Lecture 15 Flashcards
Place Coding of Sound
Different portions of the basilar membrane are more sensitive to sounds of different frequencies
-Valid for low + high frequencies
Time Coding of Sound
Auditory nerve firing is also ‘‘phase-locked’’, i.e. neurons systematically fire at a given time point of te cycle
-Only valid for low frequencies
Audiometry
Measure of how good or bad someone’s hearing is
-Map out the minimal sound needed
nearly perfect noise clarity
A discrimination of 96% would indicate…
a loss of noise clarity
A discrimination of 84% would indicate…
Treatment Avenues for Hearing Loss
-Hearing aid
-Cochlear implant
-Surgery
-Medication/antibiotics
Hearing Aid
-Sound amplifiers
-Microphone that amplifies sound
Hearing Aid Design
-In-the-ear (ITE) hearing aid
-Behind-the-ear (BTE) hearing aid
Amplifying Hearing Aids
Adjust volume to push certain frequencies
-Directional microphones (focus on speech)
-Noise-cancelling algorithms (cancel background noises)
Hearing Aid Fit Check
Validation of acoustic output at the tympanic membrane
Cochlear Implant (CI)
-Electrode inserted inside cochlea
-Stimulate
-Shoot electricity on the nerve
-Place-coding
-Microphone on outside piece
-Attached to head by magnet
Candidacy for Cochlear Implant
Candidacy assesment for cochlear implant is indicated for patients showing 60/60 (loudness/clarity)
Electro-Acoustic Stimulation (EAS)
-Acoustic stimulation
-Electric stimulation
-Hybrid loss
-Combine both
-Overlap provides a smooth transition
patient is completely deaf
A discrimination of 10% indicates…
Acute phase post-activation of the CI
More reports of high-pitched sound in 18-24 mm electrode users vs. 26-31 mm electrode users
Chronic phase 4-8 years post-activation of the CI
Similar number of reports of high-pitched sound in 18-24 mm electrode users and 26-31 mm electrode users
Anatomy-based Fitting
Electrode contact site as per CT scan
-Realized in the last year 1/2 that we weren’t doing a great job
Anatomy-based fitting improves speech recognition in bilateral CI users
-ABF improves speech recognition in quiet and in noise in experienced bilateral CI users
-2 ears mismatched
-2 cochlear implants
-Neural placisity will not fully adapt in this case
Single-Sided Deafness (SSD)
If electrode of deaf ear is not placed well… patient stps wearing it and says ‘‘not as good as my other ear’’
Hearing Handicap in Single-Sided Deafness
-Recognition deficit for speech signal in the ipsilesional auditory hemifield
-Speech-in-noise recognition deficit
-Sound localization deficit
-Listening effort
Pupillometric Measure of Listening Effort
-Eye tracking
-More cognitive effort = more pupil dialates
Anatomy-based fitting improves speech recognition in EAS CL users
ABF improves speech-in-quiet recognition in patients newly implanted with a unilateral EAS CI
Partial Alleviation of Hearing Handicap by Anatomy-based fitting in bilaterally deaf patients using unilateral CI
-ABF FAILS to improve speech recognition in quiet or in noise in bilaterally deaf patients newly implanted with a unilateral CI, even after 9 months of use
-ABF IMPROVES speech recognition in noise, but not in quiet, in bilaterally deaf patients newly-implanted with unilateral CI
-ABF IMPROVES speech reognition in quiet and in noise when introduced in bilaterally deaf patients wih long-standing use of a unilateral CI
Anantomy-based fitting improves music perception in bilaterally deaf patients using a unilateral CI
-Subjective quality rating of music samples
-Melodic contour identification
-Familiar song appreciation
-Place coding
