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At least 937 records · Page 52Linked to original sources
PubMed2000

The irrelevant sound effect: does speech play a special role?

Memory for order is markedly impaired by the presence of irrelevant sound, even though participants are instructed to ignore the sound. Although a great deal of research has disclosed some features of the task and of the sound that augment or reduce the degree of interference, one important issue of the irrelevant sound effect not yet resolved is whether speech has a special status. This study revealed, within a design of adequate power, that the same physical stimulus (sine wave speech), whether perceived as speech or as nonspeech sound, produces similar degrees of disruption and is less disruptive of serial recall than natural speech. This outcome suggests that the acoustic constituents of sound rather than its source are most influential in determining the impact of irrelevant material.

Adolescent↗
PubMed1994

Memory for pictures and sounds: independence of auditory and visual codes.

Three experiments examined the mnemonic independence of auditory and visual nonverbal stimuli in free recall. Stimulus lists consisted of (1) pictures, (2) the corresponding environmental sounds, or (3) picture-sound pairs. In Experiment 1, free recall was tested under three learning conditions: standard intentional, intentional with a rehearsal-inhibiting distracter task, or incidental with the distracter task. In all three groups, recall was best for the picture-sound items. In addition, recall for the picture-sound stimuli appeared to be additive relative to pictures or sounds alone when the distracter task was used. Experiment 2 included two additional groups: In one, two copies of the same picture were shown simultaneously; in the other, two different pictures of the same concept were shown. There was no difference in recall among any of the picture groups; in contrast, recall in the picture-sound condition was greater than recall in either single-modality condition. However, doubling the exposure time in a third experiment resulted in additively higher recall for repeated pictures with different exemplars than ones with identical exemplars. The results are discussed in terms of dual coding theory and alternative conceptions of the memory trace.

Auditory Perception↗
PubMedDate not supplied

Sound transmission into incubators in the neonatal intensive care unit.

OBJECTIVE: To measure the attenuation of sound by modern incubators. STUDY DESIGN: LEQ, LMAX, LPEAK, and frequency distribution were measured simultaneously inside and outside two recent model incubators. RESULTS: The attenuation of sound (outside minus inside) was 15 to 18 dBA with the motor off and 4 to 8 dBA with the motor on. There was a significant difference between incubators in their attenuation of sound. Octave band analysis showed attenuation in frequency bands of > 31.5 Hz with the motor off. With the motor on, the sound level inside the incubator was higher than outside at frequency bands of < 250 Hz. CONCLUSION: Caring for infants inside modern incubators reduces "averaged" sound exposure to levels near those recommended for the neonatal intensive care unit. Lower frequency sounds are louder inside the incubator and arise from the incubator motor.

Humans↗
PubMed1980

Sound stimulation available to the sheep foetus.

Work on the uterine sound environment has been carried out by implanting a hydrophone on the neck of the foetus in two pregnant ewes a few weeks before term. Stimulation with sounds of known amplitude and the use of calibrated microphones and a frequency analyser enabled us to assess (1) the amount of attenuation of sounds of different frequency when they had passed through the maternal tissues and amniotic fluid to become available to the foetus, (2) the absolute level of sound entering the amnion from within the mother and (3) the recognizability of external sound such as speech, when recorded from within the uterus. One puzzling feature of the results has been our inability to hear those sounds which are commonly believed to constitute a predominant stimulus for the foetus: those produced by the maternal cardiovascular system.

Acoustic Stimulation↗
PubMed1976

[Atrial flutter with an audible atrial sound (author's transl)].

In a case of rheumatic valve disease atrial sounds could be heard and recorded on the phonocardiogram during atrial flutter at a rate of 260/min and an atrioventricular block of 3:1 and 5:1. The atrial flutter sounds were also recorded in the apex-cardiogram and as a slight but rapid motion of the anterior mitral valve leaflet in the echocardiogram. These atrial sounds were recorded both in systole and diastole and disappeared after cardiac failure had been treated and sinus rhythm restored. This case and 19 others reported in the medical literature indicate that for atrial sounds to become audible requires high-grade atrioventricular block and increased atrial contractions with increased ventricular filling. The sounds have been proven to originate in the atrium, the characteristics of the sound being similar to those of an opening snap.

Atrial Flutter↗
PubMed1983

Perception of moving, sounding objects by four-month-old infants.

Infants and adults were presented with two moving objects accompanied by a single percussive sound. In different experiments, the sound occurred when one object moved through a particular spatial position, when it abruptly changed its direction of movement, or when it made contact with a rigid surface. Infants responded to the sound-object relationship whenever the sound occurred as the object changed direction, irrespective of its impacts with the surface. Adults, in contrast, responded to the sound-object relationship most clearly when sounds were synchronized with impacts. In infancy, perception of auditory-visual relationships thus depends in part on detection of discontinuities in the movement of a visible object.

Auditory Perception↗
PubMed2000

On cortical coding of vocal communication sounds in primates.

Understanding how the brain processes vocal communication sounds is one of the most challenging problems in neuroscience. Our understanding of how the cortex accomplishes this unique task should greatly facilitate our understanding of cortical mechanisms in general. Perception of species-specific communication sounds is an important aspect of the auditory behavior of many animal species and is crucial for their social interactions, reproductive success, and survival. The principles of neural representations of these behaviorally important sounds in the cerebral cortex have direct implications for the neural mechanisms underlying human speech perception. Our progress in this area has been relatively slow, compared with our understanding of other auditory functions such as echolocation and sound localization. This article discusses previous and current studies in this field, with emphasis on nonhuman primates, and proposes a conceptual platform to further our exploration of this frontier. It is argued that the prerequisite condition for understanding cortical mechanisms underlying communication sound perception and production is an appropriate animal model. Three issues are central to this work: (i) neural encoding of statistical structure of communication sounds, (ii) the role of behavioral relevance in shaping cortical representations, and (iii) sensory-motor interactions between vocal production and perception systems.

Animal Communication↗
PubMed1995

Increasing- and decreasing-loudness aftereffects: asymmetrical functions for absolute rate of sound level change in adapting stimulus.

After exposure to a tone of decreasing sound level, participants report that a steady tone increases in loudness; after exposure to an increasing sound level, they perceive a steady tone to decrease in loudness. The increasing-loudness aftereffect is the more sensitive to a difference between adapting and test frequencies, its absolute size becoming greater than that for decreasing-loudness aftereffect as frequencies are made to match. Although this asymmetry may reflect processing differences for the two directions of sound level change, a more parsimonious hypothesis entails perceived increasing loudness of short steady tones, in conjunction with differing levels of tonal adaptation across test frequencies. The former explanation is supported by the present report of another aftereffect asymmetry: With frequency the same for both adapting and test stimuli, so that tonal adaptation was nearly asymptotic during testing, altering the absolute rate of sound level change of the adapting stimulus had a greater effect on the magnitude of the increasing-loudness aftereffect. The first hypothesis is consistent with the percussive nature of natural sounds, few of which are steady: most of their sound levels rise almost instantaneously and decrease slowly.

Humans↗
PubMed2002

Auditory memory and the irrelevant sound effect: Further evidence for changing-state disruption.

Four experiments investigate the hypothesis that irrelevant sound interferes with serial recall of auditory items in the same fashion as with visually presented items. In Experiment 1 an acoustically changing sequence of 30 irrelevant utterances was more disruptive than 30 repetitions of the same utterance (the changing-state effect; Jones, Madden, & Miles, 1992) whether the to-be-remembered items were visually or auditorily presented. Experiment 2 showed that two different utterances spoken once (a heterogeneous compound suffix; LeCompte & Watkins, 1995) produced less disruption to serial recall than 15 repetitions of the same sequence. Disruption thus depends on the number of sounds in the irrelevant sequence. In Experiments 3a and 3b the number of different sounds, the "token-set" size (Tremblay & Jones, 1998), in an irrelevant sequence also influenced the magnitude of disruption in both irrelevant sound and compound suffix conditions. The results support the view that the disruption of memory for auditory items, like memory for visually presented items, is dependent on the number of different irrelevant sounds presented and the size of the set from which these sounds are taken. Theoretical implications are discussed.

Acoustic Stimulation↗
PubMed1995

Priming the identification of environmental sounds.

Three experiments were conducted using a repetition priming paradigm: Auditory word or environmental sound stimuli were identified by subjects in a pre-test phase, which was followed by a perceptual identification task using either sounds or words in the test phase. Identification of an environmental sound was facilitated by prior presentation of the same sound, but not by prior presentation of a spoken label (Experiments 1 and 2). Similarly, spoken word identification was facilitated by previous presentation of the same word, but not when the word had been used to label an environmental sound (Experiment 1). A degree of abstraction was demonstrated in Experiment 3, which revealed a facilitation effect between similar sounds produced by the same type of source. These results are discussed in terms of the Transfer Appropriate Processing, activation, and systems approaches.

Adult↗
PubMed1996

Effects of irrelevant sounds on phonological coding in reading comprehension and short-term memory.

The effects of irrelevant sounds on reading comprehension and short-term memory were studied in two experiments. In Experiment 1, adults judged the acceptability of written sentences during irrelevant speech, accompanied and unaccompanied singing, instrumental music, and in silence. Sentences varied in syntactic complexity: Simple sentences contained a right-branching relative clause (The applause pleased the woman that gave the speech) and syntactically complex sentences included a centre-embedded relative clause (The hay that the farmer stored fed the hungry animals). Unacceptable sentences either sounded acceptable (The dog chased the cat that eight up all his food) or did not (The man praised the child that sight up his spinach). Decision accuracy was impaired by syntactic complexity but not by irrelevant sounds. Phonological coding was indicated by increased errors on unacceptable sentences that sounded correct. These errors rates were unaffected by irrelevant sounds. Experiment 2 examined effects of irrelevant sounds on ordered recall of phonologically similar and dissimilar word lists. Phonological similarity impaired recall. Irrelevant speech reduced recall but did not interact with phonological similarity. The results of these experiments question assumptions about the relationship between speech input and phonological coding in reading and the short-term store.

Adolescent↗
PubMed2004

Human brain regions involved in recognizing environmental sounds.

To identify the brain regions preferentially involved in environmental sound recognition (comprising portions of a putative auditory 'what' pathway), we collected functional imaging data while listeners attended to a wide range of sounds, including those produced by tools, animals, liquids and dropped objects. These recognizable sounds, in contrast to unrecognizable, temporally reversed control sounds, evoked activity in a distributed network of brain regions previously associated with semantic processing, located predominantly in the left hemisphere, but also included strong bilateral activity in posterior portions of the middle temporal gyri (pMTG). Comparisons with earlier studies suggest that these bilateral pMTG foci partially overlap cortex implicated in high-level visual processing of complex biological motion and recognition of tools and other artifacts. We propose that the pMTG foci process multimodal (or supramodal) information about objects and object-associated motion, and that this may represent 'action' knowledge that can be recruited for purposes of recognition of familiar environmental sound-sources. These data also provide a functional and anatomical explanation for the symptoms of pure auditory agnosia for environmental sounds reported in human lesion studies.

Acoustic Stimulation↗
PubMed2003

Human auditory cortex tracks task-irrelevant sound sources.

The brain organizes sound into coherent sequences, termed auditory streams. We asked whether task-irrelevant sounds would be detected as separate auditory streams in a natural listening environment that included three simultaneously active sound sources. Participants watched a movie with sound while street-noise and sequences of naturally varying footstep sounds were presented in the background. Occasional deviations in the footstep sequences elicited the mismatch negativity (MMN) event-related potential. The elicitation of MMN showed that the regular features of the footstep sequences had been registered and their violations detected, which could only occur if the footstep sequence had been detected as a separate auditory stream. Our results demonstrate that sounds are organized into auditory streams irrespective of their relevance to ongoing behavior.

Acoustic Stimulation↗
PubMed2005

Perceptual categorization of sound spectral envelopes reflected in auditory-evoked N1m.

Magnetic responses to periodic complex sounds with equivalent acoustic parameters except for two different fundamental frequencies (F0) and 12 different spectral envelopes of vocal, instrumental, and linear shapes were recorded to determine the cortical representation of timbre categorization in humans. Responses at approximately 100 ms (N1m) to vocal and instrumental (nonlinear) sounds were localized significantly anterior to linear sound responses. N1m source strength for nonlinear sounds was significantly larger than that for linear sounds, and this difference was more marked in the left hemisphere than in the right. N1m peak latency only for vocal sounds was not affected by F0. Perceptual categorization was reflected in N1m source strength and location (linear or nonlinear), and in N1m latency (vocal or nonvocal).

Acoustic Stimulation↗
PubMed2000

Direct measurement of sound velocity in various specimens of breast tissue.

RATIONALE AND OBJECTIVES: Previous studies using ultrasound CT or clinical amplitude/velocity reconstruction imaging ultrasound may indicate that cancers differ from normal breast tissue by increased sound velocity. However, only limited experience with direct measurements of sound velocity exists. This study aimed to investigate sound velocity measured directly in a variety of breast specimens. METHODS: Sound velocity was measured directly by forceps in fresh breast specimens chosen to contain one type of tissue only. Eighty specimens (31 cancers, 18 benign changes of glandular/fibrous tissue, 22 fatty tissues, 5 fibroadenomas, 2 compound tissues, 1 phylloides tumor, and 1 inflammation) were analyzed. RESULTS: Ultrasound velocities in carcinoma, benign changes, fibroadenoma, inflammation, and the phylloides tumor were very similar, with almost complete overlap. In contrary, the ultrasound velocity of fatty tissue was significantly lower. Compound tissues containing fat had an intermediate sound velocity. CONCLUSIONS: Sound velocity may add complementary information to echogenicity (B-scan). Because fat lobules exhibit low ultrasound velocity and carcinomas do not, a locally exact combination of ultrasound velocity information and reflexivity information should allow improved breast cancer detection by ultrasound.

Breast Diseases↗
PubMed2005

Modeling of finite-amplitude sound beams: second order fields generated by a parametric loudspeaker.

The nonlinear interaction of sound waves in air has been applied to sound reproduction for audio applications. A directional audible sound can be generated by amplitude-modulating the ultrasound carrier with an audio signal, then transmitting it from a parametric loudspeaker. This brings the need of a computationally efficient model to describe the propagation of finite-amplitude sound beams for the system design and optimization. A quasilinear analytical solution capable of fast numerical evaluation is presented for the second-order fields of the sum-, difference-frequency and second harmonic components. It is based on a virtual-complex-source approach, wherein the source field is treated as an aggregation of a set of complex virtual sources located in complex distance, then the corresponding fundamental sound field is reduced to the computation of sums of simple functions by exploiting the integrability of Gaussian functions. By this result, the five-dimensional integral expressions for the second-order sound fields are simplified to one-dimensional integrals. Furthermore, a substantial analytical reduction to sums of single integrals also is derived for an arbitrary source distribution when the basis functions are expressible as a sum of products of trigonometric functions. The validity of the proposed method is confirmed by a comparison of numerical results with experimental data previously published for the rectangular ultrasonic transducer.

Acoustics↗
PubMed1979

Aspects of species recognition by sound in four species of damselfishes, genus Eupomacentrus (Pisces: Pomacentridae).

Members of four sympatric species of Eupomacentrus carry out reproductive activities at the same time of the year and produce similar pulsed courtship sounds. Such sounds are known to facilitate courtship among conspecifics. Consequently, members of the four species in the field and in the laboratory were tested with the various sounds to determine if they could distinguish their own species sounds from those produced by congeners. The differential responses clearly demonstrate species specific recognition by sound and indicate that the pulse interval and the number of pulses per sound are the important parameters for this recognition.

Animals↗
PubMed1997

Maternal perception of sound provoked fetal movement for antepartum assessment of fetal well-being.

OBJECTIVE: To assess the reliability and application of maternal perception of sound provoked fetal movement for antepartum assessment of fetal well-being. METHODS: Six hundred singleton high risk pregnant women of at least 32 weeks gestation were studied on 684 occasions. The response was compared with a nonstress test (NST) performed before a 3 second vibroacoustic stimulation with an electronic artificial larynx. The result of maternal perception of sound provoked fetal movement was compared to the NST and the perinatal outcome using sensitivity, specificity, negative predictive value, positive predictive value, and accuracy. RESULTS: On 684 occasions, a positive response to sound stimulation, recorded as a fetal movement by the mother, occurred on 642 occasions (93.9%) and was accompanied by a reactive NST on 630 occasions; giving a specificity of 97.1% and a negative predictive value of 98.1%. Results of maternal perception of sound provoked fetal movement and NST, performed within a week of delivery, in 560 women were compared with perinatal outcome. The maternal perception of sound provoked fetal movement test had better sensitivity (64.7%) for poor perinatal outcome than the NST (58.8%). Both tests were not different in specificity (96.3% vs 96.5%), positive predictive value (35.5% vs 34.5%), negative predictive value (98.9% vs 98.7%), and accuracy (95.4% vs 95.4%). CONCLUSION: The findings suggested that maternal perception of sound provoked fetal movement may be an effective screening test to identify fetal compromise in antepartum period. This test is a simple and inexpensive test for evaluating fetal well-being in primary health care setting.

Acoustic Stimulation↗