The octave illusion revisited: Suppression or fusion between ears?

The octave illusion occurs when each ear receives a sequence of tones alternating by 1 octave but with the high and low tones in different ears. Most listeners perceive these stimuli as a high pitch in one ear alternating with a low pitch in the other ear. D. Deutsch and P. L. Roll (1976) interpreted this phenomenon as evidence for a what-where division of auditory processing caused by sequential interactions between the tones. They argued that the pitch follows the frequency presented to the dominant ear but is lateralized toward the higher frequency component. This model was examined in 4 experiments. Results indicate that the perceived pitch approximates the fundamental frequency and that the illusion does not depend on sequential interactions. The octave illusion may arise from an interaction between dichotic fusion and binaural diplacusis rather than from suppression as proposed by Deutsch. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tone sequences with conflicting fundamental pitch and timbre changes are heard differently by musicians and nonmusicians.

An Auditory Ambiguity Test (AAT) was taken twice by nonmusicians, musical amateurs, and professional musicians. The AAT comprised different tone pairs, presented in both within-pair orders, in which overtone spectra rising in pitch were associated with missing fundamental frequencies (F0) falling in pitch, and vice versa. The F0 interval ranged from 2 to 9 semitones. The participants were instructed to decide whether the perceived pitch went up or down; no information was provided on the ambiguity of the stimuli. The majority of professionals classified the pitch changes according to F0, even at the smallest interval. By contrast, most nonmusicians classified according to the overtone spectra, except in the case of the largest interval. Amateurs ranged in between. A plausible explanation for the systematic group differences is that musical practice systematically shifted the perceptual focus from spectral toward missing-F0 pitch, although alternative explanations such as different genetic dispositions of musicians and nonmusicians cannot be ruled out. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adaptation to auditory streaming of frequency-modulated tones.

Studied the time course of perceptual adaptation to auditory system segregation in 5 experiments in which 5 male and female Ss listened to a tone that was frequency modulated by a square wave so that it consisted of 2 repeatedly alternating tones of different frequency. This initially sounded like a single tone jumping up and down in pitch (temporal coherence), but perceptual adaptation changed the percept into a high-pitched interrupted tone plus a concurrent low-pitched interrupted tone (fission or stream segregation). It was found that the probability of hearing temporal coherence decreased steadily over time as adaptation increased. Probability of temporal coherence fell off linearly as a function of log modulation rate (over the range from about 2–20 cycles/second) and of log tonal interval (from about a semitone to an octave). Adapting to one center audiofrequency and testing at another showed that the adaptation was frequency tuned with a bandwidth comparable to 1 critical band. Adapting one ear and testing the other showed no interaural transfer of the adaptation. Results show that adaptation to a frequency-modulated tone leads to a progressive change from coherence to segregation. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Higher order pattern structure influences auditory representational momentum.

Representational momentum refers to the phenomenon that observers tend to incorrectly remember an event undergoing real or implied motion as shifted beyond its actual final position. This has been demonstrated in both visual and auditory domains. In 5 pitch discrimination experiments, listeners heard tone sequences that implied either linear, periodic, or null motions in pitch space. Their task was to judge whether the pitch of a probe tone following each sequence was the same or different from the final sequence tone. Results suggested that listeners made errors consistent with extrapolation of coherent pitch patterns (linear, periodic) but not with incoherent (null) ones. Hypotheses associated with internalized physical principles and pattern-based expectations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Doppler illusion: The influence of dynamic intensity change on perceived pitch.

Four studies illustrate a new auditory illusion associated with the Doppler effect and demonstrate a new influence of dynamic intensity change on perceived pitch. Experiment 1 confirmed the existence of a popular belief that the pitch of a moving sound source rises as the source approaches. Because there is no corresponding rise in frequency, the authors refer to the perceived pitch rise as the Doppler illusion. Experiment 2 confirmed that the effect occurs perceptually, so the belief in a "naive principle" of physics has a perceptual basis. Experiment 3 confirmed the effect does not occur under matched static conditions. Experiment 4 showed that the influence of dynamic intensity change on perceived pitch occurs outside the realm of Doppler stimuli. The findings support a dynamic dimensional interaction of pitch and loudness, with marked differences in the perception of pitch and loudness under static and dynamic conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceiving the Intensity of Light.

The relationship between luminance (i.e., the photometric intensity of light) and its perception (i.e., sensations of lightness or brightness) has long been a puzzle. In addition to the mystery of why these perceptual qualities do not scale with luminance in any simple way, "illusions" such as simultaneous brightness contrast, Mach bands, Craik-O'Brien-Cornsweet edge effects, and the Chubb-Sperling-Solomon illusion have all generated much interest but no generally accepted explanation. The authors review evidence that the full range of this perceptual phenomenology can be rationalized in terms of an empirical theory of vision. The implication of these observations is that perceptions of lightness and brightness are generated according to the probability distributions of the possible sources of luminance values in stimuli that are inevitably ambiguous. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spectral envelope and context effects in the tritone paradox

In previous studies of the 'tritone paradox' Deutsch has suggested that, when listeners are presented with pairs of octave-complex tones that are equal in average log frequency but differ in chroma by 6 semitones (a tritone), they perceive the direction of the chroma difference according to an individual pitch-class template. However, it has also been found that the perceived direction changes for many listeners when the spectral envelope of the tones is shifted along the frequency axis. Reanalysis of these data indicates a strong tendency to perceive the pitch class corresponding to the frequency on which the spectral envelope is centered as subjectively lowest. In experiment 1 this spectral-envelope effect was replicated with tone pairs presented in isolation, at the rate of one a day, which rules out artifacts of test format. In experiment 2, involving another context-free format, envelope center frequency was varied over a wide range and it was shown that some individuals are totally envelope dependent, whereas others rely more on pitch class, and yet others show mixed patterns. Experiment 3 demonstrated that listeners' judgments of tritone pairs can be swayed easily by preceding context. Finally, experiment 4 showed that strong envelope effects are also obtained with Deutsch's own tritone test (issued on CD). The subjective relative pitch height of octave-complex tones thus depends on several competing factors, only one of which is pitch class.     

Causality and cross-modal integration.

Schutz and Lipscomb (2007) reported an audiovisual illusion in which the length of the gesture used to produce a sound altered the perception of that sound’s duration. This contradicts the widely accepted claim that the auditory system generally dominates temporal tasks because of its superior temporal acuity. Here, in the first of 4 experiments, we show that impact gestures influence duration ratings of percussive but not sustained sounds. In the 2nd, we show that the illusion is present even if the percussive sound occurs up to 700 ms after the visible impact, but disappears if the percussive sound precedes the visible impact. In the 3rd experiment, we show that only the motion after the visible impact influences perceived tone duration. The 4th experiment (replacing the impact gestures with the written text long and short) suggests that the phenomenon is not due to response bias. Given that visual influence in this paradigm is dependent on the presence of an ecologically plausible audiovisual relationship, we conclude that cross-modal causality plays a key role in governing the integration of sensory information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pitch perception in chinchillas (Chinchilla laniger): Stimulus generalization using rippled noise.

Rippled noises evoke the perception of pitch in human listeners. Infinitely iterated rippled noise (IIRN) is generated when wideband noise (WBN) is delayed, attenuated, and added to the original WBN through either a positive (+) or a negative (-) feedback loop. The pitch of IIRN[+] is matched to the reciprocal of the delay, whereas the pitch of IIRN[-] for the same delay is an octave lower. Chinchillas (Chinchilla laniger) were trained to discriminate IIRN[+] with a 4-ms delay from IIRN[+] with a 2-ms delay and then tested in a stimulus generalization paradigm with IIRN[+] at delays between 2 and 4 ms. Systematic gradients in behavioral response occurred along the dimension of delay, suggesting that a perceptual dimension corresponding to pitch exists for IIRN[+]. Behavioral responses to IIRN[-] test stimuli were more variable among chinchillas, suggesting that IIRN[-] did not evoke similar pitches relative to IIRN[+]. Systematic gradients in behavioral response were observed when IIRN[-] test stimuli were presented in the context of other IIRN[-] stimuli. Thus, other perceptual cues such as timbre may dominate the pitch cues when IIRN[-] test stimuli are presented in the context of IIRN[+] stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Size illusion, distance illusion, and terrestrial passage: Comment on Reed.

Comments on C. F. Reed's (see record 1985-29807-001) terrestrial-passage theory, in which it is assumed that the moon's failure to increase in visual subtense while elevating is accounted for strictly by perceptual distancing. This allows a formal account of the moon distance illusion, but at the expense of a compelling explanation of the moon size illusion. In order to explain the distance illusion, Reed also assumes that all objects, regardless of their perceived altitude, are perceived to start from a common point at the horizon. Several alternative applications of Reed's terrestrial-passage foundation to the actual illusions are suggested. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Perceptual Integration of Auditory Stimulus Edges: An Illusory Short Tone in Stimulus Patterns Consisting of Two Partly Overlapping Glides.

Two partly overlapping frequency glides can be perceived as consisting of a long pitch trajectory accompanied by a short tone in the temporal middle. It was found that the appearance of this middle tone could not be related to peripheral processes concerned with spectral splatter or combination tones that could have emerged during the overlap of the glides. Furthermore, it was found that the middle tone was perceived even when components of the 2 glides were separated by more than an equivalent rectangular bandwidth at any time during the overlap. The appearance of the middle tone indicates that auditory events can result from the perceptual integration of component parts-that is, stimulus edges-of acoustically different sounds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral studies of sound localization in the cat

Using the magnetic search coil technique to measure eye and ear movements, we trained cats by operant conditioning to look in the direction of light and sound sources with their heads fixed. Cats were able to localize noise bursts, single clicks, or click trains presented from sources located on the horizontal and vertical meridians within their oculomotor range. Saccades to auditory targets were less accurate and more variable than saccades to visual targets at the same spatial positions. Localization accuracy of single clicks was diminished compared with the long-duration stimuli presented from the same sources. Control experiments with novel auditory targets, never associated with visual targets, demonstrated that the cats localized the sound sources using acoustic cues and not from memory. The role of spectral features imposed by the pinna for vertical sound localization was shown by the breakdown in localization of narrow-band (one-sixth of an octave) noise bursts presented from sources along the midsagittal plane. In addition, we show that cats experience summing localization, an illusion associated with the precedence effect. Pairs of clicks presented from speakers at (+/-18 degrees,0 degrees ) with interclick delays of +/-300 microsec were perceived by the cat as originating from phantom sources extending from the midline to approximately +/-10 degrees.     

Tinnitus and Hearing Loss in Hamsters (Mesocricetus auratus) Exposed to Loud Sound.

Hamsters were trained to go left and right to sounds on their left and right sides, respectively. Silent trials were occasionally given in which no sound was presented. Hamsters exposed to a loud 2- or 10-kHz tone in 1 ear often shifted their responding on the silent trials to the side of the exposed ear, suggesting that they perceived a sound in that ear (i.e., tinnitus). The degree of tinnitus was related to the degree of the accompanying hearing loss (estimated by the auditory brainstem response). However, a conductive hearing loss (plugging 1 ear) did not cause a hamster to test positive for tinnitus. Tinnitus could be demonstrated within minutes following tone exposure, indicating an immediate onset, as occurs in humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual interactions between musical pitch and timbre.

Three experiments examined perceptual interactions between musical pitch and timbre. Exp 1, through the use of the Garner classification tasks, found that pitch and timbre of isolated tones interact. Classification times showed interference from uncorrelated variation in the irrelevant attribute and facilitation from correlated variation; the effects were symmetrical. Exps 2 and 3 examined how musical pitch and timbre function in longer sequences. In recognition memory tasks, a target tone always appeared in a fixed position in the sequences, and listeners were instructed to attend to either its pitch or its timbre. For successive tones, no interactions between timbre and pitch were found. That is, changing the pitches of context tones did not affect timbre recognition, and vice versa. The tendency to perceive pitch in relation to other context pitches was strong and unaffected by whether timbre was constant or varying. In contrast, the relative perception of timbre was weak and was found only when pitch was constant. These results suggest that timbre is perceived more in absolute than in relative terms. Perceptual implications for creating patterns in music with timbre variations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Consumer behavior and perceived decision freedom: A reexamination.

D. J. Reibstein et al (see record 1975-28533-001) found that for 2- and 4-alternative choice sets, perceived decision freedom was positively related to amount of soft drink consumed but was not related to postchoice attitude change. The present study with 72 undergraduates attempted to replicate these findings while controlling for a quantity effect and similarity of preference toward alternatives in the respective choice sets. Results indicate that perceived decision freedom is not linearly related to soft drink consumption. Furthermore, some support for a positive relationship between perceived decision freedom and postchoice attitude change was found. A possible explanation of the conflict between these studies is discussed. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory temporal order perception in younger and older adults

This investigation examined the abilities of younger and older listeners to discriminate and identify temporal order of sounds presented in tonal sequences. It was hypothesized that older listeners would exhibit greater difficulty than younger listeners on both temporal processing tasks, particularly for complex stimulus patterns. It was also anticipated that tone order discrimination would be easier than tone order identification for all listeners. Listeners were younger and older adults with either normal hearing or mild-to-moderate sensorineural hearing losses. Stimuli were temporally contiguous three-tone sequences within a 1/3 octave frequency range centered at 4000 Hz. For the discrimination task, listeners discerned differences between standard and comparison stimulus sequences that varied in tonal temporal order. For the identification task, listeners identified tone order of a single sequence using labels of relative pitch. Older listeners performed more poorly than younger listeners on the discrimination task for the more complex pitch patterns and on the identification task for faster stimulus presentation rates. The results also showed that order discrimination is easier than order identification for all listeners. The effects of hearing loss on the ordering tasks were minimal.     

Interval and contour in serial pitch perception by a passerine bird, the European starling (Sturnus vulgaris).

Examined the capacity of starlings to perceive and process pitch information in serial acoustic patterns in 7 experiments. Exps I–III studied the discrimination of sequences of tones that rose or fell in pitch when the interval size between successive pitches changed relative to a standard baseline interval. The rising/falling discrimination maintained itself—the birds showed perceptual constancy—when intervals were halved, varied randomly in size, or changed to a continuous frequency sweep. Exps IV–VI examined discrimination performance when pitch contour (i.e., up and down pitch relation from tone to tone) was changed from the baseline patterns. Ss responded preferentially to early rising/falling pitch information on a pitch sequence; they ignored later relative pitch information even when it contradicted early information. However, they could delay pitch processing if initial tones lacked up or down pitch cues. Exp VII was an exploration of the birds' consistent predilection to use absolute frequency value, as opposed to relative pitch, as a discriminative cue in pitch pattern perception. Results suggest a comparison between the cognitive ability of humans and that of animals to process serial acoustic information. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition priming in music.

The authors explore priming effects of pitch repetition in music in 3 experiments. Musically untrained participants heard a short melody and sang the last pitch of the melody as quickly as possible. Each experiment manipulated (a) whether or not the tone to be sung (target) was heard earlier in the melody (primed) and (b) the prime-target distance (measured in events). Experiment 1 used variable-length melodies, whereas Experiments 2 and 3 used fixed-length melodies. Experiment 3 changed the timbre of the target tone. In all experiments, fast-responding participants produced repeated tones faster than nonrepeated tones, and this repetition benefit decreased as prime-target distances increased. All participants produced expected tonic endings faster than less expected nontonic endings. Repetition and tonal priming effects are compared with harmonic priming effects in music and with repetition priming effects in language. (PsycINFO Database Record (c) 2011 APA, all rights reserved)