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0611 

Verifit User’s Guide Version 2.8  

Page 41 

8.4 

ANSI 1996 Linear and AGC tests 

FastFacts 8.4: ANSI 1996 Linear and AGC tests 

1) 

Press <Tests>, then highlight and <PICK> [Linear] or [AGC]. 

2) 

Highlight and <PICK> [Start test]; test setup instructions will be displayed. 

3) 

Refer to 

7.11: Coupling the hearing instrument

, 

7.12: Positioning the hearing 

instrument

 and 

2.6: Battery pill use and care

 to prepare the instrument for 

testing. 

4)  Turn the instrument ON

. 

5) 

Set the gain control (manual or programmable) to maximum with all other 
controls set to provide the widest frequency response, greatest gain and 
highest maximum output. AGC controls and/or programmable parameters 
should be set as designated by the manufacturer. 

6) 

Press <Continue> to run the test or press <Cancel> to abort the test. Note 
that, if required, the Verifit will pause during the test to request that the volume 
control be adjusted to the Reference Test Position (RTP). Open the HIT 
chamber if necessary and, without moving the hearing instrument, adjust the 
user gain control until the large vertical arrow on the screen prompt 
disappears. Press <Continue> to resume the test.

 

If you are unsure which test sequence to run, try [AGC] first. If attack and release 
times are all near zero, the instrument is probably linear. 

Содержание Verifit VF-1

Страница 1: ...VERIFIT VF 1 REAL EAR HEARING AID ANALYZER USER S GUIDE Version 2 8 November 2006 Verifit VF 1...

Страница 2: ...15 2 8 External display printer speaker 16 3 General Operation 16 3 1 Section overview 16 3 2 Input device operation 17 3 3 Barcode data input 18 3 4 Keypad keys 19 3 5 Menus lists and buttons 20 3 6...

Страница 3: ...t 38 7 12 Positioning the hearing instrument 39 8 ANSI S3 22 Hearing Aid Tests 39 8 1 Section overview 39 8 2 ANSI S3 22 1996 facts 40 8 3 ANSI S3 22 2003 facts 40 8 4 ANSI 1996 Linear and AGC tests 4...

Страница 4: ...REM curves 64 12 Real Ear Directional Test 65 12 1 Section overview 65 12 2 REM directional testing 66 13 REM Manual Control 67 13 1 Section overview 67 13 2 Manual control measurements 67 13 3 Sound...

Страница 5: ...to targets for soft speech 92 19 6 Fitting to targets for loud sounds 93 19 7 Fitting to targets for mid level speech 94 19 8 Open fittings in Speechmap 94 19 9 FM fitting and verification 95 19 10 CR...

Страница 6: ...User s Guide Version 2 8 Page 6 21 12 Barcode scanner malfunction 105 22 Technical Specifications 106 23 Glossary 107 24 References 111 25 Appendix 1 AudioNote 2 1 VERIFIT and RM500SL Test Signals and...

Страница 7: ...p 2 Getting Started 12 Real Ear Directional Test 3 General Operation 13 REM Manual Control 4 General Setup 14 Sensory loss simulator 5 Networking 15 Occlusion Effect Test 6 Printing and Storing Result...

Страница 8: ...O tone bursts have been lengthened to 128ms for better correlation with loudness perception 11 Input Output screens now have a cursor readout Left click on any graph 12 New calibration equalization si...

Страница 9: ...of Etymotic Research Inc KEMAR is a registered trademark of Knowles Electronics Inc QUEST is a trademark of Quest Technologies Inc PostScript is a registered trademark of Adobe Systems Inc Acknowledge...

Страница 10: ...tic emissions The Verifit is intended for use in the electromagnetic environment specified below The user of the Verifit should assure that it is used in such an environment Emissions test Compliance...

Страница 11: ...printer speaker 1 Carefully unpack the two parts of the Verifit and check the contents of the shipping box against the enclosed packing list Note that some parts may be packed inside the test chamber...

Страница 12: ...low the external speaker jacks The door of the CD drive will open only when power is first applied If necessary to open the CD drive without power insert the end of a small screwdriver or a paper clip...

Страница 13: ...ler microphone into the connectors in the test chamber as shown 2 Plug the probe microphone assemblies into the probe connectors located at the front edge of the built in keypad as shown NOTE A microp...

Страница 14: ...e BTE HA 2 coupler is free from any cracks tears 5 DO make sure that any replacement 13 tubing used on the BTE coupler is 38 inches in length Probe microphones Debris can alter the probe module refere...

Страница 15: ...upplied by Audioscan may not work and are not supported by Audioscan In the European Community if this device is connected to one or more other devices to make a system the CE mark on this device is o...

Страница 16: ...ically display what is on the internal screen The monitor should be capable of 800 x 600 resolution An external printer may be connected to the parallel printer connector or to one of the USB ports It...

Страница 17: ...d Y co ordinates Clicking again will dismiss the cursor Function Keypad QWERTY Mouse Summon Help menu Help F1 Right click Summon Setup menu Setup F2 Right click Summon Test menu Tests F3 Right click S...

Страница 18: ...r and it does not matter if the barcode is upside down 1 Select Speechmap or Insertion gain from the Tests menu 2 Hold the printout so that the barcode to be scanned is flat With the scanner 6 8 from...

Страница 19: ...u containing a list of the available test procedures Session Summon Session Data Menu to erase or export data Left Right Used in the Single View Mode to alternate between ears or A B Data Used in the...

Страница 20: ...r by clicking the left mouse button This process also selects the highlighted item in a list box There are three different types of screen buttons When selected a Menu Button displays a menu a setup b...

Страница 21: ...M carefully snap it label up onto the spindle 6 Gently push the CD drive door inward until it snaps into place 7 Press Continue and follow any on screen instructions 8 Press Continue to exit Setup Sof...

Страница 22: ...The screen saver blanks the screen after 60 90 or 120 minutes of inactivity to prolong the life of the display The settings apply to both the internal display and to any connected external monitor To...

Страница 23: ...that the IP address of the remote computer is on the same subnet as the Verifit These settings should be obtained from your network administrator The Verifit may be connected to a Windows network by c...

Страница 24: ...Test connection The Verifit will prompt you for an IP address of a computer or router on your network In a single PC to Verifit network this is the IP address of the PC you are connecting to The comp...

Страница 25: ...ed audiometric data and fixed or variable headers and comments via a connected keyboard may be added to printouts but not when saving to a file Session data may also be saved as a delimited text file...

Страница 26: ...per feeding from the top of roll 5 Insert the paper s leading edge into the lower slot at rear of tray 6 Feed the paper by highlighting the on screen Paper Feed button and pressing PICK 7 Advance the...

Страница 27: ...y also be added 1 Connect a computer keyboard to the rear connector panel 2 Press Setup then highlight and PICK Printing 3 Highlight Page setup and press PICK to display the page setup poster 4 To pri...

Страница 28: ...t After about 4 seconds a message will advise that data is being saved Do not unplug the USB stick until this message disappears 6 To input a file name from a connected keyboard each time you print hi...

Страница 29: ...n to allow Anonymous Logon to print to the shared printer 1 Press Setup then highlight and PICK Printing 2 Highlight PICK Other network printer or Windows shared printer 3 Highlight PICK Printer detai...

Страница 30: ...most spreadsheet programs After pasting to Excel select Text to Columns in the Data menu and indicate that the data are space delimited need not repeat if file remains open To save the screen image as...

Страница 31: ...unning Windows 2000 or Windows XP Pro and the NOAH 3 framework and having a 9 pin RS232 serial COM port The Verifit must be running software 2 2 or higher Connecting to the PC Connect the 9 pin RS232...

Страница 32: ...pted to Add which adds a new session or Cancel which exits without saving To send data either Verifit or public data from other modules to the Verifit click Send Data on the menu bar The data sent dep...

Страница 33: ...n a screen button in the inactive test panel However this also operates the button The appearance of Hearing Instrument Test HIT screens may be changed in several ways Most screens may be viewed as a...

Страница 34: ...curve does not erase it To hide or show test curve s 1 Highlight then PICK Curve Hide Show 2 Highlight then PICK the desired test curve to toggle between Hide or Show The curve will toggle on or off...

Страница 35: ...To change the frequencies for attack and release time measurements In the list of available frequencies highlight and PICK the frequencies to be used to measure attack and release time Press Continue...

Страница 36: ...ening the latch at the front of the lid 3 Press Tests then highlight and PICK Calibrate from the Hearing Instruments Test column 4 Highlight then PICK Daily or Weekly to select the calibration interva...

Страница 37: ...ing into the calibrator opening 4 Turn the calibrator on and adjust it to present one of the available frequencies and levels e g 94 dB SPL at 1000 Hz 5 Press Tests then highlight and PICK HIT Manual...

Страница 38: ...o the metal stem of the HA 2 coupler The 13 tubing should be inspected regularly for cracks which will cause feedback Custom instruments are sealed to the HA 1 coupler with putty so that the end of th...

Страница 39: ...NSI input output curves 8 3 ANSI S3 22 2003 facts 8 8 ANSI telecoil terminology 8 4 ANSI 1996 Linear and AGC tests 8 9 ANSI telephone simulator TMFS test 8 5 ANSI 2003 Linear and AGC tests 8 10 ANSI t...

Страница 40: ...90 dB input SPL the HFA or SPA and peak value of this curve the frequency of the peak and the HFA or SPA gain for a 50 dB input SPL With the gain control at RTP these sequences also provide a frequen...

Страница 41: ...o provide the widest frequency response greatest gain and highest maximum output AGC controls and or programmable parameters should be set as designated by the manufacturer 6 Press Continue to run the...

Страница 42: ...test Note that if required the Verifit will pause during the test to request that the gain control be adjusted to the Reference Test Setting RTS If necessary open the HIT chamber and without moving th...

Страница 43: ...L average gain at RTP k is usually but not always measured at 60 dB SPL and the frequency response l is run at 60 dB SPL for linear aids or at 50 dB SPL for AGC aids In 2003 tests Full on average gain...

Страница 44: ...s Tests then highlight and PICK Input Output 2 Refer to 7 11 Coupling the hearing instrument 7 12 Positioning the hearing instrument and 2 6 Battery pill use and care to prepare the instrument for tes...

Страница 45: ...inductive telephone simulator SPL developed in a 2cc coupler by a hearing instrument with the gain control in the RTP 1996 or RTS 2003 when the input is the magnetic field generated by a TMFS HFA or S...

Страница 46: ...3 Set the aid to T telecoil input 4 Highlight and PICK Start TMFS test Test setup instructions are displayed 5 Position the aid on the T inscribed on the test chamber floor BTE aids should lie as fla...

Страница 47: ...this test See 8 4 ANSI 1996 Linear and AGC tests 8 5 ANSI 2003 Linear and AGC tests 1 First complete an ANSI Linear or AGC test 2 Press Tests 3 Highlight and PICK Telecoil 4 Set the aid to T telecoil...

Страница 48: ...0 dB in 5 dB steps Can be used as a dual channel sound level meter with 1 12th octave A and C filters This section covers the following topics 9 2 Harmonic distortion 9 8 Multicurve results 9 3 Direct...

Страница 49: ...hone The coupler SPL is then analysed into two real time response curves labeled L left and R right to indicate which speaker generated the curve Since the curves are generated simultaneously their di...

Страница 50: ...shown so that the direction of maximum sensitivity is toward one of the speakers and a line joining the microphone ports is at 45 and horizontal Locate the HIT reference microphone at the front micro...

Страница 51: ...floor of the test chamber The directional BTE instrument should be positioned so that a line joining the microphone openings on the instrument is at 45 as shown Position the HIT reference microphone a...

Страница 52: ...al function in the test chamber 1 Mount the hearing aid to the appropriate coupler see 7 11 Coupling the hearing instrument 2 Position the hearing instrument in the test chamber as shown in 9 4 Direct...

Страница 53: ...ue captures the displayed spectrum If the stimulus type is Swept a swept filter analysis is performed in 1 12th octave bands and displayed at 1 3rd octave frequencies Pressing Continue causes the swep...

Страница 54: ...he input signal is 90 dB SPL at the HFA or SPA frequencies Avg 90 dB Battery life is estimated assuming 80 quiescent and 20 Avg 90 dB use With the hearing instrument set as normally used 1 Install and...

Страница 55: ...uency without stopping the test When set for a stimulus level of 0 dB off the Manual control mode allows the Verifit to be used as a sound level meter Sound at the HIT reference microphone and the cou...

Страница 56: ...r band SPL in the ear canal for a given stimulus with a working hearing aid in place Real Ear Aided Gain REAG Difference in dB between the REAR and the stimulus SPL or stimulus band SPL Real Ear Satur...

Страница 57: ...this purpose The speaker should be mounted at ear height well away from reflective surfaces See 10 8 Positioning the client To select this speaker 1 Press Setup then highlight and PICK Speakers 2 Hig...

Страница 58: ...ration with time the module may need replacement See 10 5 Calibration check for probe module Switching left and right probe modules after calibration will result in the wrong calibration curve being a...

Страница 59: ...may be checked against a high quality sound level meter 1 Press Tests then highlight and PICK REM Manual control 2 Highlight PICK Level then highlight PICK 70 from the drop down list 3 Highlight and P...

Страница 60: ...he behavioral pure tone threshold that accounts for a measured ABR threshold Normalized Hearing Level nHL a Stimulus peak to peak equivalent SPL pe SPL at ABR threshold relative to the average stimulu...

Страница 61: ...here is no ear canal obstruction e g cerumen and to get a sense of ear canal length 2 Install a new probe tube on the probe module Set the black marker ring approximately 28 mm from end of probe tube...

Страница 62: ...change the presentation highlight then PICK Single view or Dual view To switch between left and right test panel in single view press Left Right To switch between left and right test panel in dual vi...

Страница 63: ...ng instrument The gain values given assume the hearing instrument is linear for a 70 dB speech input This assumption is necessary to allow the microphone location effects to be incorporated For BTE an...

Страница 64: ...han one curve you may show or hide test curves Hiding a curve does not erase it To erase curves use the Session key To hide or show test curve s 1 Highlight then PICK Curve Hide Show 2 Highlight then...

Страница 65: ...real time response curves labeled F front and B back to indicate which speaker generated the curve Since the curves are generated simultaneously their difference is not influenced by electronic proces...

Страница 66: ...e REAR column Test signals are presented from both speakers and two real time curves appear on the screen The heavier one is the response to the front speaker signal and the lighter one the response t...

Страница 67: ...oth channels This section covers the following topics 13 2 Manual control measurements 13 3 Sound level meter using REM probe 1 Refer to 10 Real Ear Measurement Setup to prepare the system for use and...

Страница 68: ...e system for use and for proper positioning of the client and the probe tube 2 Press Tests then highlight PICK Manual control in the REM column 3 Highlight and PICK the Level window then highlight and...

Страница 69: ...This SLS does not simulate broadening of the auditory filters or other distortions that may accompany cochlear hearing loss For comparison purposes a simulation of a purely conductive loss is also pr...

Страница 70: ...lubricant applied to the earmold or custom instrument shell in the vicinity of the probe tube will make insertion easier and prevent slit leaks around the tube 3 Turn the hearing aid OFF 4 Press Tests...

Страница 71: ...argets you should use measured or age related RECD Insert phone audiometry with measured RECD and REM verification provides the best fitting accuracy with S REM verification being slightly less accura...

Страница 72: ...3 If no coupler response exists or the measurement interval has been exceeded connect the RECD transducer to the BTE coupler 4 Highlight and PICK Measure coupler and follow the setup instructions 5 P...

Страница 73: ...to advance the probe tube further into the ear canal Insertion depth should be as used with insert phones Allow the foam tip to fully expand in the ear 7 Press Continue to generate the real ear respo...

Страница 74: ...real ear pink and in the 2cc coupler green The difference between these curves is the RECD cyan An age appropriate average RECD is shown for reference dotted The RECD for the right ear shows a negati...

Страница 75: ...Measurement Setup and 11 REM Screen Setup for terminology and information on preparing the system for use and for proper positioning of the client and the probe tube This section covers the following...

Страница 76: ...from BTE ITE ITC CIC Body This changes the CORFIG used for 2cc targets 3 Highlight and PICK fitting method to chose from FIG6 NAL NL1 NAL R POGO II BERGER LIBBY USER NONE An estimated aided threshold...

Страница 77: ...and parameters manually 1 Highlight and PICK Audiometry 2 Highlight and PICK Transducer then highlight and PICK from the list 3 Highlight and PICK REUR then highlight and PICK to toggle selection Meas...

Страница 78: ...me see 17 4 Audiometric data entry or press Continue to proceed with the measurement 4 Highlight and PICK REUR below REAR REIG test 3 5 Press Continue to accept the default 55 dB SPL Pink noise stimul...

Страница 79: ...ise when using the NAL NL1 fitting formula Use Swept when testing maximum output capabilities 7 Highlight and PICK Level then highlight and PICK a stimulus level from the list box Use the level shown...

Страница 80: ...lying by 100 Level distortion effects are included but no hearing loss desensitization is applied An idealized speech region of LTASS 15 dB is used The speech recognition associated with a given SII i...

Страница 81: ...ect REAR 1 and record a response using Pink noise at 55 It should be like a normal REUR If not the ear may not be fully open 4 Position the speaker at 45 to the poor ear 5 Set Instrument to CROS 6 Sel...

Страница 82: ...important for non linear hearing aids analog or digital because their processing is signal dependent It also makes provision to correct audiometric data and 2cc coupler measurements for age related or...

Страница 83: ...rsion of DSL 5 0 may differ from others in the following ways 1 DSL 5 0 uses RECD values for ages 119 months from a different source than for ages 119 months Audioscan has used the RECD values for a 1...

Страница 84: ...spectrum has been removed and an own voice spectrum has been added As a result of a re analysis of published data the vocal effort effects for Soft and Average speech levels have been made the same In...

Страница 85: ...II calculation When using live speech a Freeze curve button captures short term speech features See 18 10 SII calculation in Speechmap and 20 Speechmap Technical Details Before starting please review...

Страница 86: ...0611 Verifit User s Guide Version 2 8 Page 86 18 7 Screen tour unaided screen FastFacts 18 7 Screen tour unaided screen 18 8 Screen tour aided screen FastFacts 18 8 Screen tour aided screen...

Страница 87: ...ion the stimulus delivered to the hearing instrument microphone is modified to include average microphone location effects for the hearing instrument type indicated The screen display for both modes i...

Страница 88: ...Level distortion effects are included but no hearing loss desensitization is applied An idealized speech region of LTASS 15 dB is used The speech recognition associated with a given SII is a function...

Страница 89: ...sment data choices 1 and 19 4 Assessment data choices 2 3 Press Continue to proceed to data entry 4 Enter HL threshold using a mouse keypad or keyboard Left click the mouse on the audiogram to enter a...

Страница 90: ...from Headphone Insert Foam Insert Mold Soundfield ABR eHL ABR nHL If Insert Foam or Mold is selected the appropriate RECD will be used to convert entered HL values to SPL values If Soundfield is sele...

Страница 91: ...values may be entered and are required at all 9 audiometric frequencies 7 Binaural Select from Yes No Determines if fitting targets will be adjusted for binaural summation effects 8 REDD Real ear to D...

Страница 92: ...data entry 1 Select Audiometry to choose the target method and enter audiometric data 2 Select REAR 1 and set stimulus to Speech std 1 or Speech std 2 and level to 50 Elongated symbols show the target...

Страница 93: ...ust high level gain and or output limiting e g MPO PC so the curve matches the REAR90 targets DSL or approaches but doesn t exceed the RESR targets NAL NL1 at all frequencies Press Continue to record...

Страница 94: ...real ear SPL targets for open fittings it doesn t matter how the sound reaches the TM the perception is the same However the sound that escapes from a vent or open fitting may be detected by the REM r...

Страница 95: ...ts see note Avoid controls that change FM gain 3 Switch to FM only operation If you are in S REM mode move the coupler and hearing aid or earpiece outside the test chamber In either REM or S REM mode...

Страница 96: ...e using Pink noise at Soft 55 It should be like a normal REUR If not the ear may not be fully open 4 Position the speaker at 45 to the poor ear 5 Set Instrument to CROS 6 Select REAR 2 and obtain a re...

Страница 97: ...An own voice filter is also available at the 75 dB SPL level This is intended to produce a spectrum and level at a BTE microphone location similar to that produced by the voice of an average wearer A...

Страница 98: ...5 52 8 53 14 4 10 8 26 4 32 1 1000 51 0 52 0 52 7 50 4 53 15 0 10 5 26 4 32 7 1250 50 5 51 0 45 4 51 3 53 14 8 5 5 22 0 33 6 1600 48 0 51 1 41 1 48 5 53 15 5 4 0 22 1 33 9 2000 45 0 51 2 39 7 47 0 53...

Страница 99: ...5 0 5 0 3 0 8 3 0 315 0 8 0 8 0 3 0 7 3 0 400 1 1 1 0 0 7 0 5 3 0 500 1 2 1 8 0 0 0 4 4 0 630 1 1 2 0 0 1 0 4 3 0 800 0 9 2 0 0 4 0 4 2 0 1000 0 3 1 5 1 2 0 6 0 0 1250 0 6 0 3 1 6 1 1 0 0 1600 2 5 0...

Страница 100: ...ed L1 the 1st or 99th percentile has historically been referred to as the speech peak for that band The curve for these 1 levels is approximately 12 dB above the LTASS The level in each band that is e...

Страница 101: ...reconnect the microphones one by one running self test each time until a failure occurs If the failure returns display and print the test results and contact Audioscan for help This section covers com...

Страница 102: ...may be coupled into the test chamber from other equipment on the same table or wooden floor Computers fans and air conditioners may be the source of the vibration Try turning off suspected sources to...

Страница 103: ...a hearing instrument test It indicates that the Verifit is not measuring any sound at the HIT reference microphone The HIT reference microphone is the white microphone located in the test chamber v En...

Страница 104: ...tly different from what is expected It may be accompanied by a REM reference microphone error v Check that a probe microphone assembly is securely plugged into the PROBE socket of the side Right or Le...

Страница 105: ...rom walls and hard objects Move the client closer to the speaker s v The speaker or connecting cable external speakers only is defective If this is the case you should not hear any sound coming from t...

Страница 106: ...000 Hz 2 5 dB 5000 8000 Hz Measurement range 30 140 dB SPL Harmonic distortion measurement 2nd 3rd or 2 nd plus 3rd Harmonic distortion range 200 to 4000 Hz Harmonic distortion accuracy 1 Battery drai...

Страница 107: ...onse for Flat Insertion Gain the transformation added to real ear insertion gain to obtain 2 cc coupler gain Assumes linear amplification Coupler a device used to acoustically couple an earphone or he...

Страница 108: ...GC in which the signal level is regulated before the volume control Input Output function steady state single frequency plot of the coupler SPL on the ordinate as a function of input SPL on the abscis...

Страница 109: ...r BSPL at the field reference point for a specified sound field with the hearing aid in place and turned on ANSI S3 46 REAR Real Ear Aided Response the SPL or BSPL as a function of frequency at a spec...

Страница 110: ...2 3 of an octave ANSI S3 22 See also HFA Spectrum the BSPL as a function of frequency for a broad band signal SII Speech Intelligibility Index a quantity calculated from measures of speech noise and...

Страница 111: ...n Amplification 9 4 199 226 Bentler R A Pavlovic C V 1989 Transfer functions and correction factors used in hearing aid evaluation and research Ear and Hearing 10 10 58 63 Byrne D 1977 The speech spec...

Страница 112: ...differences in children with grommets British Journal of Audiology 31 63 69 Moodie K S 1996 A practical approach to hearing aid selection BSA News 18 6 8 Moodie K S Seewald R C Sinclair S T 1994 Proc...

Страница 113: ...wald R Moodie S T Scollie S Bagatto M 2005 The DSL method for pediatric hearing instrument fitting Historical perspective and current issues Trends in Amplification 9 4 145 157 Seewald R C Moodie K S...

Страница 114: ...SL Test Signals and Analysis For additional details of the signals and their analysis see the appended AudioNote Within the European Community EU Authorised representative PC Werth Ltd Audiology House...

Страница 115: ...telephone magnetic field simulator TMFS the test chamber magnetic field test loop Verifit only or the sound field loudspeaker s Device output signals are measured in the 2 cm 3 coupler via the couple...

Страница 116: ...E re overall SPL 18 00 17 00 16 00 15 00 14 00 13 00 12 00 11 00 10 00 9 00 8 00 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 6300 8000 BAND CENTER FREQUENCY Hz BAND SPL dB re o...

Страница 117: ...m A Loud vocal effort filter is applied to the 75 dB level signals This is shown in Figure 2 The ICRA distorted speech signal is a recording of an English speaking talker that has been digitally modif...

Страница 118: ...stimating the audibility or comfort or discomfort of a complex signal It should be noted that in all Real Ear Measurements 1 3 octave band SPL is displayed and reported when saving data to a file at 1...

Страница 119: ...d or UCL will actually be well above it Figure 5 Output left and Gain right curves for a linear hearing aid generated using a swept tone 1 and pink noise analyzed in 1 12 octave bands 2 Dual view not...

Страница 120: ...ls is approximately 12 dB above the LTASS The level in each band that is exceeded by 70 of the samples called L70 the 70th or 30th percentile has historically been called the valley of speech for that...

Страница 121: ...se conflicting needs speech signals are first presented in a repeating loop with a sound field equalization test prior to the start of each passage A running calculation of the short term speech envel...

Страница 122: ...N Canada N0L 1G0 Page 8 USA 800 265 2093 519 268 3313 FAX 519 268 3256 www audioscan com Figure 8 Speech is detectable but not understandable if the 1 st percentile is at threshold Figure 9 When LTASS...

Страница 123: ...ectra LTASS for Speech Signals Average Effort re overall SPL for entire passage Hanning window 128 ms average 40 00 35 00 30 00 25 00 20 00 15 00 10 00 5 00 0 00 200 250 315 400 500 630 800 1000 1250...

Страница 124: ...re LTASS STANDARD 1 LEVEL re LTASS FEMALE 1 LEVEL re LTASS CHILD 1 LEVEL re LTASS ICRA Figure 12 Level of first percentile for Speechmap speech signals at average vocal effort 70th Percentile of 1 3 O...

Страница 125: ...Effort re LTASS for entire passage Hanning window 128 ms average 0 00 5 00 10 00 15 00 20 00 25 00 30 00 35 00 40 00 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 6300 8000 BAND...

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