Control of responding by sounds of different quality: an evolutionary analysis.

Two experiments investigated the acquisition of discriminations between two acoustic stimuli of different quality (noise bursts vs. a 2-kHz pulsed signal) when features of the everyday environment were incorporated into the experiments. In Experiment 1, rats were trained, using food, to press a lever. Throughout all sessions, 5-s trials of noise bursts (the random stimulus) were presented, after variable intertrial intervals, through a remote speaker mounted outside the experimental enclosure. The noise burst occurred randomly with respect to reinforcement of lever pressing and had no programmed relationship to the animal's behavior. When lever pressing was established, the 2-kHz signal was presented through a speaker adjacent to the response lever according to a different set of variable intertrial intervals. A response in the presence of the 2-kHz signal terminated the trial and was reinforced. The 2-kHz signal acquired control of responding within the first few trials, whereas the random stimulus exerted no control of responding. In Experiment 2, rats were trained to press the lever in the presence of the 2-kHz signal presented through the adjacent speaker on a variable intertrial interval. After 14 sessions, 5-s trials of noise bursts (random stimulus) were presented through the remote speaker on the second variable intertrial interval. The random stimulus initially elicited exploratory behavior, which then rapidly declined. Subsequently, the random stimulus exerted no or weak control of responding. The introduction of the random stimulus had no effect on responding in the presence of the adjacent stimulus. In Experiments 3 and 4 the random stimulus was presented through the adjacent speaker, and the stimulus correlated with reinforcement was presented through the remote speaker. In both experiments, there was persistent control of responding by the random stimulus and slow development of control by the stimulus correlated with reinforcement. In Experiment 5, both stimuli were presented through the adjacent speaker. There was persistent control of responding by the random stimulus.     

Knowing letter names and learning letter sounds: a causal connection

Two experiments tested the common assumption that knowing the letter names helps children learn basic letter-sound (grapheme-phoneme) relation because most names contain the relevant sounds. In Experiment 1 (n=45), children in an experimental group learned English letter names for letter-like symbols. Some of these names contained the corresponding letter sounds, whereas others did not. Following training, children were taught the sounds of these same "letters." Control children learned the same six letters, but with meaningful real-word labels unrelated to the sounds learned in the criterion letter-sound phase. Differences between children in the experimental and control groups indicated that letter-name knowledge had a significant impact on letter-sound learning. Furthermore, letters with names containing the relevant sound facilitated letter-sound learning, but not letters with unrelated names. The benefit of letter-name knowledge was found to depend, in part, on skill at isolating phonemes in spoken syllables. A second experiment (n=20) replicated the name-to-sound facilitation effect with a new sample of kindergarteners who participated in a fully within-subject design in which all children learned meaningless pseudoword names for letters and with phoneme class equated across related and unrelated conditions.     

Do you remember where sounds,pictures and words came from? The role of the stimulus format in object location memory

Contrasting results in visual and auditory spatial memory stimulate the debate over the role of sensory modality and attention in identity-to-location binding. We investigated the role of sensory modality in the incidental/deliberate encoding of the location of a sequence of items. In 4 separated blocks, 88 participants memorised sequences of environmental sounds, spoken words, pictures and written words, respectively. After memorisation, participants were asked to recognise old from new items in a new sequence of stimuli. They were also asked to indicate from which side of the screen (visual stimuli) or headphone channel (sounds) the old stimuli were presented in encoding. In the first block, participants were not aware of the spatial requirement while, in blocks 2, 3 and 4 they knew that their memory for item location was going to be tested. Results show significantly lower accuracy of object location memory for the auditory stimuli (environmental sounds and spoken words) than for images (pictures and written words). Awareness of spatial requirement did not influence localisation accuracy. We conclude that: (a) object location memory is more effective for visual objects; (b) object location is implicitly associated with item identity during encoding and (c) visual supremacy in spatial memory does not depend on the automaticity of object location binding.     

Fast and unintentional evaluation of emotional sounds: evidence from brief segment ratings and the affective Simon task

In the present study, we raised the question of whether valence information of natural emotional sounds can be extracted rapidly and unintentionally. In a first experiment, we collected explicit valence ratings of brief natural sound segments. Results showed that sound segments of 400 and 600?ms duration—and with some limitation even sound segments as short as 200?ms—are evaluated reliably. In a second experiment, we introduced an auditory version of the affective Simon task to assess automatic (i.e. unintentional and fast) evaluations of sound valence. The pattern of results indicates that affective information of natural emotional sounds can be extracted rapidly (i.e. after a few hundred ms long exposure) and in an unintentional fashion.     

Concurrent schedules: Quantifying the aversiveness of noise

Four hens worked under independent multiple concurrent variable-interval schedules with an overlaid aversive stimulus (sound of hens in a poultry shed at 100dBA) activated by the first peck on a key. The sound remained on until a response was made on the other key. The key that activated the sound in each component was varied over a series of conditions. When the sound was activated by the left (or right) key in one component, it was activated by the right (or left) key in the other component. Bias was examined under a range of different variable-interval schedules, and the applicability of the generalized matching law was examined. It was found that the hens' behavior was biased away from the sound independently of the schedule in effect and that this bias could be quantified using a modified version of the generalized matching law. Behavior during the changeover delays was not affected by the presence of the noise or by changes in reinforcement rate, even though the total response measures were. Insensitivity shown during the delay suggests that behavior after the changeover delay may be more appropriate as a measure of preference (or aversiveness) of stimuli than are overall behavior measures.     

Teaching letter sounds to kindergarten English language learners using incremental rehearsal

Proficiency in letter–sound correspondence is important for decoding connected text. This study examined the effects of an evidence-based intervention, incremental rehearsal (IR), on the letter–sound expression of three kindergarten English language learners (ELLs) performing below the district benchmark for letter–sound fluency. Participants were native speakers of Hmong, Spanish, and Polish. A multiple-baseline design across sets of unknown letter sounds was used to evaluate the effects of IR on letter–sound expression. Visual analysis of the data showed an increase in level and trend when IR was introduced in each phase. Percentage of all non-overlapping data (PAND) ranged from 95% to 100%. All participants exceeded expected growth and reached the spring district benchmark for letter–sound fluency. Results suggest that IR is a promising intervention for increasing letter–sound expression for ELLs who evidence delays in acquiring letter sounds.     

A PROPOSAL FOR THE CREATION OF A HUMAN AND COMPUTER METALANGUAGE

Since the beginning of the last century, with the development of the Theory of Relativity, an ever-growing gap has come into being between our knowledge about the structure of the world around us and our ability to conceptualize it. Because language plays a major role in our ability to describe the world and our role within it, a need has been created to match the capabilities of language to the knowledge we currently possess about the world we inhabit. This article will focus on two main arguments: (A) our ability to describe and conceptualize the world using a language that is limited, problematic and finite and (B) The possibility of developing a new language based on other principles than those governing verbal speech, which can deal with these limitations and problems and which is better suited to describing the world as we know it today.     

Hearing living symbols and nonliving icons: Category specificities in the cognitive processing of environmental sounds

The neurocognitive processing of environmental sounds and linguistic stimuli shares common semantic resources and can lead to the activation of motor programs for the generation of the passively heard sound or speech. We investigated the extent to which the cognition of environmental sounds, like that of language, relies on symbolic mental representations independent of the acoustic input. In a hierarchical sorting task, we found that evaluation of nonliving sounds is consistently biased toward a focus on acoustical information. However, the evaluation of living sounds focuses spontaneously on sound-independent semantic information, but can rely on acoustical information after exposure to a context consisting of nonliving sounds. We interpret these results as support for a robust iconic processing strategy for nonliving sounds and a flexible symbolic processing strategy for living sounds.     

Do experiments in the virtual world effectively predict how pedestrians evaluate electric vehicle sounds in the real world?

New laws stipulate that electric vehicles must emit additional sounds to alert pedestrians of the vehicles’ approach to prevent potential collisions. These new sounds will also influence pedestrians’ impression of the vehicle brand. A methodology has been developed to evaluate electric vehicle (EV) sounds in a virtual-world environment by assessing; (a) detectability and recognisability to ensure pedestrians’ safety, and (b) emotional evaluation of the sound quality to determine its impact on the perception of the vehicle brand. This experimental study examines external validity of the methodology. Fourteen participants evaluated an EV, emitting three sounds, in a traffic scenario in a real-world and a virtual-world environment. The traffic scenario involved a pedestrian ‘standing’ at a residential road junction while the EV travelled at 12 mph from behind the pedestrian, arriving at the junction at one of two pre-set times. Results show that the presented virtual-world methodology accurately predicts pedestrians’ evaluation of detectability of EV sounds and powerfulness and pleasantness of the vehicle brand in the corresponding real-world scenario. It also predicts the ranked order of sounds in the real-world for detection distance and recognisability. Arguably, for similar methods and setups, virtual-worlds would effectively predict pedestrians’ evaluation in the real-world. Interestingly, varying a vehicle’s arrival time, just like a real-world scenario, is found to affect pedestrians’ detection rate. Unlike experiments in the real-world, the presented methodology for experiments in virtual-world benefits from being reliable, quick, easy to implement, with more experimental control and options to easily manipulate any experiment variables.