Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pitch Perception”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,567 records · Page 87Linked to original sources
PubMed2004

Correlated brain stem and cortical evoked responses to auditory tone change.

Numerous human studies have separately observed the effects of auditory stimuli at brain stem and cortical levels, but little research has focused on possible functional coupling between these diverse brain areas. The present study recorded the cortical C-process [5] evoked by a pitch change between two successive tones, as well as the brain stem frequency-following response (FFR) evoked by each tone. The results replicated expected C-process component waveforms, including a late, negative (N2) component. FFR spectral intensity differences between the two tones were significantly correlated with N2 amplitude. These results suggest that signal processing reflected in long-latency auditory evoked response components is not exclusively a cortical phenomenon, but also depends upon patterns of neural processing occurring in brain stem pathways.

Acoustic Stimulation↗
PubMed2005

MEG responses to rippled noise and Huggins pitch reveal similar cortical representations.

The onset of pitch within an ongoing noise signal evokes a particular brain activity, the pitch onset response (POR). Using whole-head MEG, PORs to iterated rippled noise (IRN) and Huggins pitch (HP), representing prototypical pitch-in-noise signals, were measured in twenty subjects during a pitch identification task (333 Hz, 400 Hz, randomized). HP and IRN yielded similar responses, lateralized to the left hemisphere and peaking about 180 ms after pitch onset. The initial phase (140 ms) showed stronger activations to 400 than to 333 Hz whereas later stages (200-300 ms) showed target vs nontarget effects. These results suggest, first, that different pitches converge into a common cortical representation and, second, that the POR encompasses various successive processing stages.

Acoustic Stimulation↗
PubMedDate not supplied

Comparison between AER and behavioral thresholds in normally and abnormally hearing chinchillas.

The present study compared the auditory evoked response (AER) and behavioral thresholds from the chinchilla before and after acoustic overstimulation. Bipolar electrodes were chronically implanted in the inferior colliculus of seven monauralized behaviorally conditioned animals (shock-avoidance). AER to 20-msec and behavioral thresholds to 20- and 500-msec tone bursts were determined for a range of frequencies before and after a 4-hour exposure to a 2000 Hz, 120dB SPL pure tone for six of the animals. One animal served as control and received no exposure. Results revealed a relatively close correspondence between AER and behavioral thresholds both before and after noise exposure in the same animal. Postexposure AER and behavioral thresholds displayed mild to moderate losses in sensitivity in the 1 to 4 kHz range. These findings justify further development of this particular AER as an indicator of hearing sensitivity in the chinchilla.

Animals↗
PubMedDate not supplied

Acoustic reflex thresholds: variability and distribution effects.

Acoustic reflex thresholds (ARTs) at 500, 1000, and 2000 Hz from 1833 ears were subjected to multiple linear regression analyses using a stepwise inclusion model to determine the effects of hearing losses in the 500- to 4000-Hz range for each of the activators. Although statistically significant regression equations were developed, these accounted for only 1 to 47% of the variance of ART levels. In light of the wide variance of ARTs unexplainable directly from audiometric data, it was deemed more appropriate to consider the range of ARTs from the standpoint of the sampling distribution of ARTs as a function of hearing level. Deciles were calculated in the 10th through 90th percentile ranges. These data corroborate and expand upon previously reported material on the distributions of ARTs among ears with normal hearing and cochlear impairment.

Adolescent↗
PubMedDate not supplied

Acoustic reflex temporal summation measured at threshold.

This study measured the threshold of the acoustic reflex as a function of reflex-activating stimulus duration. Acoustic reflex thresholds (ARTs) were measured for tonal stimuli at frequencies of 1000 and 3000 Hz and broadband noise at six durations between 20 and 500 msec for both normal and hearing-impaired subjects. Traditional techniques and response averaging were used. Results suggest that these methods have a significant influence on ART and reflex temporal summation at threshold. Lowest thresholds and almost no temporal summation were found with a response averaging technique and a bidirectional shift criterion, whereas clinical procedures yielded highest thresholds and greater summation. These results suggest a need to examine the methodology used for measurement of the acoustic reflex and the interpretation of clinical pathology based on measurements of reflex temporal summation.

Adult↗
PubMedDate not supplied

The verbotonal method for management of young, hearing-impaired children.

The verbotonal method is effective for establishing good spoken language and listening skills. It is based on a developmental model of normal-hearing children, and emphasizes the importance of developing good rhythm, intonation and voice quality in hearing-impaired children. Specifically trained teachers/clinicians are combined with high quality amplification and vibrotactile input with System Universal Verbotonal Audition Guberina units. These units provide a wide frequency response with the option of modifying the frequency response through the cutoff frequency and slopes of filters to emphasize the optimal field of hearing of each hearing-impaired child. Through intensive intervention the rhythm and intonation patterns and the listening skills develop simultaneously. The goal is to integrate hearing-impaired children into regular educational and social situations. The integration rates are between 60 and 90%. The parents role is more supportive than therapeutic, and is designed to meet the needs and skills of each parent.

Child↗
PubMedDate not supplied

Human auditory steady state evoked potentials during sleep.

The human auditory steady state evoked potentials were recorded during all-night sleep in 10 subjects. The effects of stimulus rate and intensity on these potentials were measured using on-line Fourier analysis. The amplitude of the response was greatest at stimulus rates of 30 to 50/sec. Although the response amplitude was lower during sleep, the rate at which the amplitude was greatest did not change between sleep and wakefulness. As the intensity was increased above threshold, the amplitude of the response increased linearly. The responses recorded during wakefulness showed a larger amplitude change with increasing intensity than during sleep. The estimated thresholds for the responses, however, did not differ significantly between wakefulness and sleep.

Adult↗
PubMed1986

The National Acoustic Laboratories' (NAL) new procedure for selecting the gain and frequency response of a hearing aid.

A new procedure is presented for selecting the gain and frequency response of a hearing aid from pure-tone thresholds. This was developed from research which showed that a previous procedure did not meet its aim of amplifying all frequency bands of speech to equal loudness but that frequency responses which did so were considerably more effective. Measurements of 30 sensorineurally hearing-impaired ears (27 subjects), together with data from other studies, were analyzed to determine the best formula for predicting the optimal frequency response, for each individual, from the audiogram. The analysis indicated that a flat audiogram would require a rising frequency response characteristic of about 8 dB/octave up to 1.25 kHz and thereafter a falling characteristic of about 2 dB/octave. Variations in audiogram slope required about one-third as much variation in response slope. Three frequency average (3FA) gain was calculated to equal the 3FA gain of the previous procedure. Forty-four subjects (67 aided ears) fitted by the new procedure were evaluated by paired comparison judgments of the intelligibility and pleasantness of speech. The prescribed frequency response was seldom inferior to, and usually better than, any of several variations having more, or less, low and/or high-frequency amplification. On the average, used gain was approximately equal to prescribed gain. It is concluded that the new formula should prescribe a near optimal frequency response with few exceptions.

Audiometry, Pure-Tone↗
PubMed1987

Functional gain.

The concept of functional gain was popularized by Pascoe in 1975, and for some time was one of the most popular hearing aid evaluation techniques. More recently probe tube systems for measuring insertion gain have become popular, and some questions regarding the continued utility of functional gain have been raised. In this paper some of the major advantages and disadvantages of functional gain are reviewed. While functional gain is subject to contamination from noise external or internal to the hearing aid, it does provide subjective information not available from insertion gain.

Acoustics↗
PubMed1987

Representations of the long-term spectra of speech.

Numerous and somewhat different representations of the long-term spectra of speech are available in the literature. Various estimates of speech spectra have been converted to a consistent audiogram format for presentation here. Even so, plots of speech spectral levels across the frequency region of 125 to 8000 Hz vary considerably. Bases for some of these variations and clinical utilization of a speech spectrum are discussed.

Auditory Threshold↗
PubMed1987

Factors which affect measures of speech audibility with hearing aids.

Speech audibility may be defined as that proportion of a speech spectrum which is above a person's threshold. To optimize speech audibility with a hearing aid, several measures are needed. These include quantification of a speech spectrum, measures of hearing sensitivity, and measures of the "real ear" gain of the hearing aid. Some procedural factors must be considered to obtain adequate measures in a typical clinical setting. Those considered here are: (1) a modified Articulation Index to quantify a speech spectrum, (2) specification of hearing sensitivity with a narrowband sound field reference where the out-of-band rejection rate of the sound field stimulus is greater than twice the slope of the hearing loss, and (3) use of functional gain (measured directly or estimated using earphone and sound field results provided that the sound field stimulus has the required characteristics for measuring hearing sensitivity in the sound field) as a measure of the real ear gain of the hearing aid. Guidelines are given for the practical measurement of speech audibility in a typical clinical setting. The guidelines are appropriate for all measures of real ear gain including those obtained with all probe tube systems.

Audiometry, Pure-Tone↗
PubMed1988

Frequency dependence of interear asymmetries and binaural interaction in the human ABR.

In the present study derived auditory brain stem responses utilizing high pass masking were used to determine the frequency dependence of interear asymmetries and binaural interaction. Eight female adults with normal hearing participated in this study. The ABR was recorded for right and left ears and binaurally with clicks alone and in the presence of high pass masking noise with the following cutoff frequencies: 4000, 2000, 1000, and 500 Hz. Derived responses were obtained by successive waveform subtractions and were analyzed for significant right/left asymmetries, for latency and amplitude, utilizing a statistical method discussed by Spivak (unpublished doctoral dissertation, City University of New York, 1985). The binomial test revealed that the frequency of latency and amplitude asymmetries was not significantly above chance levels for the unmasked measures or for any of the derived bandwidth measures. The binaural interaction component (BIC) was obtained utilizing the method proposed by Dobie and Berlin (Arch Otolaryngol 1979; 105:391-398), and was expressed as a percentage of the true binaural. Analysis of variance revealed no significant differences in the ratio of the BIC amplitude to the true binaural amplitude as a function of the high pass masking cutoff frequency. The present data suggests that for the frequency bandwidths analyzed in this study, there are no specific frequency dependencies of interear asymmetries or binaural interaction in the human ABR.

Adult↗
PubMed1989

Effect of text complexity on connected discourse tracking rate.

The effect of three levels of text complexity upon connected discourse tracking rates was investigated in normal listeners who tracked by lipreading alone and by lipreading with auditorily presented voice pitch. Text complexity affected connected discourse tracking under both lipreading conditions, with tracking rates decreasing as the level of text complexity increased. The improvement in tracking rate with the addition of voice pitch information was found to be invariant over changes in text complexity when expressed as a simple difference between the two tracking rates.

Female↗
PubMed1990

Pitch scaling and speech understanding by patients who use the Ineraid cochlear implant.

Pitch scaling was assessed for 10 normal-hearing listeners and 8 patients who use the Ineraid multichannel cochlear implant. For two patients who were excellent users of the prosthesis, pitch increased over a wide range of frequencies (100 Hz to 2333-3000 Hz). For three patients who were above average users of the prosthesis, pitch increased with frequency over a smaller range (100 Hz to 1200-2300 Hz). For three patients who demonstrated poor word recognition ability, pitch increased with frequency over a very small range (100 Hz to 600-1000 Hz). These results suggest that differences in speech understanding among patients who use the Ineraid may be accounted for, in part, by the range of pitch available through the implant.

Acoustics↗
PubMed1991

Single-channel versus bilateral multichannel cochlear implant results: a case report.

Pre- and postoperative audiologic findings are compared in a patient who underwent three cochlear implant surgeries: an initial single-channel device in a recently deafened ear with no residual hearing, followed by a multichannel device in a congenitally deafened ear with a severe to profound loss, and subsequent explantation of the single-channel device and reimplantation with a multichannel device.

Audiometry, Speech↗
PubMed1991

Individual differences in speech recognition ability: implications for hearing aid selection.

Hearing-impaired listeners with similar audiometric configurations often demonstrate varying abilities to understand speech in the presence of noise and/or reverberation. To date, however, it is unclear which auditory mechanisms are responsible for these perceptual deficits. This lack of information is unfortunate, as individual susceptibility to noise and reverberation may explain why hearing-impaired listeners receive varying degrees of benefit from rehabilitative strategies. The present discussion will examine: (1) individual speech recognition susceptibility to noise and reverberation in hearing-impaired listeners and (2) auditory and cognitive hypotheses to explain individual differences in speech recognition performance. Theoretical and clinical implications for hearing aid selection procedures will be discussed.

Hearing Aids↗
PubMed1993

Speech spectra for six recorded monosyllabic word tests.

Speech spectra (long-term RMS levels and 1% speech peaks) in third-octave bands were determined for six monosyllabic word test materials: digital recordings of the Central Institute for the Deaf W-22 word test and the Northwestern University NU-6 word test obtained from Qualitone; audiotape recordings of the Central Institute for the Deaf W-22 word test, the Northwestern University NU-6 word test, and the Harvard Psycho-Acoustic Laboratory PB-50 word test obtained from Auditec of St. Louis; and an audio-tape recording of the Maryland CNC word test obtained from Olsen Distributors. The spectra were generally within 2 SD of previous results for continuous speech spoken by an average male talker (Cox, Matesich, & Moore, 1988; Cox & Moore, 1988), but differed sufficiently from those data and from one another to affect the accuracy of Articulation Index calculations. The relationship between the level of the calibration tone and the speech in the third-octave band centered at 1000 Hz was different for each recording.

Acoustic Stimulation↗