Behavioral responses to harmonic complex tones with missing fundamental frequencies by chinchillas in the presence of low‐pass masking noise.

2009 ◽  
Vol 125 (4) ◽  
pp. 2721-2721
Author(s):  
William P. Shofner
Keyword(s):  
Behavioral Responses ◽  
Harmonic Complex ◽  
Fundamental Frequencies ◽  
Complex Tones ◽  
Low Pass ◽  
Masking Noise ◽  
Missing Fundamental

Roughness of Two Simultaneous Harmonic Complex Tones On Just-Tempered and Equal-Tempered Scales

2017 ◽  
Vol 35 (2) ◽  
pp. 127-143
Author(s):  
Václav Vencovský ◽  
František Rund
Keyword(s):  
Fundamental Frequency ◽  
Basilar Membrane ◽  
Auditory Periphery ◽  
Harmonic Complex ◽  
Phase Fluctuations ◽  
Fundamental Frequencies ◽  
Spectral Components ◽  
Complex Tones ◽  
Si Model ◽  
Possible Cause

This study is focused on the perceived roughness of two simultaneous harmonic complex tones with ratios between their fundamental frequencies set to create intervals on just-tempered (JT) and equal-tempered (ET) scales. According to roughness theories, ET intervals should produce more roughness. However, previous studies have shown the opposite for intervals in which the lower fundamental frequency of the complex was equal to 261.6 Hz. The aim of this study is to verify and explain these results by using intervals composed of complexes whose spectral components were generated with either a sine starting phase or with a random starting phase. Results of the current study showed the same phenomenon as previous studies. To examine whether the explanation of the phenomenon lies in the function of the peripheral ear, three roughness models based upon this function were used: the Daniel and Weber (1997) model, the synchronization index (SI) model, and the model based on a hydrodynamic cochlear model. For most of the corresponding JT and ET intervals, only the Daniel and Weber (1997) model predicted less roughness in the ET intervals. In addition to this, the intervals were analyzed by a model simulating the auditory periphery. The results showed that a possible cause for the roughness differences may be in the frequencies of fluctuations of the signal in the peripheral ear. For JT intervals the fluctuations in the adjacent places on the simulated basilar membrane had either the same frequency or integer multiples of that frequency and were synchronized. Since a previous study showed that synchronized fluctuations in adjacent auditory filters lead to higher roughness than out of phase fluctuations (Terhardt, 1974), this may cause more roughness across JT and ET intervals.

Pitch Perception of Medium-Rank Harmonic Complex Tones Based on Temporal Analysis

2013 ◽  
Vol 860-863 ◽  
pp. 2924-2928
Author(s):  
Jian Wang ◽  
Tian Guan ◽  
Da Tian Ye
Keyword(s):  
Temporal Analysis ◽  
Peak Height ◽  
Frequency Region ◽  
Complex Tone ◽  
Temporal Fine Structure ◽  
Harmonic Complex ◽  
Structure Information ◽  
Fundamental Frequencies ◽  
Complex Tones ◽  
Phase Combination

Fundamental frequency difference limens were measured for a target harmonic complex tone (HCT) in the absence and presence of a masker HCT, which were filtered into the same bandpass frequency region and were gated on and off synchronously. There were three kinds of nominal fundamental frequencies (F0s) for target (200, 400, and 800 Hz), five kinds of F0 separations between target and masker (0, ±3, and ±6 semitones), and four kinds of phase combinations. Results found significant effects of nominal F0, phase combination, and F0 separation between target and masker. Analysis based on temporal profile proved that the significant effect of nominal F0 could be explained by peak height of target, and that the significant effects of F0 separation and phase combination could be explained by the ratio of temporal peak heights between target and masker. Thus it is suggested that F0 discrimination of medium-rank harmonics probably depends on the use of temporal fine structure information.

scholarly journals Different Modes of Pitch Perception and Learning-Induced Neuronal Plasticity of the Human Auditory Cortex

2002 ◽  
Vol 9 (3) ◽  
pp. 161-175 ◽  
Author(s):  
Michael Schulte ◽  
Arne Knief ◽  
Annemarie Seither-Preisler ◽  
Christo Pantev
Keyword(s):  
Auditory Cortex ◽  
Neuronal Plasticity ◽  
Pitch Perception ◽  
Gamma Band ◽  
Base Line ◽  
Band Frequency ◽  
Harmonic Complex ◽  
Fundamental Frequencies ◽  
Complex Tones ◽  
Virtual Pitch

We designed a melody perception experiment involving eight harmonic complex tones of missing fundamental frequencies (hidden auditory object) to study the short-term neuronal plasticity of the auditory cortex. In this experiment, the fundamental frequencies of the complex tones followed the beginning of the virtual melody of the tune “Frère Jacques”. The harmonics of the complex tones were chosen so that the spectral melody had an inverse contour when compared with the virtual one. Evoked magnetic fields were recorded contralaterally to the ear of stimulation from both hemispheres. After a base line measurement, the subjects were exposed repeatedly to the experimental stimuli for 1 hour a day. All subjects reported a sudden change in the perceived melody, indicating possible reorganization of the cortical processes involved in the virtual pitch formation. After this switch in perception, a second measurement was performed. Cortical sources of the evoked gamma-band activity were significantly stronger and located more medially after a switch in perception. Independent Component Analysis revealed enhanced synchronization in the gamma-band frequency range. Comparing the gamma-band activation of both hemispheres, no laterality effects were observed. The results indicate that the primary auditory cortices are involved in the process of virtual pitch perception and that their function is modifiable by laboratory manipulation.

scholarly journals Pitch of Complex Tones: Rate-Place and Interspike Interval Representations in the Auditory Nerve

2005 ◽  
Vol 94 (1) ◽  
pp. 347-362 ◽  
Author(s):  
Leonardo Cedolin ◽  
Bertrand Delgutte
Keyword(s):  
Auditory Nerve ◽  
Interspike Interval ◽  
Discharge Rate ◽  
Phase Locking ◽  
Entire Sample ◽  
Harmonic Complex ◽  
Upper Limit ◽  
Complex Tones ◽  
Interval Representations ◽  
Missing Fundamental

Harmonic complex tones elicit a pitch sensation at their fundamental frequency (F0), even when their spectrum contains no energy at F0, a phenomenon known as “pitch of the missing fundamental.” The strength of this pitch percept depends upon the degree to which individual harmonics are spaced sufficiently apart to be “resolved” by the mechanical frequency analysis in the cochlea. We investigated the resolvability of harmonics of missing-fundamental complex tones in the auditory nerve (AN) of anesthetized cats at low and moderate stimulus levels and compared the effectiveness of two representations of pitch over a much wider range of F0s (110–3,520 Hz) than in previous studies. We found that individual harmonics are increasingly well resolved in rate responses of AN fibers as the characteristic frequency (CF) increases. We obtained rate-based estimates of pitch dependent upon harmonic resolvability by matching harmonic templates to profiles of average discharge rate against CF. These estimates were most accurate for F0s above 400–500 Hz, where harmonics were sufficiently resolved. We also derived pitch estimates from all-order interspike-interval distributions, pooled over our entire sample of fibers. Such interval-based pitch estimates, which are dependent on phase-locking to the harmonics, were accurate for F0s below 1,300 Hz, consistent with the upper limit of the pitch of the missing fundamental in humans. The two pitch representations are complementary with respect to the F0 range over which they are effective; however, neither is entirely satisfactory in accounting for human psychophysical data.

Rabbits use both spectral and temporal cues to discriminate the fundamental frequency of harmonic complexes with missing fundamentals

2021 ◽  
Author(s):  
Joseph D Wagner ◽  
Alice Gelman ◽  
Kenneth E. Hancock ◽  
Yoojin Chung ◽  
Bertrand Delgutte
Keyword(s):  
Fundamental Frequency ◽  
Human Performance ◽  
Spectral Composition ◽  
Pitch Perception ◽  
Wide Frequency Range ◽  
Spatial Gradient ◽  
Harmonic Complex ◽  
Complex Tones ◽  
Behavioral Paradigm ◽  
Animal Vocalizations

The pitch of harmonic complex tones (HCT) common in speech, music and animal vocalizations plays a key role in the perceptual organization of sound. Unraveling the neural mechanisms of pitch perception requires animal models but little is known about complex pitch perception by animals, and some species appear to use different pitch mechanisms than humans. Here, we tested rabbits' ability to discriminate the fundamental frequency (F0) of HCTs with missing fundamentals using a behavioral paradigm inspired by foraging behavior in which rabbits learned to harness a spatial gradient in F0 to find the location of a virtual target within a room for a food reward. Rabbits were initially trained to discriminate HCTs with F0s in the range 400-800 Hz and with harmonics covering a wide frequency range (800-16,000 Hz), and then tested with stimuli differing either in spectral composition to test the role of harmonic resolvability (Experiment 1), or in F0 range (Experiment 2), or both F0 and spectral content (Experiment 3). Together, these experiments show that rabbits can discriminate HCTs over a wide F0 range (200-1600 Hz) encompassing the range of conspecific vocalizations, and can use either the spectral pattern of harmonics resolved by the cochlea for higher F0s or temporal envelope cues resulting from interaction between unresolved harmonics for lower F0s. The qualitative similarity of these results to human performance supports using rabbits as an animal model for studies of pitch mechanisms providing species differences in cochlear frequency selectivity and F0 range of vocalizations are taken into account.

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