PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 659653

A note on simultaneous and interleaved masking.

I Hoffman·H Levitt
View original source ↗Export metadata ↓

Abstract

Speech and noise were switched periodically from ear to ear at a rate high enough to create a binaurally fused image. Two masking conditions were investigated. In one the speech and noise were switched in unison from ear to ear such that both speech and noise were presented simultaneoully to the same ear. In the other case, the speech and noise were interleaved such that there was no simultaneous overlap of the speech and noise at any one ear. The difference in masking levels between these two conditions was found to be on the order of 20 dB. The technique offers some interesting possibilities for investigating the relative effects of central and peripheral masking in both normal and hearing-impaired listeners.

Explore related subjects

Acoustic StimulationAdultAuditory PerceptionHumansPerceptual MaskingSpeechComparative StudyJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

I Hoffman, H Levitt. 1978. A note on simultaneous and interleaved masking.. https://doi.org/10.1016/0021-9924(78)90013-8

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1999

The magnitude and phase of temporal modulation transfer functions in cat auditory cortex.

Temporal modulation transfer functions (tMTFs) in response to periodic click trains are presented for simultaneous recordings from primary auditory cortex, anterior auditory field, and secondary auditory cortex in 21 cats. The multiunit records could be separated in to 215 single-unit spike trains that allowed a reliable estimate of a group delay, which represents the cumulative delay for responses to repetitive stimuli. For approximately two-thirds of the 215 single units the group delay was within 7.5 msec of the response latency to the first clicks in the trains. For the remaining units, the group delay was on average approximately 14 msec higher, and this may result from differences in synaptic properties. These findings were similar in the three cortical areas studied. The findings are modeled based on presynaptic facilitation and depression and pyramidal cell calcium kinetics, and a quantitative description of the magnitude of the tMTF was obtained that resulted in substantially shorter depression time constants (20 msec) than reported for visual cortex (300 msec). A small amount (0-5.5%) of facilitation that decayed with a time constant of 60 msec was obtained. Auditory cortical cells apparently have much faster recovery mechanisms than visual cortical cells. This allows for the ability of the auditory cortex to reliably track the rhythms that occur in natural sounds.

Acoustic Stimulation↗
PubMed1999

Gene disruption of p27(Kip1) allows cell proliferation in the postnatal and adult organ of corti.

Hearing loss is most often the result of hair-cell degeneration due to genetic abnormalities or ototoxic and traumatic insults. In the postembryonic and adult mammalian auditory sensory epithelium, the organ of Corti, no hair-cell regeneration has ever been observed. However, nonmammalian hair-cell epithelia are capable of regenerating sensory hair cells as a consequence of nonsensory supporting-cell proliferation. The supporting cells of the organ of Corti are highly specialized, terminally differentiated cell types that apparently are incapable of proliferation. At the molecular level terminally differentiated cells have been shown to express high levels of cell-cycle inhibitors, in particular, cyclin-dependent kinase inhibitors [Parker, S. B., et al. (1995) Science 267, 1024-1027], which are thought to be responsible for preventing these cells from reentering the cell cycle. Here we report that the cyclin-dependent kinase inhibitor p27(Kip1) is selectively expressed in the supporting-cell population of the organ of Corti. Effects of p27(Kip1)-gene disruption include ongoing cell proliferation in postnatal and adult mouse organ of Corti at time points well after mitosis normally has ceased during embryonic development. This suggests that release from p27(Kip1)-induced cell-cycle arrest is sufficient to allow supporting-cell proliferation to occur. This finding may provide an important pathway for inducing hair-cell regeneration in the mammalian hearing organ.

Acoustic Stimulation↗
PubMed1999

Sensory gating of the P13 midlatency auditory evoked potential and the startle response in the rat.

The human P1/P50 midlatency auditory evoked potential and the startle response (SR) have been used as measures of sensory and sensorimotor gating, respectively. In the present study, both prepulse and paired stimulus paradigms were used in order to investigate the relationship between sensory gating mechanisms of the P13 potential, the putative rodent equivalent of the P1 potential, and those of the SR. In addition, these were compared to the properties of the N40 potential, another measure of sensory gating. Simultaneous recordings from the vertex (P13 potential and N40 potential) and neck musculature (SR) showed that (1) in a prepulse paradigm, increasing the intensity of the prepulse or decreasing the interstimulus interval resulted in increased inhibition of the P13 potential, N40 potential (to a lesser degree) and the SR (to a greater degree), (2) when using a low signal-to-noise ratio between the prepulse intensity and the background level, prepulse inhibition of the SR was reduced or absent while that of the P13 potential was present, (3) the amplitude of the 'prepulse evoked' P13 potential was significantly correlated with prepulse inhibition of the P13 potential, the N40 potential and the SR, (4) in a paired identical stimulus paradigm, decreasing the interstimulus interval resulted in increased habituation of the P13 potential, N40 potential (to a lesser degree) and the SR, and (5) increasing the intensity of the paired stimulation resulted in increased habituation of the P13 potential and the N40 potential (to a lesser degree), but not of the SR. These results demonstrate the presence of prepulse inhibition of the P13 potential, the N40 potential and the SR in a parallel manner, but show certain specific differences in their responses to parametric changes.

Acoustic Stimulation↗