker, Analog (line output)
8. Operator monitor headset - headphones
9. Operator monitor headset - boom microphone
10. Insert Earphones
11. Headphones - air conduction
12. Bone conductor
13. Line-in
14. Counseling and Simulations headphones
15. Talk-back microphone
Note •Blue corresponds to Left and red corresponds to Right.
Warning •Use only the power supply provided by Natus.
Note •When you connect other electrical equipment to Madsen A450, remember that equipment that does not com-
ply with the same safety standards as Madsen A450 can lead to a general reduction in the system's safety level.
Connecting an external speaker
External speakers can be connected to Madsen A450 via powered output terminals or line-out terminals. In both cases you
should contact your service department for installation and calibration. See also Calibration ►22.
8 Madsen A450
5 Connecting accessories to Madsen A450

6 Powering the device
Madsen A450 is powered through an external power supply connected directly to the mains outlet.
Warning •Madsen A450 is not provided with a mains switch.
To connect Madsen A450 to the mains supply, plug the mains plug into the wall mains outlet.
To disconnect Madsen A450 from the mains supply, pull the mains plug out of the wall mains outlet. Do not position
the unit so that it is difficult to pull the mains plug out of the wall mains.
1. Plug the external power supply into the Power socket in the con-
nection panel.
2. Plug the mains plug of the external power supply into an AC mains
outlet with a three-wire protective ground.
Switching on Madsen A450
Warning •Use only the power supply provided by Natus.
3. Switch on the mains supply.
4. The On/Off indicator on Madsen A450 lights green.
Switching off Madsen A450
1. To completely switch off Madsen A450, disconnect the power supply from the mains outlet.
7 Connecting Madsen A450 to Otosuite
To connect Otometrics Madsen A450 to the PC, you must install Otosuite on the PC. For instructions, refer to the Install-
ation ►6section of this manual.
Caution •Use only the USB cable supplied with Madsen A450.
Madsen A450 9
6 Powering the device

1. Switch on the device.
2. Launch Otosuite.
3. Connect the USB cable from the USB socket on the back of the device to a USB socket on the PC. The
Otosuite software automatically detects the device.
8 Control panels and on-screen controls
Control panels
Tone testing Speech testing
In the control panel you can quickly select test ear, trans-
ducer, masking, and test type.
Click on the buttons to toggle the selection or right-click on a
button to select a combination of functions.
Your selections are shown in the Stimulus bar and as symbols
in the audiogram.
You can control the monitor level, activate the Talk Forward
dialog, and use the Test Selector to quick select the relevant
user test.
• Right-click on the buttons in the control panel to view
the right-click menu. Click to enable or disable selections
of your choice.
• Right-click on the blue masking link area in the control
panel to view the Masking Options right-click menu.
Click to enable or disable selections of your choice.
Tone testing
Test ear selection
•Right
•Both
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8 Control panels and on-screen controls

Test ear selection
•Left
Transducer selection
• Air conduction Phones (standard headphones)
• Air conduction Insert (earphones)
• Bone conduction Bone (bone conductor)
•SF Unaided (Sound Field speaker, unaided)
•SF Aided 1 and SF Aided 2 (Sound field speaker - Aided 1 and 2)
Stimulus type selection
•Tone
•Warble
•FRESH noise
•Pulsed
Test type selection
•AUD (audiogram threshold curve)
•SRT (Speech Recognition Threshold)
•WRS (Word Recognition Score)
•MCL (Most Comfortable Loudness level)
•UCL (Uncomfortable Loudness level)
Madsen A450 11
8 Control panels and on-screen controls

Speech testing
Test ear selection
•Right
•Both
•Left
Transducer selection
• Air conduction Phones (standard headphones)
• Air conduction Insert (earphones)
• Bone conduction Bone (bone conductor)
•SF Unaided (Sound Field speaker, unaided)
•SF Aided 1 and SF Aided 2 (Sound field speaker - Aided 1 and 2)
Stimulus type selection
• Microphone for presenting live speech stimulus
• Recorded stimulus
Talk Forward
Click to open the Talk Forward dialog. See the Madsen A450Reference Manual.
Enables communicating with the patient in the sound booth. This will display the Talk Forward dialog
box, where you can control the talk forward microphone sensitivity and the output level in dB HL to
the patient.
Monitor and Level
Click to open the Monitor and Level dialog. For more information, refer to the Madsen
A450Reference Manual.
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8 Control panels and on-screen controls

Test Selector
Click to open the Test Selector dialog. For more information, refer to the Madsen A450Reference
Manual.
The Control Panel right-click menu
Right-click on the buttons in the control panel to view the right-click menu. Click to enable or disable selections of your
choice.
Stimulus Ear Selec-
tion
Left,Right,Both
Transducer Selection Insert,Phones,Bone,SF Unaided,SF Aided 1,SF Aided 2
Stimulus Selection Tone
•Tone
•Warble
•FRESH
• Pulsedstimulus
•Stim. Lock
•Tracking
• 1 dB step
• 5 dB step
Speech
•Mic
•Recorded (Source A)
•Recorded (Source B)
•Int. CD (internal CD ROM built into the PC) (Speech)
•File (stored on hard drive) (Speech)
•Line In (external medium connected to the PC) (Speech)
•Stim. Lock (presents stimulus and masker simultaneously)
•Tracking (increases stimulus and masker intensity by the same number of dB)
•1 dB Step
•5 dB Step
Madsen A450 13
8 Control panels and on-screen controls

Curve Selection •AUD (audiogram threshold curve) (Tone)
•MCL
•UCL
•SDT (Speech Detection Threshold) (Speech)
•SRT (Speech Recognition Threshold) (Speech)
•WRS (Word Recognition Score) (Speech)
•SNR (Signal to Noise Ratio) (Speech)
Masking Transducer
Selection
•Insert
•Phone
•Bone (Speech)
•SF
Masking Options •Contralateral
•Ipsilateral
•NBN (Tone)
•WN (Tone)
•Stimulus 2 (Stenger)
•SWN (Speech)
•Mic (Speech)
•Recorded (Source A) (Speech)
•Recorded (Source B) (Speech)
The stimulus bar
Test controls provide a means of operating the audiometer if you use the mouse and on-screen options to perform tests.
• To enable test controls, select Tools> Options> Audiometry> General> On-screen controls> Show> On.
Button Description
Present Click to present the stimulus.
Store Click to store the data point or row.
Mask Click to enable or disable masking.
Silence Mode
Silence Mode allows you to control tone levels and presentation by hovering the mouse cursor over the respective on-
screen controls. This is particularly useful when the operator of the audiometer and the person being tested are in the
same room.
• To enable silence mode, select Tools> Options> Audiometry> General> On-screen controls> Silence Mode> On.
• To change the level and frequency by more than one click at a time, use the mouse scroll wheel.
14 Madsen A450
8 Control panels and on-screen controls

9 Toolbar icons in the Audiometry Module
The icons available in the toolbar depend on the test function that you have selected.
Functions not available in the toolbar can be accessed from the View menu or from Tools> Options dialog.
Audiometry icons
Tone audiometry Speech audiometry
Toolbar selections
Menu item Icon Description
View> Combined
Audiogram
Click to toggle between viewing both ears in a single audiogram (com-
bined audiogram) or both a left and a right audiogram on your screen.
Combined View
• Click to view both ears in a single audiogram.
Split View
• Click to view separate audiograms for each ear.
Scoring and Playing Click to open the Scoring and Playing dialog.
Menu selections
Menu item Icon Description
View> Select Ori-
entation
Click to select the perspective of the patient's ears as presented on
the screen for graph and table views.
You can also select the location of the stimulus control.
View> Manual entry Click to create an audiogram manually.
Madsen A450 15
9 Toolbar icons in the Audiometry Module

10 PC keyboard controls
You can open a separate PDF-file to have a proper view of the keyboard short-
cuts.
After you install Otosuite, you can find Otosuite manuals and related doc-
umentation on your PC. In the Start menu, open OtosuiteManuals, which
contains an overview with links to all manuals.
Note •The actual position of the keys may depend on your keyboard
type.
11 Proper transducer placement
Headphones
1. Loosen the headband and place both the left and right side of the headphones simultaneously.
Note •If the headphones are not placed properly, there is risk of causing the ear canal to collapse which will result in
elevated thresholds.
2. Aim the center of the headphones towards the patient's ear canals and gently place them against the ears.
3. Tighten the headband while holding the headphones in place with your thumbs.
4. Examine the placement of the headphones to make sure they are level, and properly positioned.
Insert Earphones
1. Select the largest foam eartip that will fit into the patient's ear.
If the eartip is too small the sound will leak out and the sound level will not be accurate at the eardrum.
Insert earphones have greater attenuation between ears especially at the low frequencies; this reduces the need for
masking.
2. It is best to clip the insert earphone transducers behind the child or on the back of their clothing and then fit the
foam eartip into the child's ears.
Bone Conductor
Note •For unmasked bone thresholds, you can store binaural data:
- Select Both in the Ear Selection part of the control panel.
If there is a difference of 10dB or greater between the bone conduction threshold and the air conduction threshold of
16 Madsen A450
10 PC keyboard controls

the same ear, masking is needed. The Masking Assistant can assist you in determining which thresholds need to be
masked.
If the SRT of the test ear and the bone conduction PTA of the nontest ear differ by 45 dB or more, masking is needed.
Mastoid placement
1. Move any hair covering the mastoid out of the way and place the flat round part of the bone conductor securely on
the boniest portion of the mastoid without any part of the transducer touching the external ear.
2. Make sure the bone conductor is tight on the mastoid but still comfortable.
3. If you are going to perform masking with earphones, position the other end of the bone conductor headband over the
patient's temple on the opposite side of the head so that the headband of the earphones and bone conductor fit on
the patient's head.
Loudspeaker placement
The environment in which sound-field audiometry is performed may affect the sound field near the patient.
The performance of loudspeakers for Madsen A450 was tested by Natus under free-field conditions in a large anechoic
chamber. Sound pressure level, frequency response and distortion were measured by a microphone placed 1 m from the
front of the speaker.
When speakers are installed in other types of environment, the characteristics of the resulting sound field should be eval-
uated by qualified personnel.
12 Performing tone audiometry
A. Menu bar
B. Audiometry toolbar
C. Stimulus bar
D. Control panel
E. Work area
F. Feature boxes
Whenever the test buttons and other functions are used, you can use the corresponding keys on the keyboard, or the on-
screen controls located at the top of the screen or in the Control Panel to the left.
For detailed examples of audiometric testing, see the Madsen A450 Reference Manual.
1. Select the Tone screen in the Otosuite Audiometry module.
Madsen A450 17
12 Performing tone audiometry

2. Prepare the patient. If you wish to instruct the patient after you have placed the transducers on the head of the
patient, you can use the Talk Forward button. You can talk to the patient to adjust the patient communication levels
when Talk Forward is active.
3. In the Control Panel, select test conditions for ear, transducer, unmasked/masked, and test type.
4. Select the test frequency with the Right/Left arrow buttons (or on keypad).
5. Select the stimulus level with the Up/Down arrow buttons (or on keypad).
6. Present the tone stimulus with the Present button or the space bar on the keypad.
7. Use the Store button (the S key on the keypad) to store the data point and proceed to the next frequency.
8. Repeat steps 4 to 7 until all the measurements you need have been completed. If needed, did you test:
– Both ears
– Air conduction
– Bone conduction
– Masking (Mask button or M on the keypad)
– Audiogram threshold (AUD), MCL and UCL
9. Save the audiogram.
Note •White noise can be selected for masking of pure tones. The white noise signal is calibrated for pure tone effect-
ive masking, i.e. the white noise sound pressure level varies with the pure tone frequency. If you wish to obtain a cer-
tain white noise level measured in dB SPL, you should use Conversion Table 2 to determine the appropriate
attenuator setting. See Technical specifications ►23.
13 Performing speech audiometry
A. Menu bar
B. Audiometry toolbar
C. Stimulus and scoring bar
D. Control panel
E. Work area
F. Feature boxes
G. Audiogram
Whenever the test buttons and other functions are used, you can use the corresponding keys on the keyboard, or the on-
screen controls located at the top of the screen or in the Control Panel to the left.
18 Madsen A450
13 Performing speech audiometry

For detailed examples of audiometric testing, see the Madsen A450 Reference Manual.
1. Select the Speech screen in the Otosuite Audiometry module.
2. If needed, click the Scoring and Playing icon to set up word or phoneme scoring.
3. Prepare the patient. If you wish to instruct the patient after you have placed the transducers on the head of the
patient, you can use the Talk Forward button. You can talk to the patient to adjust the patient communication levels
when Talk Forward is active.
4. In the Control Panel, select test conditions for ear, transducer, unmasked/masked, and test type.
5. Select the stimulus level with the Up/Down arrow buttons (or on keypad).
6. Select speech input signals.
You can choose from either microphone input or recorded input source. Combining recorded Source A and Source B
as Input sources in the Test Options section of the Control Panel will replace the audiometer speech masking with a
recorded input.
7. Select your speech input from the right-click menu in the control panel.
–Int. CD (CD material in CD/DVD drive)
–File (integrated Otosuite Speech Material or regular sound files)
–Line In (analog input from external sound players, e.g. CD, MD, MP3 or cassette recorders connected to the audi-
ometer via the Line In input).'
Note •If an external playback device is used to generate speech stimuli via the line input, care must be taken to
ensure that the player has a flat frequency response in the range 125 Hz to 6300 Hz. The maximum allowable
deviation from the average response level is +/-1 dB; the average response level should be measured over the
range 250 Hz to 4000 Hz.
The headset microphone is ready for use and does not require calibration or equalization procedures. The headset
microphone should be turned to a position just below the operator’s mouth.
If an external playback device is used to generate speech stimuli via the line input of Madsen A450, only a high
quality CD player or similar device should be used; tape recordings may not provide a sufficient signal to noise
ratio. Preferably, the external device should deliver its output via a fixed-level line out connector. The input gain
on Madsen A450 should be adjusted to obtain a 0 dBVU reading when the calibration signal is played by the
external device.
8. You can find speech material files in the File/track/list selection drop-down list.
Madsen A450 19
13 Performing speech audiometry

Note •You should only use speech materials with a stated relationship between the level of the speech signal and
the calibration signal.
Speech materials delivered on CD or other media are normally accompanied by a description of this relationship.
You should follow the instructions supplied with the speech materials, using the VU-meter in Otosuite for adjust-
ment of input gain
If you are using built-in speech materials supplied with Otosuite, the speech levels have been adjusted according
to the original speech material instructions.
Note •Speech signals are calibrated in dB HL.
If you are using an integrated word list, the word list is shown on the screen.
9. Present the word lists with the Play button.
10. Use the Correct (+) and Incorrect (-) buttons or click directly on the key word to score.
11. Store the current data as the result, either by clicking Store in the highlighted field, or
by pressing (S) on the keyboard.
12. Repeat until all the measurements you need have been completed.
Dosimeter
A dosimeter is built into Madsen A450. If you are using live speech, it will be working in the background as a safety pre-
caution. The system monitors the sound level versus duration of exposure(1).
If the patient is exposed to excessive levels of noise during the session, the system will interrupt the signal and display a
warning.
(1)Noise Exposure: Explanation of OSHA and NIOSH Safe.Exposure Limits and the Importance of Noise Dosimetry by Patricia
A. Niquette, AuD, Etymotic Research Inc.
14 Maintenance
Madsen A450 requires regular maintenance to continue operating as designed. This includes visual inspection, cleaning,
and calibration. If the equipment shows signs of damage or material degradation, do not use the device and contact your
supplier.
20 Madsen A450
14 Maintenance