A nonmusical paradigm for identifying absolute pitch possessors

The ability to identify and reproduce sounds of specific frequencies is remarkable and uncommon. The etiology and defining characteristics of this skill, absolute pitch (AP), have been very controversial. One theory suggests that AP requires a specific type of early musical training and that the ability to encode and remember tones depends on these learned musical associations. An alternate theory argues that AP may be strongly dependent on hereditary factors and relatively independent of musical experience. To date, it has been difficult to test these hypotheses because all previous paradigms for identifying AP have required subjects to employ knowledge of musical nomenclature. As such, these tests are insensitive to the possibility of discovering AP in either nonmusicians or musicians of non-Western training. Based on previous literature in pitch memory, a paradigm is presented that is intended to distinguish between AP possessors and nonpossessors independent of the subjects' musical experience. The efficacy of this method is then tested with 20 classically defined AP possessors and 22 nonpossessors. Data from these groups strongly support the validity of the paradigm. The use of a nonmusical paradigm to identify AP may facilitate research into many aspects of this phenomenon.     

Perceiving pitch absolutely: Comparing absolute and relative pitch possessors in a pitch memory task

Background  

The perceptual-cognitive mechanisms and neural correlates of Absolute Pitch (AP) are not fully understood. The aim of this fMRI study was to examine the neural network underlying AP using a pitch memory experiment and contrasting two groups of musicians with each other, those that have AP and those that do not.     

A psychophysical pitch function determined by absolute magnitude estimation and its relation to the musical pitch scale

A psychophysical pitch function, describing the relation of perceived magnitude of pitch to the frequency of a pure tone, was determined by absolute magnitude estimation. Pitch estimates were made by listeners with relative pitch and by absolute pitch possessors for 27 tones spanning a frequency range of 31.5-12,500 Hz in 1/3 octave steps. Results show that the pitch function, plotted in log-log coordinates, is steeper below 200 Hz than at higher frequencies. It is hypothesized that the pitch function's bend may reflect the diversity of neurophysiological mechanisms of pitch encoding in frequency ranges below and above 200 Hz. The variation of the function's slope implies that pitch distances between tones with the same frequency ratios are perceived as larger below 200 Hz than at higher frequencies. It is argued that this implication may apply only to a purely sensory concept of pitch distance and cannot be extended to the perception of musical intervals, a phenomenon governed by musical cognitive principles. The results also show that pitch functions obtained for listeners with relative and absolute pitch have a similar shape, which means that quantitative pitch relations determined for both groups of listeners do not differ appreciably along the frequency scale.     

Memory for pitch versus memory for loudness

The decays of pitch traces and loudness traces in short-term auditory memory were compared in forced-choice discrimination experiments. The two stimuli presented on each trial were separated by a variable delay (D); they consisted of pure tones, series of resolved harmonics, or series of unresolved harmonics mixed with lowpass noise. A roving procedure was employed in order to minimize the influence of context coding. During an initial phase of each experiment, frequency and intensity discrimination thresholds [P(C) = 0.80] were measured with an adaptive staircase method while D was fixed at 0.5 s. The corresponding physical differences (in cents or dB) were then constantly presented at four values of D: 0.5, 2, 5, and 10 s. In the case of intensity discrimination, performance (d') markedly decreased when D increased from 0.5 to 2 s, but was not further reduced when D was longer. In the case of frequency discrimination, the decline of performance as a function of D was significantly less abrupt. This divergence suggests that pitch and loudness are processed in separate modules of auditory memory.     

用千分表测量金属丝的弹性模量

基于用拉伸法测量金属丝的弹性模量,通过对千分表对传统测微装置进行替换,对实验过程进行了改进,简化了实验装置,节约了实验室空间,同时克服了原实验方法间接测量量多、实验时间长等缺点,使实验操作简单易行。     

Infant pitch perception: evidence for responding to pitch categories and the missing fundamental

While numerous studies on infant perception have demonstrated the infant's ability to discriminate sounds having different frequencies, little research has evaluated more sophisticated pitch perception abilities such as perceptual constancy and perception of the missing fundamental. In the present study 7-8-month-old infants demonstrated the ability to discriminate harmonic complexes from two pitch categories that differed in pitch by approximately 20% (e.g., 160 vs 200 Hz). Using a visually reinforced conditioned head-turning paradigm, a number of spectrally different tonal complexes that contained varying harmonic components but signaled the same two pitch categories were presented. After learning the basic pitch discrimination, the same infants learned to categorize spectrally different tonal complexes according to the pitches signaled by their fundamental frequencies. That is, the infants showed evidence of perceptual constancy for the pitch of harmonic complexes. Finally, infants heard tonal complexes that signaled the same pitch categories but for which the fundamental frequency was removed. Infants were still able to categorize the harmonic complexes according to their pitch categories. These results suggest that by 7 months of age infants show fairly sophisticated pitch perception abilities similar to those demonstrated by adults.     

A method for enlarging absolute phase unwrapping range by active phase setting

An active phase-setting method applied to a frequency-modulated grating is proposed for enlarging the absolute phase unwrapping range. It is found that the absolute phase unwrapping range is related to initial phase of grating. Therefore, the grating is optimized by presetting two different initial phases, which one is constant in frequency-modulation term and the other is related to the ratio of two frequency in linear phase-modulation term. By using absolute phase unwrapping algorithm, which is improved for suiting the new grating, absolute phase unwrapping range successfully is enlarged and achieves the theoretical range. The experimental results show the feasibility and validity of new method.     

A robust procedure for absolute phase measurement

A robust procedure for the measurement of absolute phase values with high accuracy is presented. This procedure is based on the derivation of a precision adapted sequence of grid orientations and the stepwise reconstruction of the continuous phase field without phase unwrapping. The determination of the angle sequence is oriented on the phase measuring accuracy and the known limits of the absolute phase. Similar results can be derived for the variation of the synthetic wavelength using contouring techniques where the object is illuminated with different wavelengths.     

A perceptual learning investigation of the pitch elicited by amplitude-modulated noise

Noise that is amplitude modulated at rates ranging from 40 to 850 Hz can elicit a sensation of pitch. Here, the processing of this temporally based pitch was investigated using a perceptual-learning paradigm. Nine listeners were trained (1 hour per day for 6-8 days) to discriminate a standard rate of sinusoidal amplitude modulation (SAM) from a faster rate in a single condition (150 Hz SAM rate, 5 kHz low-pass carrier). All trained listeners improved significantly on that condition. These trained listeners subsequently showed no more improvement than nine untrained controls on pure-tone and rippled-noise discrimination with the same pitch, and on SAM-rate discrimination with a 30 Hz rate, although they did show some improvement with a 300 Hz rate. In addition, most trained, but not control, listeners were worse at detecting SAM at 150 Hz after, compared to before training. These results indicate that listeners can learn to improve their ability to discriminate SAM rate with multiple-hour training and that the mechanism that is modified by learning encodes (1) the pitch of SAM noise but not that of pure tones and rippled noise, (2) different SAM rates separately, and (3) differences in SAM rate more effectively than cues for SAM detection.     

A memory device sustained by noise

We propose a memory device consisting of a ring of two bistable coupled oscillators. We show that this system is capable of storing a single bit and its performance improves with noise, in agreement with previous experimental results obtained with discrete bistable electronic circuits. The stored bit can be retrieved asynchronously and, after a certain synchronization time, the probability of error does not depend on the interrogated oscillator. Memory persistence is shown to be maximized for the same noise range that both minimizes the probability of error and ensures synchronization.     

Seeing pitch: visual information for lexical tones of Mandarin-Chinese

Mandarin perceivers were tested in visual lexical-tone identification before and after learning. Baseline performance was only slightly above chance, although there appeared to be some visual information in the speakers' neck and head movements. When participants were taught to use this visible information in two experiments, visual tone identification improved significantly. There appears to be a relationship between the production of lexical tones and the visible movements of the neck, head, and mouth, and this information can be effectively used after a short training session.     

Perceived pitch of whispered vowels-relationship with formant frequencies: A preliminary study

To clarify the role of formant frequency in the perception of pitch in whispering, we conducted a preliminary experiment to determine (1.) whether speakers change their pitch during whispering; (2.) whether listeners can perceive differences in pitch; and (3.) what the acoustical features are when speakers change their pitch. The listening test of whispered Japanese speech demonstrates that one can determine the perceived pitch of vowel /a/ as ordinary, high, or low. Acoustical analysis revealed that the perception of pitch corresponds to some formant frequencies. Further data with synthesized whispered voice are necessary to confirm the importance of the formant frequencies in detail for perceived pitch of whispered vowels.     

一种光学频率梳绝对测距的新方法

采用光学频率梳的高精度绝对距离测量技术在航空航天、科学研究和工业生产等领域都发挥着重要作用.提出一种利用光学频率梳技术,通过检测光强实现绝对距离测量的新方法,研究了光学频率梳发出脉冲的时间相干性,分析了光强与被测距离之间的关系、干涉条纹峰值点位置与被测距离之间的关系.建立了基于Michelson干涉原理的测距系统,通过测量光强信息得到被测距离.以高精度纳米位移平台的位移量作为长度基准进行了绝对测距实验,在每个被测距离点都重复进行了10次实验,将10次实验测得的光强值取平均后用于距离的计算.实验结果表明,该方法可以实现绝对距离测量,在10μm测量范围内,最大误差为47 nm.因此,该方法可以应用于大尺寸高精度的绝对距离测量.     

A comparison of absolute cross sections for electro- and photo-induced reactions

Absolute cross sections for electron and positron induced reactions on¹²C,⁶³Cu and¹⁰⁷Ag are compared with cross sections for the corresponding photo-induced reactions in order to test DWBA calculations of the virtual photon spectra. A good agreement is found between the experimental cross sections for the electrodisintegration and those calculated with DWBA spectra and photonuclear cross sections.     

A method for the absolute measurement of anisotropic surface free energies

Using the vector method of Cahn and Hoffman, equations are derived that relate the anisotropic surface free energy to the shapes of grain-boundary grooves at the solid-vapor, solidsolvent, solid-solid, or solid-melt interface in either a gravitational field or a temperature gradient. The components of the vector function ξ at any point on the surface of the groove are given in terms of distances and areas directly measurable on micrographs. The surface free energy is the component of ξ along the surface normal. The experimental methods now in use for measuring absolute surface energy in the isotropic case, can be employed without modification to yield data for the evaluation of anisotropic surface free energy and surface torques. Procedures for using the symmetry properties of crystals to remove the indeterminacy and reduce the amount of data gathering for anisotropic crystals are developed.     

Transferability of dipole moment derivatives: A general method for the calculation of absolute rotational contributions

A general method for the calculation of absolute rotational corrections for the dipole moment derivatives is given based on the definition of pure geometrical distortions. The method is generally valid and allows the rotational contributions to be calculated for all modes of any molecule. The relation between absolute and relative corrections is discussed and the method is demonstrated by calculating the rotational corrections for a few asymmetrical molecules.     

MeCAT peptide labeling for the absolute quantification of proteins by 2D-LC-ICP-MS

Metal-Coded Affinity Tags (MeCAT) reagents were devised for the absolute quantification of labeled proteins and peptides using inductively coupled plasma mass spectrometry (ICP-MS). After the recent publication of quantification approaches for digested proteins, this work presents a multidimensional strategy for the application of MeCAT to samples which require higher chromatographic resolution. Two-dimensional separations based on strong cation exchange (SCX) and reversed-phase (RP) chromatography, were used for the quantification of lysozyme, bovine serum albumin and transferrin after tryptic digestion. The elution protocols were optimized to improve the resolution of the MeCAT-labeled peptides which led to faster elutions in SCX and longer retention times in RP compared with unlabeled peptides. The optimized method provided enough resolution for the samples analyzed. Peptides losses during the whole procedure were studied. Although recoveries of greater than 90% were found in the RP dimension, important global losses in the two-dimensional offline approach forced us to use specific internal standards, in this case MeCAT-labeled standard peptides. External calibration and label-specific isotope dilution analysis (IDA) were tested and compared as possible quantification techniques. While both techniques showed accurate and precise determinations, the label-specific IDA technique resulted in more straightforward measurements and more affordable external calibrations. Finally, simultaneous quantification of three different samples labeled with different lanthanides was successfully performed demonstrating the potential of MeCAT combined with ICP-MS for multiplexing. Electrospray ionization mass spectrometry techniques provided the structural information needed for the identification of the labeled species.