Why is the perceptual octave stretched? An account based on mismatched time constants within the auditory brainstem

This paper suggests an explanation for listener’s greater tolerance to positive than negative mistuning of the higher tone within an octave pair. It hypothesizes a neu- ral circuit tuned to cancel the lower tone, that also cancels the higher tone if that tone is in tune. Imperfect cancellation is the cue to mistuning of the octave. The circuit involves two pathways, one delayed with respect to the other, that feed a coincidence-counting neuron via excitatory and inhibitory synapses. A mismatch between the time constants of these two synapses results in an asymmetry in sen- sitivity to mismatch. Specifically, if the time constant of the delayed pathway is greater than that of the direct pathway, there is a greater tolerance to positive than to negative mistuning, which can lead to a perceptual“stretch” of the octave. The model is applicable to both harmonic and – with qualification – melodic oc- taves. The paper describes the model and reviews the evidence from auditory psychophysics and physiology in favor – or against – it.

The Translation of English Comment Clauses in Shakespeare's Othello into Arabic

Comment clauses (or parentheticals) are a type of clauses which are syntactically disconnected from the clause to which they are attached and which are syntactically incomplete (lack complementation).They show a reflection of the main clause,commentary or assessment on the main clause and hence show more spatial flexibility, lower tone, and semantic independence . The present study focuses on comment clauses as pragmatic markers and the implicit meaning carried by these clauses .The problem is that most translators overlook this type of clauses because of their unawareness of the implied meaning carried by such clauses,especially when they translate them.It is hypothesized that the interpretation of comment clauses is situational.To prove this hypothesis, ten texts have been arbitrarily selected from Shakespeare's Othello translated into Arabic by four well- known translators, namely: Jabra Ibrahim Jabra Muhammed Mustafa Badawi, Ghazi Gamal and Khalil Mutran. The study concludes that the interpretation of comment clauses depends largely on the situation in which they are used.The study also discloses that the failure in translating such clauses is due to the unawareness of the implicit meaning that the comment clauses carry (whether in spoken or written). Finally,the study recommends that translators should carefully deal with comment clauses wherever they come across them,for such a type of clauses could form a slippery area.

Automatic Tuning of High Piano Tones

Piano tuning is known to be difficult because the stiffness of piano strings causes the tones produced to be inharmonic. Aural tuning is time consuming and requires the help of a professional. This motivates the question of whether this process can be automated. Attempts at automatic tuning are usually assessed by comparing the Railsback curve of the results with the curve of a professional tuner. In this paper we determine a simple and reliable rule for tuning the high tones of a piano with the help of a listening test. This rule consists of matching the two tones in an octave interval so that the first partial frequency of the upper tone becomes exactly the same as the second partial frequency of the lower tone. This rule was rated best among four tuning rules that were compared in the test. The results found are explained using a beat-based analysis, and are consistent with some previous studies. They are also tested against the existing method of using Railsback curves, and it is shown that comparison using Railsback curves is an unreliable method of assessing different tunings. The findings from this paper can be used to create a complete automatic tuner that could make the process of piano tuning quick and inexpensive.

Tone Profiles of Isolated Musical Chords: Psychoacoustic Versus Cognitive Models

We investigated perception of virtual pitches at missing fundamentals (MFs) in musical chords of three chromas (simultaneous trichords). Tone profiles for major, minor, diminished, augmented, suspended, and four other trichords of octave-complex tones were determined. In Experiment 1, 40 musicians rated how well a tone went with a preceding chord; in Experiment 2, whether the tone was in the chord. Mean ratings for nine non-chord tones were compared with predictions of four models: MFs, diatonicity, 5th-interval relations, and tones that complete familiar tetrachords (e.g., 7th chords). Profiles were accounted for by all four models in Experiment 1, and two (MFs, 5th relations) in Experiment 2. Overall, effect size was largest for MFs. In Experiment 3, listeners heard a chord and chose a matching tone from 12 possibilities. Profile peaks were predicted by pitch models (usually, the lower tone of a perfect 5th). Participants who more likely attended to MFs in isolated harmonic complex tones (fundamental listeners) were not more sensitive to MFs in chords, suggesting their responses instead depended on statistical properties of familiar music. We propose a speculative, psychohistoric explanation: MFs influenced the historical development of musical structure, which in turn influenced the perception of enculturated modern listeners.

How the Blind Hear Colour

Crossmodal correspondences between seemingly independent sensory modalities are often observed in normal participants. For instance, colours commonly map consistently onto pure tones. In this study, we investigated colour-tone mapping in both normal trichromats and in people with congenital blindness. Participants were asked to match tones of differing pitch to named colours. In both cases, the tones selected varied consistently with the colour. The blind responses were similar to those of the trichromats, except in the case of red and green; the blind did not differentiate these colours, whereas the trichromats associated red with a higher tone and green with a lower tone. Otherwise, the results are consistent with a well-established association between pitch and lightness, with lighter colours associated with higher tones, and darker colours with lower tones. Because the blind never had any sensory experience of colour, their matching of colour to pitch is most likely based on semantic understanding.

A Valid Demonstration of the Missing Fundamental Illusion

When 2 tones occur together, a 3rd tone, with a pitch corresponding to the difference in their frequencies, is sometimes heard. This tone is referred to as the missing fundamental because the lister***er perceives this lower tone (fundamental) although there is no actual vibration at this frequency. This effect is discussed in many sensation and perception textbooks. The nonlinearities of recording arid playback equipment may actually restore the supposedly missing fundamental in recorded demonstrations of this effect. In this article, we describe an inexpensive and valid demonstration of the missing fundamental, using a British police whistle.