2/18/2020 Housekeeping Webinar Experience Welcome! If not using speakers and you haven’t already, please call into the call center number 02 8518 1923 and enter access code 809 815 825 Judy dy Grob obste tein, AuD uD-FAAA, A, MAC ACAud Please be sure to keep microphones muted Manager of Education and Audiology If you have any questions, please type them in the chat box. You can view the chat box by clicking the chat bubble at the bottom of your screen Best option for audio is to call in using If you have any technical issues, please contact Dan Towns at Phone Number: 02 8518 1923 Access Code: 809 815 825 Dan_towns@starkey.com.au or call him direct at 02 8823 9005 For technical questions or log-in information please contact Dan Towns Direct line: 02 8823 9005 Dan_towns@Starkey.com.au Housekeeping Housekeeping Endorsed Session Learning Objectives Identify how to choose the appropriate acoustic options based on This Session is endorsed for ACAud, AudA and HAASA points the patient’s audiogram You must stay logged on for the full session Identify the different types of feedback and describe the approaches used to manage it in today’s hearing aids AudA members must complete a 10 questions quiz with a passing score of 70% as well as your CPD Reflections and Evaluations List two ways to differentiate a malfunctioning microphone from a ACAud, HAASA and NZAS members must complete the quiz to receive full points. malfunctioning receiver Agenda Back to the Basics Acoustic Component Feedback Options Troubleshooting Judy dy Grob obste tein, AuD uD-FAAA, A, MAC ACAud Manager of Education and Audiology 1
2/18/2020 Optimizing the Patient Journey Acoustic Options Choosing the correct acoustic options is an important tool for optimizing the patient journey with amplification 125 250 500 1K 2K 4K 8K 125 250 500 1K 2K 4K 8K -10 -10 0 OPEN 0 10 Audiometric Audiometric 10 20 20 LARGE 30 Factors Factors 30 40 40 MEDIUM 50 50 60 60 Acoustic Coupling Guidelines Venting Guidelines 70 SMALL 70 80 80 90 NO OR PRESSURE 90 100 100 0 RIC Custom Earmolds 5 10 Largest 15 20 Available 25 30 Audiometric 35 3 Vent 40 2 Vent Factors 45 Vent 50 55 1 Vent 750 Hz 60 65 70 Venting Guidelines 75 80 No Vent 85 90 or 1 Vent 95 100 105 110 2
2/18/2020 RIC Stock Earmolds Hearing Aid Gain Choosing the Right Matrix The difference between the input level and the output (in dB SPL) 20 2000 00 Hz “Amplification that allows a 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 person with hearing loss to hear, communicate, and participate 40 gain 50 gain 60 gain 70/71 gain 80 gain more fully in daily activities.” 3
2/18/2020 eSTAT : Starkey’s Proprietary Fitting Formula Power Requirements Emphasizes audibility for • Poor high frequency thresholds should speech understanding NOT be part of the equation Developed for Starkey’s proprietary • Don’t want high frequency gain to compression architecture overpower low frequencies Optimizes response modeling • Distortion and impact on sound quality regardless of hearing aid style Optimizes vent hearing aid interaction Feedback Feedback Squealing Management in Hearing Aid Whistle Ringing Technology Howling Screeching Humming Screaming Buzzing Feedback Mechanical Feedback Customs BTEs and RICs Occurs when the output of the receiver leaks out of the ear canal, ACOUSTIC enters the microphone and is reamplified • More susceptible • Less susceptible • Receiver and microphone are in the • Greater physical separation between same housing components Occurs when physical vibrations of the receiver diaphragm are direction, distance & size • Vibrational energy can lead to feedback • RIC receiver is moved out of the MECHANICAL transmitted back to the microphone diaphragm through contact instrument case with the hearing aid casing ELECTRONIC Occurs when there is a malfunction in the device’s circuitry 4
2/18/2020 Electronic Testing for Internal Feedback Feedback Seal the receiver off at the canal tip and hold the device up to the ear to listen - Malfunction in the components of any whistling will verify and confirm the device internal feedback. Solution involves opening the case and determining the source of the problem and possible replacement of • Fingertip the electronics of the device • Putty Requires attention from the • Listening stethoscope manufacturer Acoustic Feedback Acoustic Feedback Squeal • Sound wave from the receiver leaks back External Feedback Path to the microphone • Amplified signal – > reamplified • Undesired oscillations in the hearing aid create instability • Instability can lead to an audible sound Incoming Signal Microphone Amplifier Signal mixed Receiver that is usually unpleasant with feedback Factors Influencing the Factors Influencing Feedback Path the Feedback Path • Venting • Cerumen • Loose fit / Poor coupling • Hats, Scarves and other Head Coverings • Cracked or damaged earmold or shell • Jaw and head movements • Hugs • Improper alignment of the receiver • Coughing, chewing, sneezing, yawning, talking • Hearing aid gain • Positioning an object near the ear • Hand – inserting/removing the hearing aids 5
2/18/2020 Effects of Feedback Background Noise “ The most common reasons people stop 21% • Loudness Discomfort wearing or return their hearing aids are • Sound Annoyance because the device is physically uncomfortable • Distortion / Reduced Sound Quality or does not perform as well as expected… Feedback 17% • Reduced Speech Understanding Performance falls short of expectations when • Reduced Perceived Benefit of Amplification there is too much background noise, too much • Hearing aids don’t work well - Stigma ” feedback and/or poor sound quality. Sound Quality • Embarrassing 16% • Hearing aid rejection MarkeTrak 9 “Top Reasons No Longer Have Hearing Aid” Background Noise Feedback Sound Quality Feedback 12% 14% 10% Management MarkeTrak 10 Goals of Managing Feedback Feedback Management • Better physical fit and comfort • Make soft sounds more audible Acoustic Gain Feedback • Increase speech understanding Adjustments Reduction Cancellation • Improve sound quality • Better performance in all environments 6
2/18/2020 Acoustic Adjustments The Best Defense is a Good Offense Reduce the leakage of sound • Vent Diameter • Ear Impressions • Diameter of 1 st Bend • Coupling • Tubing Size • Alignment • Dome Size • Venting • Custom Earmolds • Stock Earmolds Complete vs Incomplete Impressions Good Ear Impressions Good Impression • Use cotton otoblocks Incomplete Impression Accurate • Capture the full concha bowl and helix Canal/Helix/Anti-Tragus yields better retention for proper alignment in the ear • Deep impression for CIC and IIC orders • Send new impressions with each order Better Sound Direction & Vent Good Impression Incomplete Impression Shell protrudes with poor impression Venting: Remember your cut off Earmolds/Domes 125 250 500 1K 2K 4K 8K 125 250 500 1K 2K 4K 8K When to replace: -10 -10 • Weight changes 0 0 OPEN 10 • Size changes 10 (children/surgery) 20 20 LARGE 30 • Hearing threshold changes 30 40 40 • Ear canal tissue stretching MEDIUM 50 50 • Damage 60 60 • Loose Fit SMALL 70 70 80 • Feedback 80 90 NO OR PRESSURE 90 100 100 7
2/18/2020 Gain Reduction Feedback Cancellation • Equally over all frequencies The premise behind feedback- cancellation algorithms is similar to • For the lowest input level that of noise cancelling headphones. (highest gain re: WDRC) It creates a copy of the feedback component and • In critical frequency regions where adds it out of phase to the input signal. feedback is expected to occur Hearing aid manufacturers have their Notch filtering - gain is reduced in narrow • own proprietary algorithms. frequency bands around critical frequencies Goals of Feedback Feedback Cancellation Cancellation 1 Feedback path is modeled mathematically 2 Subtracted from the microphone signal 3 Feedback is canceled • Achieve as much gain as possible over a External Feedback Path wide frequency range while eliminating feedback • Preserve audibility, speech intelligibility, + M sound quality, and comfort - • Do not allow processing artifacts that could degrade sound quality Incoming Signal Microphone Subtract mimicked Amplifier Signal mixed Receiver feedback with feedback • Low susceptibility to tonal signals/entrainment Feedback mimicked DSP by feedback canceller • Quickly adjust to feedback path changes Feedback Cancellation Static Filter • No gain reduction Static Feedback Cancellation Filter • Can improve the stability of the • Single filter applied hearing aid and provide additional gain • Based on area where the highest feedback potential exists Compared to an instrument setting that • Useful for stable environments where the feedback path won’t does not use feedback cancellation change • Effective with open fits and large • Ideal for eliminating entrainment vents • No artifact (warble) from output phase modulation • Static and Adaptive Filters • Artifacts • Entrainment 8
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