Auditory Psychophysics in Birds: the Effects of Unique Noise on Sensitivity

<p>The performances of observers in auditory experiments are likely to be affected by extraneous noise from physiological or neurological sources and also by decision noise. Attempts have been made to measure the characteristics of this noise, in particular its level relative to that of masking noise provided by the experimenter. This study investigated an alternative approach, a method of analysis which seeks to reduce the effects of extraneous noise on measures derived from experimental data. Group-Operating-Characteristic (GOC) analysis was described by Watson (1963) and investigated by Boven (1976). Boven distinguished between common and unique noise. GOC analysis seeks to reduce the effects of unique noise. In the analysis, ratings of the same stimulus on different occasions are sunned. The cumulative frequency distributions of the resulting variable define a GOC curve. This curve is analogous to an ROC curve, but since the effects of unique noise tend to be averaged out during the summation, the GOC is less influenced by extraneous noise. The amount of improvement depends on the relative variance of the unique and common noise (k). Higher levels of unique noise lead to greater improvement. In this study four frequency discrimination experiments were carried out with pigeons as observers, using a three-key operant procedure. In other experiments, computer-simulated observers were used. The first two pigeon experiments, and the simulations, were based on known distributions of common noise. The ROCs for the constructed distributions provided a standard with which the GOC curve could be compared. In all cases the analysis led to improvements in the measures of performance and increased the match of the experimental results and the ideal ROC. The amount of improvement, as well as reflecting the level of unique noise, depended on the number of response categories. With smaller numbers of categories, improvement was reduced and k was underestimated. Since the pigeon observers made only "yes" or "no" responses, the results for the pigeon experiments were compared with the results of simulations with known distributions in order to obtain more accurate estimates of k. The third and fourth pigeon experiments involved frequency discrimination tasks with a standard of 450 Hz and comparison frequencies of 500, 600, 700, 800 and 900 Hz, and 650 Hz, respectively. With the multiple comparison frequencies the results were very variable. This was due to the small number of trials for each frequency and the small number of replications. The results obtained with one comparison frequency were more orderly but, like those of the previous experiment, were impossible to distinguish from those which would be expected if there was no common noise. A final set of experiments was based on a hardware simulation. Signals first used in the fourth pigeon experiment were processed by a system made up of a filter, a zero-axis crossing detector and a simulated observer. The results of these experiments were compatible with the possibility that the amount of unique noise in the pigeon experiments overwhelmed any evidence of common noise.</p>

Auditory Psychophysics in Birds: the Effects of Unique Noise on Sensitivity

<p>The performances of observers in auditory experiments are likely to be affected by extraneous noise from physiological or neurological sources and also by decision noise. Attempts have been made to measure the characteristics of this noise, in particular its level relative to that of masking noise provided by the experimenter. This study investigated an alternative approach, a method of analysis which seeks to reduce the effects of extraneous noise on measures derived from experimental data. Group-Operating-Characteristic (GOC) analysis was described by Watson (1963) and investigated by Boven (1976). Boven distinguished between common and unique noise. GOC analysis seeks to reduce the effects of unique noise. In the analysis, ratings of the same stimulus on different occasions are sunned. The cumulative frequency distributions of the resulting variable define a GOC curve. This curve is analogous to an ROC curve, but since the effects of unique noise tend to be averaged out during the summation, the GOC is less influenced by extraneous noise. The amount of improvement depends on the relative variance of the unique and common noise (k). Higher levels of unique noise lead to greater improvement. In this study four frequency discrimination experiments were carried out with pigeons as observers, using a three-key operant procedure. In other experiments, computer-simulated observers were used. The first two pigeon experiments, and the simulations, were based on known distributions of common noise. The ROCs for the constructed distributions provided a standard with which the GOC curve could be compared. In all cases the analysis led to improvements in the measures of performance and increased the match of the experimental results and the ideal ROC. The amount of improvement, as well as reflecting the level of unique noise, depended on the number of response categories. With smaller numbers of categories, improvement was reduced and k was underestimated. Since the pigeon observers made only "yes" or "no" responses, the results for the pigeon experiments were compared with the results of simulations with known distributions in order to obtain more accurate estimates of k. The third and fourth pigeon experiments involved frequency discrimination tasks with a standard of 450 Hz and comparison frequencies of 500, 600, 700, 800 and 900 Hz, and 650 Hz, respectively. With the multiple comparison frequencies the results were very variable. This was due to the small number of trials for each frequency and the small number of replications. The results obtained with one comparison frequency were more orderly but, like those of the previous experiment, were impossible to distinguish from those which would be expected if there was no common noise. A final set of experiments was based on a hardware simulation. Signals first used in the fourth pigeon experiment were processed by a system made up of a filter, a zero-axis crossing detector and a simulated observer. The results of these experiments were compatible with the possibility that the amount of unique noise in the pigeon experiments overwhelmed any evidence of common noise.</p>

Research of the Stegosignal Propagation through the Acoustic Environment

The paper considers two main applications of stegosystems: as a digital watermark, for copyright protection, and as a method for secretly transmitting information through an acoustic environment. A stegosystem is studied theoretically and experimentally when information is transmitted over different distances in an acoustic medium in the presence of extraneous noise. Nowadays great attention is paid to the protection of intellectual property. Illegal distribution of media content, including copies of musical compositions, is widespread and reaches unprecedented proportions. Protecting audio files from unauthorized copying and using becomes increasingly important. Digital watermarks are a promising method for solving this problem. The purpose of the article is to develop an effective method for protecting audio files from illegal use by embedding a digital watermark (DW). After detection the illegal distribution of their product, the copyright holder will be able to track the presence of the digital watermark and apply to the court for damages.

Assessment of digital image correlation vibrometry in the presence of thermal flow disturbance

Digital Image Correlation (DIC) is an image-based method for measuring displacement and/or stain on the surface of a structure. When coupled with a stereo pair of highspeed cameras, DIC can also capture three-dimensional dynamic deformation of a structure under vibratory loading. However, high frequency and small amplitude displacement typically associated with structural vibrations mean that extra care is required during measurement and data processing. It becomes more challenging when thermal disturbances are present in the optical path, for example from a heated air flow, which introduces extraneous noise due to disturbances in the refractive index. In the present study, a simple composite plate was vibrated under a shaker excitation and stereo DIC measurements were performed. The obtained vibratory displacement results were compared against accelerometers and a laser Doppler vibrometer. Heated air flow was introduced in front of the plate to observe the effects of thermal disturbances on the DIC measurements. Although the contributions from the thermal disturbances were clearly visible in the DIC displacement data, it was shown that the vibratory deflections of the structure could still be extracted by post processing of the DIC data.

The Design and Construction of an Expressive Mechatronic Chordophone

<p><b>Mechatronic chordophones are stringed instruments that integrate mechanical components and electronics to make music. These instruments offer precise control over multiple sound parameters and expressive techniques for enhanced musical expression.</b></p> <p>There have been multiple successful mechatronic chordophone designs,from robotic slide guitars to bass guitar robots. Among these designs are plucked string and pitch shifting mechatronic chordophones, which make music by exciting the string with a picking mechanism and selecting musical notes with a pitch shifter mechanism. This configuration enables these systems to enhance their musical performance through pitch-based expressive techniques and micro tonal pitches. </p> <p>However, even if these instruments can achieve speeds and precision beyond the capabilities of a human performer, their expressive capabilities are limited. It is difficult for mechatronic chordophones to perform dynamic variations and expressive techniques,and the presence of extraneous noise usually interferes with their musical performance. Furthermore, it is still challenging for users to control such instruments.</p> <p>We have built two mechatronic chordophones. The first is Protochord, a mechatronic monochord prototype. We used this system as a platform for iterative design to develop new expressive mechatronic chordophone subsystems. The second is Azure Talos,a multi-string mechatronic chordophone designed to outperform other existing systems and to afford a wide array of parameters for musical expression. </p> <p>Our research has led to the development of novel mechatronic chordophone subsystems such as: a revolving picking mechanism with superior dynamic variation capabilities compared to that of other existing designs; a fast and precise robot arm pitch shifting mechanism that affords pitch-based expressive techniques; and an optical pickup that rejects extraneous noise. We have demonstrated the technical capabilities of these designs through quantitative evaluation processes, in many cases providing the first set of quantitative tests in the literature of these types of sub-assemblies and systems. A key aim is to provide standards and benchmarks in evaluation criteria which may be used in the development of new mechatronic chordophones.</p> <p>Finally, we developed strategies to assess Azure Talos' musical capabilities through standard guitar techniques, repertoire examples,and creative musical explorations.</p>

The Design and Construction of an Expressive Mechatronic Chordophone

<p><b>Mechatronic chordophones are stringed instruments that integrate mechanical components and electronics to make music. These instruments offer precise control over multiple sound parameters and expressive techniques for enhanced musical expression.</b></p> <p>There have been multiple successful mechatronic chordophone designs,from robotic slide guitars to bass guitar robots. Among these designs are plucked string and pitch shifting mechatronic chordophones, which make music by exciting the string with a picking mechanism and selecting musical notes with a pitch shifter mechanism. This configuration enables these systems to enhance their musical performance through pitch-based expressive techniques and micro tonal pitches. </p> <p>However, even if these instruments can achieve speeds and precision beyond the capabilities of a human performer, their expressive capabilities are limited. It is difficult for mechatronic chordophones to perform dynamic variations and expressive techniques,and the presence of extraneous noise usually interferes with their musical performance. Furthermore, it is still challenging for users to control such instruments.</p> <p>We have built two mechatronic chordophones. The first is Protochord, a mechatronic monochord prototype. We used this system as a platform for iterative design to develop new expressive mechatronic chordophone subsystems. The second is Azure Talos,a multi-string mechatronic chordophone designed to outperform other existing systems and to afford a wide array of parameters for musical expression. </p> <p>Our research has led to the development of novel mechatronic chordophone subsystems such as: a revolving picking mechanism with superior dynamic variation capabilities compared to that of other existing designs; a fast and precise robot arm pitch shifting mechanism that affords pitch-based expressive techniques; and an optical pickup that rejects extraneous noise. We have demonstrated the technical capabilities of these designs through quantitative evaluation processes, in many cases providing the first set of quantitative tests in the literature of these types of sub-assemblies and systems. A key aim is to provide standards and benchmarks in evaluation criteria which may be used in the development of new mechatronic chordophones.</p> <p>Finally, we developed strategies to assess Azure Talos' musical capabilities through standard guitar techniques, repertoire examples,and creative musical explorations.</p>

Systemic Racism in EEG Research: Considerations and Potential Solutions

The current theoretical paper discusses the unintended systemic racism and racial biases that impact neuroscience, specifically in research utilizing electroencephalography (EEG). As a popular technique in affective science research, EEG requires adherence between the electrode and scalp to measure brain activity. To obtain high-quality data, various factors such as hair length, hair type, body movement, and/or extraneous noise from the environment are taken into consideration. As EEG researchers attempt to gather good-quality data, the recruitment and retention of Black American participants is challenging due to hairstyles commonly worn by Black American participants (e.g., cornrows, braids) and hair type. Taken together, the systemic lack of data from Black American participants renders research findings less generalizable and causes disparities in theoretical knowledge applicable to this population. To address this disparity, innovative solutions invented by bioengineers are discussed.

The Use of Time-Scale Analysis in Forensic Acoustical Investigations

The identification and characterization of noise events is one of the most important task in acousticalforensic analysis. In this field it is often fundamental to distinguish, within a complex acoustical framework, thedifferent noise events, especially because, in many cases, the operator cannot be present at the measurements. Itis fundamental to be able to distinguish the atypical or extraneous noise events from the specific ones underinvestigation and know what type of sources make up the noise climate. To this aim is essential to develop a time- frequency analysis technique able to overcame the known limitations of the “traditional” 1/3 of octave frequencyanalyses. In this paper a novel technique, based on multiresolution analysis, has been developed and applied tosome forensic “typical” problems, showing that a suitable choice of the analysis parameters can be able to answerto the main questions of this field

Implementation of the Ffowcs Williams-Hawkings Equation: Predicting the Far Field Noise From Airfoils While Using Boundary Layer Tripping Mechanisms

A study was done to investigate how boundary layer tripping mechanisms can affect the ability of a permeable surface FW-H solver to predict the far field noise emanating from an airfoil trailing edge. The far field noise in a baseline airfoil as well as the baseline airfoil fitted with fin let fences was analyzed. Two numerical boundary layer tripping mechanisms were implemented. The results illustrated the importance of choosing a permeable integration surface that is outside any high frequency waves emanating from the trip region. The results also illustrated the importance of choosing a boundary layer tripping mechanism that minimizes any extraneous noise so that an integration surface can be taken close to the airfoil.