The Use of Psychophysical Tuning Curves to Explore Dead Regions in the Cochlea

Moore, Brian C. J.; Alcántara, Joseph I.

doi:10.1097/00003446-200108000-00002

Cited by 112 publications

(99 citation statements)

References 28 publications

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“…Modified masking TCs, such that maximally efficient masking frequencies are below the probe frequency, have already been reported in two conditions: the so-called "hypersensitivity of the tail" (7) and "off-frequency detection" (4).…”

Section: Discussionmentioning

confidence: 99%

“…Frequency shifts of TC dips, less common, are considered to reflect off-frequency hearing (3, 4), a condition reported in patients with dead cochlear zones defined as cochlear intervals in which IHCs and/or associated neurons are nonfunctional. However, intense sound stimulations may be detected in cochlear regions adjacent to dead zones, inferred from the position of where the masking-TC dips have shifted (4). About 60% of deaf people with a hearing threshold above 70 dB have cochlear dead regions (4).…”

Section: Significancementioning

confidence: 99%

“…However, intense sound stimulations may be detected in cochlear regions adjacent to dead zones, inferred from the position of where the masking-TC dips have shifted (4). About 60% of deaf people with a hearing threshold above 70 dB have cochlear dead regions (4).…”

Section: Significancementioning

confidence: 99%

“…In normal healthy ears, maximum masking occurs when the frequency of at least one of the two interfering sounds, the probe or the masker, coincides with the CF of the cochlear place where the masking effect is generated (2,4,6). In an active cochlea, the BM vibration for intermediate stimulus intensities (20-80 dB SPL) undergoes compressive amplification of its displacements solely at the CF place of the stimulus, where it increases by only about 0.3 dB/dB increase of sound level in the ear canal.…”

Section: Masking Tuning Curves For Midhigh Frequency Sounds Display Mmentioning

confidence: 99%

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An unusually powerful mode of low-frequency sound interference due to defective hair bundles of the auditory outer hair cells

Kamiya

Michel

Giraudet

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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A detrimental perceptive consequence of damaged auditory sensory hair cells consists in a pronounced masking effect exerted by low-frequency sounds, thought to occur when auditory threshold elevation substantially exceeds 40 dB. Here, we identified the submembrane scaffold protein Nherf1 as a hair-bundle component of the differentiating outer hair cells (OHCs). Nherf1 −/− mice displayed OHC hair-bundle shape anomalies in the mid and basal cochlea, normally tuned to mid-and high-frequency tones, and mild (22-35 dB) hearing-threshold elevations restricted to midhigh sound frequencies. This mild decrease in hearing sensitivity was, however, discordant with almost nonresponding OHCs at the cochlear base as assessed by distortion-product otoacoustic emissions and cochlear microphonic potentials. Moreover, unlike wild-type mice, responses of Nherf1 −/− mice to high-frequency (20-40 kHz) test tones were not masked by tones of neighboring frequencies. Instead, efficient maskers were characterized by their frequencies up to two octaves below the probe-tone frequency, unusually low intensities up to 25 dB below probe-tone level, and growth-ofmasker slope (2.2 dB/dB) reflecting their compressive amplification. Together, these properties do not fit the current acknowledged features of a hypersensitivity of the basal cochlea to lower frequencies, but rather suggest a previously unidentified mechanism. Low-frequency maskers, we propose, may interact within the unaffected cochlear apical region with midhigh frequency sounds propagated there via a mode possibly using the persistent contact of misshaped OHC hair bundles with the tectorial membrane. Our findings thus reveal a source of misleading interpretations of hearing thresholds and of hypervulnerability to low-frequency sound interference.off-frequency detection | Usher syndrome | hearing impairment | Nherf2 | tail hypersensitivity M ammalian hearing displays remarkable sensitivity, fine temporal acuity, and exquisite frequency selectivity, which contribute to auditory scene analysis and speech intelligibility. The first steps of sound processing, i.e., sound wave detection and neuronal encoding in the cochlea, are performed by two populations of hair cells, the inner hair cells (IHCs) and the outer hair cells (OHCs). These cells are sandwiched between the underlying basilar membrane (BM) and the overlying tectorial membrane (TM) (SI Appendix, Fig. S1A). IHCs are the genuine sensory cells that transduce the sound stimuli into electrical signals in the primary auditory neurons. OHCs are mechanical effectors that amplify the sound-evoked movements of the cochlear partition, sharpen its frequency selectivity, and produce waveform distortions (1, 2). A pure-tone stimulus entering the cochlea elicits a traveling wave that propagates along the BM from the cochlear base toward its apex, increasing in amplitude until it peaks at a characteristic place, where the mechanical properties of the cochlea are best tuned to the stimulus frequency. Beyond this characteristic place, the ampl...

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Section: Discussionmentioning

confidence: 99%

Section: Significancementioning

confidence: 99%

Section: Significancementioning

confidence: 99%

Section: Masking Tuning Curves For Midhigh Frequency Sounds Display Mmentioning

confidence: 99%

See 2 more Smart Citations

An unusually powerful mode of low-frequency sound interference due to defective hair bundles of the auditory outer hair cells

Kamiya

Michel

Giraudet

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…A dead region can be characterised in terms of the characteristic frequencies of the IHCs or neurones bordering that region. Dead regions can be diagnosed using by measuring psychophysical tuning curves (PTCs, see Thornton and Abbas, 1980;Florentine and Houtsma, 1983;Turner et al, 1983;Moore and Alca antara, 2001). A simpler test for use in the clinic has been described by Moore et al (2000).…”

Section: Dead Regionsmentioning

confidence: 99%

Speech processing for the hearing-impaired: successes, failures, and implications for speech mechanisms

Moore

2003

Speech Communication

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People with sensorineural hearing impairment typically have more difficulty than normally hearing people in understanding speech in the presence of background sounds. This paper starts by quantifying the magnitude of the problem in various listening situations and with various types of background sound. It then considers some of the factors that contribute to this difficulty, including: reduced audibility; reduced frequency selectivity; loudness recruitment; and regions in the cochlea which have no surviving inner hair cells and/or neurones (dead regions). Methods of compensating for the effects of some of these factors are described and evaluated. Signal-processing methods to compensate for the effects of reduced frequency selectivity using the output of a single microphone have had only limited success, although methods using multiple microphones have worked well. Amplitude compression can compensate for some of the effects of loudness recruitment, allowing speech to be understood over a wide range of sound levels. The exact form of the compression (fast-acting versus slow-acting, single-channel versus multiple channel) does not seem to be critical, suggesting that the relative loudness of different components of speech, and dynamic aspects of loudness perception do not need to be restored to ''normal''.

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References

2007

Cochlear Hearing Loss

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The Use of Psychophysical Tuning Curves to Explore Dead Regions in the Cochlea

Cited by 112 publications

References 28 publications

An unusually powerful mode of low-frequency sound interference due to defective hair bundles of the auditory outer hair cells

An unusually powerful mode of low-frequency sound interference due to defective hair bundles of the auditory outer hair cells

Speech processing for the hearing-impaired: successes, failures, and implications for speech mechanisms

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