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 37 records · Page 2Linked to original sources

Measurement of pitch in speech: an implementation of Goldstein's theory of pitch perception.

Recent developments in hearing theory have resulted in the rather general acceptance of the idea that the perception of pitch of complex sounds is the result of the psychological pattern recognition process. The pitch is supposedly mediated by the fundamental of the harmonic spectrum which fits the spectrum of the complex sound optimally. The problem of finding the pitch is then equivalent to finding the best harmonic match. Goldstein [J. Acoust. Soc. Am. 54, 1496-1516 (1973)] has described an objective procedure for finding the best fit for stimuli containing relatively few spectral components. He uses maximum likelihood criterion. Application of this procedure to various data on the pitch of complex sounds yielded good results. This motivated our efforts to apply the pattern recognition theory of pitch to the problem of measuring pitch in speech. Although we were able to follow the main line of Goldstein's procedure, some essential changes had to be made. The most important is that in our implementation not all spectral components of the complex sound have to be classified as belonging to the harmonic pattern. We introduced a harmonics sieve to determine whether components are rejected or accepted at a candidate pitch. A simple criterion, based on the components accepted and rejected, led to the decision on which candidate pitch was to be finally selected. The performance and reliability of this psychoacoustically based pitch meter were tested in a LPC-vocoder system.

Humans↗

Binaural pitch perception in normal-hearing and hearing-impaired listeners.

The effects of hearing impairment on the perception of binaural-pitch stimuli were investigated. Several experiments were performed with normal-hearing and hearing-impaired listeners, including detection and discrimination of binaural pitch, and melody recognition using different types of binaural pitches. For the normal-hearing listeners, all types of binaural pitches could be perceived immediately and were musical. The hearing-impaired listeners could be divided into three groups based on their results: (a) some perceived all types of binaural pitches, but with decreased salience or musicality compared to normal-hearing listeners; (b) some could only perceive the strongest pitch types; (c) some were unable to perceive any binaural pitch at all. The performance of the listeners was not correlated with audibility. Additional experiments investigated the correlation between performance in binaural-pitch perception and performance in measures of spectral and temporal resolution. Reduced frequency discrimination appeared to be linked to poorer melody recognition skills. Reduced frequency selectivity was also found to impede the perception of binaural-pitch stimuli. Overall, binaural-pitch stimuli might be very useful tools within clinical diagnostics for detecting specific deficiencies in the auditory system.

Adult↗

Pure tone pitch perception and low-frequency hearing loss.

Pitch perception for pure tones was investigated in a group of listeners with low-frequency sensorineural hearing loss. Pitch judgments from each listener were compared with results from psycho-acoustic tasks which provide information on the "place" of cochlear response. The pitch measures employed were: (1) binaural pure-tone pitch matching in a listener with unilateral hearing loss, (2) octave judgments in listeners with musical ability, and (3) pitch-intensity functions in other listeners. Cochlear place of response was inferred from psychophysical tuning curves (PTC's). Two distinct types of PTC's for low-frequency probe tones were observed. Three listeners demonstrated "abnormally tuned" PTC's. For these listeners the frequencies that were most effective at masking the probe were considerably higher than the probe frequency. The three remaining listeners demonstrated "normally tuned" PTC's. Listeners with abnormally tuned PTC's were suspected of having an extremely abnormal place of response for low-frequency tones; this response pattern being located more toward the base of the cochlea than in the listeners with normally tuned PTC's. Sensitivity thresholds measured in the presence of high-pass masking noise supported this hypothesis. Small pitch-frequency irregularities were observed in many listeners, although they were not consistently related to the inferred place of response for that frequency. The individual listeners' pitch judgments failed to distinguish between two types of PTC's. In particular, listeners who demonstrated abnormally tuned PTC's did not exhibit correspondingly large pitch irregularities. These results are difficult to explain on the basis of a classical "place" theory of pitch perception.

Adult↗

Pitch perception: a dynamical-systems perspective.

Two and a half millennia ago Pythagoras initiated the scientific study of the pitch of sounds; yet our understanding of the mechanisms of pitch perception remains incomplete. Physical models of pitch perception try to explain from elementary principles why certain physical characteristics of the stimulus lead to particular pitch sensations. There are two broad categories of pitch-perception models: place or spectral models consider that pitch is mainly related to the Fourier spectrum of the stimulus, whereas for periodicity or temporal models its characteristics in the time domain are more important. Current models from either class are usually computationally intensive, implementing a series of steps more or less supported by auditory physiology. However, the brain has to analyze and react in real time to an enormous amount of information from the ear and other senses. How is all this information efficiently represented and processed in the nervous system? A proposal of nonlinear and complex systems research is that dynamical attractors may form the basis of neural information processing. Because the auditory system is a complex and highly nonlinear dynamical system, it is natural to suppose that dynamical attractors may carry perceptual and functional meaning. Here we show that this idea, scarcely developed in current pitch models, can be successfully applied to pitch perception.

Acoustic Stimulation↗

Carbamazepine-induced abnormal pitch perception.

A 7-year-old boy began to complain that his pitch perception was decreased just after oral medication with carbamazepine was initiated for the treatment of epilepsy. When he played the piano, he felt as if he had played a musical note of almost a half pitch lower than he had. His pitch perception recovered soon after the cessation of carbamazepine. A 14-year-old girl noted a lowered pitch of music sounds while she played the piano just after the administration of carbamazepine for the treatment of epilepsy. Carbamazepine was withdrawn and the auditory symptoms disappeared. Both patients were musically trained. Reversible pitch perception abnormalities are a rare adverse effect of carbamazepine, however, the clinical features of the reported cases were similar; they were musically trained, young, female and Japanese. Although the mechanism remains unclear, we have to pay attention to this subtle adverse effect when we treat epileptic patients with carbamazepine.

Administration, Oral↗

Characterization of deficits in pitch perception underlying 'tone deafness'.

Congenital amusia is a disorder characterized by life-long, selective deficits in the perception of music. This study examined pitch-perception abilities in a group of 10 adults with this disorder. Tests were administered that assessed fine-grained pitch perception by determining thresholds both for the detection of continuous and segmented pitch changes, and for the recognition of pitch direction. Tests were also administered that assessed the perception of more complex pitch patterns, using pitch-sequence comparison tasks. In addition, the perceptual organization of pitch was also examined, using stream segregation tasks that assess the assignment of sounds differing in pitch to one or two distinct perceptual sources. In comparison with 10 control subjects, it was found that the participants with congenital amusia exhibited deficits both at the level of detecting fine-grained differences in pitch, and at the level of perceiving patterns in pitch. In contrast, no abnormalities were identified in the perceptual organization of pitch. The pitch deficits identified are able to account for the music perception difficulties in this disorder, and implicate deficient cortical processing.

Acoustic Stimulation↗

Observation of a reversible, medication-induced change in pitch perception.

This paper reports a study of an absolute pitch possessor who, upon administration of the psychoactive drug Tegratol (carbamazepine), experienced a significant change in her pitch perception. The subject's performance both in producing, as well as in identifying, random-frequency tones was measured, covering the period of administration of the drug, as well as control periods before and after. The main effect of the drug was a downward shift of the perceived pitch as compared to the two control periods. The magnitude of the shift was observed to increase with increasing fundamental frequency of the stimulus; the average shift was about one semitone. Detailed results on the frequency dependence and time dependence of the pitch shifts are presented. This may be the first documented report of a significant, reversible change of pitch perception caused by a medication.

Acoustic Stimulation↗

The role of intensity upon pitch perception in cochlear implant recipients.

OBJECTIVES: Pitch plays a key role in the perception of speech and music, the recognition of a speaker's voice, and in analyzing complex auditory patterns. To date, little consideration has been given to the influence of stimulation level on pitch perception. The aim of this study was to investigate the impact of a sound's intensity on pitch perception in cochlear implant recipients using monopolar stimulation. STUDY DESIGN: Thirteen patients with an average implant use of 4.13 years took part in this study. All patients were implanted with MedEl Combi 40/40+ cochlear implants. METHODS: In the first part of the study, we performed a pitch ranking procedure to confirm that all patients were able to judge pitch changes. Using a visual scale, study participants were then asked to compare the pitch of an intensity-constant reference tone with the pitch of a test tone of varying intensity. RESULTS: Eleven (85%) patients were found to perceive a clear change in pitch with changing stimulus intensity. Statistical analysis showed a strong positive correlation in 10 patients (correlation coefficients between 0.99 and 0.71) and a strong negative correlation in 1 patient (r = -0.92). CONCLUSIONS: The results suggest that a distinct relationship exists between pitch perception and intensity of the stimulus. To date, speech coding strategies do not support these findings. Nevertheless, we believe that for the optimized most natural perception of sounds, especially music, the described particularities of pitch perception need to be respected, and further investigations on this topic are necessary.

Acoustic Stimulation↗

[Modeling of auditory mechanisms of pitch perception].

A hypothesis of two subordinately interconnected pitch perception systems is put forward and described. The leading system is responsible for the analysis of periodical sequences of spikes along audioneurons whose generation moments are synchronized by the acting sound oscillations. This system allows measuring of any periodical sound--simple or complex--including the residual sound. However, the system of periodicity analysis does not ensure the experimentally determined precision of pitch change perception. It is shown that the signal distribution along the basilar membrane enables the activation of the second system which analyses the spatial--temporal image by means of a great number of well innervated internal receptor cells. This system functioning is characterized by small values of differential threshold pitches, since as a discriminatory characteristic a curt decline of the basilar membrane oscillation envelope is used which is formed after a prolonged sinusoidal sound.

Basilar Membrane↗

Pitch perception: a difference between right- and left-handed listeners.

Various results indicate that the perception of a complex tone's "virtual" pitch is generally lateralized in the right cerebral hemisphere. The primary aim of this work was to test the hypothesis that this is not the case for the "spectral" pitch percepts induced by complex tones. Forty right-handed and 18 left-handed listeners were monaurally presented with pairs of successive tones made up of n consecutive equal-amplitude harmonics of a missing fundamental (F0). n varied from two to four across subjects. In "test" conditions, the paired tones differed in F0 but the spectral components of the tone with the lower F0 were higher in frequency than the corresponding components of the other tone (except for one component, which was identical). The subjects had to say if, from one tone to the other, pitch rose or fell. From such judgements, one could infer that the pitch dominantly perceived in each tone was a virtual pitch (corresponding to F0) or a spectral pitch (i.e., the pitch of a single spectral component, or a perceptual quality corresponding to the centroid of the power spectrum). For n = 2, the results indicated that virtual pitch was less salient than spectral pitch; the opposite occurred for n = 3 and n = 4. The ear (left or right) to which the stimuli were presented had some influence on the judgements, in the expected direction. However, this influence was not a robust one. Unexpectedly, a reliable effect of the listeners' handedness was observed: for each value of n, the judgements indicating virtual pitch perception were less frequent in the left-handers than in the right-handers. Discrimination performances measured in "control" conditions showed that the handedness factor was not confounded with a factor of frequency discrimination ability.

Acoustic Stimulation↗

Carbamazepine-induced transient auditory pitch-perception deficit.

This report presents six cases of transient auditory disturbance caused by carbamazepine, with a particular focus on pitch-perception deficit. Basic disorders in the six cases included epilepsy (cryptogenic localization-related epilepsy and benign childhood epilepsy) and glossopharyngeal neuralgia. Since 1993, in which we reported the first description of transient pitch-perception deficit associated with carbamazepine, a further 26 cases have been reported. However, this carbamazepine-induced transient pitch-perception deficit may be more frequent than previously suspected. Moreover, because auditory disturbance occurs at therapeutic serum levels of carbamazepine, patient awareness of reversible hearing impairment on initiating carbamazepine therapy is important.

Adult↗

Silicon modeling of pitch perception.

We have designed and tested an integrated circuit that models human pitch perception. The chip receives as input a time-varying voltage corresponding to sound pressure at the ear and produces as output a map of perceived pitch. The chip is a physiological model; subcircuits on the chip correspond to known and proposed structures in the auditory system. Chip output approximates human performance in response to a variety of classical pitch-perception stimuli. The 125,000-transistor chip computes all outputs in real time by using analog continuous-time processing.

Computer Simulation↗

Neural mechanism for binaural pitch perception via ghost stochastic resonance.

We present a physiologically plausible binaural mechanism for the perception of the pitch of complex sounds via ghost stochastic resonance. In this scheme, two neurons are driven by noise and a different periodic signal each (with frequencies f(1)=kf(0) and f(2)=(k+1)f(0), where k>1), and their outputs (plus noise) are applied synaptically to a third neuron. Our numerical results, using the Morris-Lecar neuron model with chemical synapses explicitly considered, show that intermediate noise levels enhance the response of the third neuron at frequencies close to f(0), as in the cases previously described of ghost resonance. For the case of an inharmonic combination of inputs (f(1)=kf(0)+Deltaf and f(2)=(k+1)f(0)+Deltaf) noise is also seen to enhance the rates of most probable spiking for the third neuron at a frequency f(r)=f(0)+[Deltaf(k+12)]. In addition, we show that similar resonances can be observed as a function of the synaptic time constant. The suggested ghost-resonance-based stochastic mechanism can thus arise either at the peripheral level or at a higher level of neural processing in the perception of pitch.

Biophysics↗

Pitch perception abnormality as a side effect of carbamazepine.

Carbamazepine (CBZ) is frequently used to treat patients with epilepsy, neuralgia, psychiatric diseases, etc. We prescribe it with care due to its side effects, mainly such as dizziness, sleepiness and cerebellar symptoms. But pitch perception abnormality is an uncommon side effect. We describe the case of a 12-year-old girl who exhibited half tone lowered pitch perception abnormality caused by CBZ. As CBZ acts as a central nervous system (CNS) inhibitor, we speculate that CBZ inhibits CNS and patients misperceive notes. We must prescribe CBZ with care to prevent pitch perception abnormalities.

Analgesics, Non-Narcotic↗

Intracerebral evoked potentials in pitch perception reveal a functional asymmetry of the human auditory cortex.

One acoustic feature that plays an important role in pitch perception is frequency. Studies on the processing of frequency in the human and animal brain have shown that the auditory cortex is tonotopically organized: low frequencies are represented laterally whereas high frequencies are represented medially. To date, the study of the functional organization of the human auditory cortex in the processing of frequency has been limited to the use of either scalp-recorded auditory evoked potentials (AEPs), which have relatively poor spatial resolving power, or functional imagery techniques, which have poor temporal resolving power. The present study uses intracerebrally recorded AEPs to explore this topic in the primary and secondary auditory cortices of both hemispheres of the human brain. Recordings were carried out in 45 adult patients with drug-resistant partial seizures. In the right hemisphere, clear spectrally organized tonotopic maps were observed with distinct separations between different frequency-processing regions. AEPs for high frequencies were recorded medially, whereas AEPs for low frequencies were recorded laterally. In the left hemisphere, however, this tonotopic organization was less evident, with different regions involved in the processing of a range of frequencies. The hemisphere-related difference in the processing of tonal frequency is discussed in relation to pitch perception.

Acoustic Stimulation↗

Neurophysiology and neuroanatomy of pitch perception: auditory cortex.

We present original results and review literature from the past fifty years that address the role of primate auditory cortex in the following perceptual capacities: (1) the ability to perceive small differences between the pitches of two successive tones; (2) the ability to perceive the sign (i.e., direction) of the pitch difference [higher (+) vs. lower (-)]; and (3) the ability to abstract pitch constancy across changes in stimulus acoustics. Cortical mechanisms mediating pitch perception are discussed with respect to (1) gross and microanatomical distribution; and (2) candidate neural coding schemes. Observations by us and others suggest that (1) frequency-selective neurons in primary auditory cortex (A1) and surrounding fields play a critical role in fine-grained pitch discrimination at the perceptual level; (2) cortical mechanisms that detect pitch differences are neuroanatomically dissociable from those mediating pitch direction discrimination; (3) cortical mechanisms mediating perception of the "missing fundamental frequency (F0)" are neuroanatomically dissociable from those mediating pitch perception when F0 is present; (4) frequency-selective neurons in both right and left A1 contribute to pitch change detection and pitch direction discrimination; (5) frequency-selective neurons in right A1 are necessary for normal pitch direction discrimination; (6) simple codes for pitch that are based on single- and multiunit firing rates of frequency-selective neurons face both a "hyperacuity problem" and a "pitch constancy problem"-that is, frequency discrimination thresholds for pitch change direction and pitch direction discrimination are much smaller than neural tuning curves predict, and firing rate patterns change dramatically under conditions in which pitch percepts remain invariant; (7) cochleotopic organization of frequency-selective neurons bears little if any relevance to perceptual acuity and pitch constancy; and (8) simple temporal codes for pitch capable of accounting for pitches higher than a few hundred hertz have not been found in the auditory cortex. The cortical code for pitch is therefore not likely to be a function of simple rate profiles or synchronous temporal patterns. Studies motivated by interest in the neurophysiology and neuroanatomy of music perception have helped correct longstanding misconceptions about the functional role of auditory cortex in frequency discrimination and pitch perception. Advancing knowledge about the neural coding of pitch is of fundamental importance to the future design of neurobionic therapies for hearing loss.

Acoustic Stimulation↗

Infants' pitch perception: inharmonic tonal complexes.

Two experiments assessed the effects of inharmonicity on 7- to 8-month-old infants' perception of the pitch of tonal complexes. A number of harmonic and inharmonic complexes were presented in a visually reinforced operant head turn procedure. In both experiments, infants demonstrated the ability to discriminate two harmonic complexes based on missing fundamental frequencies of 160 and 200 Hz. After learning this basic task, infants learned to discriminate inharmonic complexes, which were created by shifting the partials of the harmonic complexes upward by 30 Hz (experiment 1) or 20 Hz (experiment 2). Finally, three spectrally different inharmonic complexes represented each pitch, and infants attempted to categorize those complexes according to their pitches. In both experiments, infants successfully discriminated the pitches of the spectrally varying tonal complexes, but their performance deteriorated for the more strongly inharmonic complexes of experiment 1. These results suggest that, as for adults, the salience of pitch for inharmonic sounds decreases with increasing inharmonicity.

Female↗

Reversible pitch perception deficit caused by carbamazepine.

Carbamazepine (CBZ) is an antiepileptic drug frequently used to treat a variety of neurologic diseases or symptoms. In addition, the drug is used as a mood stabilizer in patients with affective or schizophrenic disorders. Among its adverse effects, auditory disturbance is described rarely. In this report, we describe a 25-year-old woman who noted falsely higher pitch perception after starting CBZ treatment for schizoaffective disorder. We also review the literature reporting CBZ-associated abnormal pitch perception.

Adult↗