Effects of energetic masking and informational masking on the perception of Cantonese tones in monosyllabic words

This study aimed to examine the effects of energetic masking and informational masking on Cantonese tone perception, the differential pattern that noise affects perception of the six Cantonese lexical tones, and the factors determining the effectiveness of masking on pitch perception. Four types of noise, including ten-talker babble, two-male-talker babble, two-female-talker babble, and speech-shaped noise, were used to represent conditions involving various amounts of energetic masking and informational masking. Two signal-to-noise ratios were employed for each type of noise. A quiet condition served as control. Twenty university students (8 male and 12 female) participated in the study. Each participant listened to and repeated Cantonese monosyllabic words in quiet and noise conditions respectively and the experimenter recorded the tones. The result showed that (1) Cantonese tone perception was largely prone to the combined effect of energetic masking and informational masking and it was more adversely affected by energetic masking than informational masking; (2) the effect of noise was more significant on contour tones than level tones, suggesting that, in noisy environment, noise exerted a larger effect on perception of pitch change than that of pitch level; (3) the masking effect of babble noise on pitch perception increased with the number of masker talkers.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Pixelating Familiar People in the Media: Should Masking Be Taken at Face Value?

This study questions the effectiveness of masking faces by means of pixelation on television or in newspapers. Previous studies have shown that masking just the face leads to unacceptably high recognition levels, making it likely that participants also use other cues for recognition, such as hairstyle or clothes. In the current study we investigate this possibility by means of an identification task in which participants had to identify (partially) masked images of familiar people. To demonstrate that non-facial cues become increasingly important for recognition as faces are masked more strongly, we manipulated the size of the masked area and the degree of pixelation. Confirming our expectations, increasing the size of masked area or its level of deterioration led to lower recognition rates. More importantly, also an interaction effect between the two variables emerged, showing that additional visual information partly compensates the downswing in recognition when masking becomes stronger. Although in some conditions low recognition rates were found, masking was never a hundred percent effective, making it clear that the media should approach this issue with care. Implications of our findings and future directions are considere

Perception of low-frequency acoustic signals by a harbour porpoise (Phocoena phocoena) in the presence of simulated offshore wind turbine noise

Using auditory evoked potential (AEP) methods, a study was conducted on a harbour porpoise (Phocoena phocoena) at the Dolfinarium Harderwijk in The Netherlands. The study measured the audible range of wind turbine sounds and their potential masking effects on the acoustic perception of the animal. AEPs were evoked with two types of acoustic stimuli: (1) click-type signals and (2) amplitude-modulated signals. The masking noise resembling the underwater sound emissions of an operational wind turbine was simulated. At first, the animal’s hearing threshold was measured at frequencies between 0.7 and 16 kHz. Subsequently, these measurements were repeated at frequencies between 0.7 and 2.8 kHz in the presence of two different levels of masking noise. The resulting data show a masking effect of the simulated wind turbine sound at 128 dB re 1 μPa at 0.7, 1.0, and 2.0 kHz. This masking effect varied between 4.8 and 7.3 dB at those frequencies. No significant masking was measured at a masking level of 115 dB re 1 μPa. The available data indicate that the potential masking effect would be limited to short ranges in the open sea, but limitations exist to this conclusion and all estimates are based on existing turbine types, not taking into account future developments of larger and potentially noisier turbine types

Statistical Inference in a Simple Linear Model Under Microaggregation

A problem statistical offices are increasingly faced with is guaranteeing confidentiality when releasing microdata sets. One method to provide safe microdata is to reduce the information content of a data set by means of masking procedures. A widely discussed masking procedure is microaggregation, a technique where observations are grouped and replaced with their corresponding group means. However, while reducing the disclosure risk of a data file, microaggregation also affects the results of statistical analyses. We focus on the effect of microaggregation on a simple linear model. In a previous paper we have shown how to correct for the aggregation bias of the naive least-squares estimator that occurs when the dependent variable is used to group the data. The present paper deals with the asymptotic variance of the corrected least-squares estimator and with the asymptotic variance of the naive least-squares estimator when either the dependent variable or the regressor is used to group the data. We derive asymptotic confidence intervals for the slope parameter. Furthermore, we show how to test for the significance of the slope parameter by analyzing the effect of microaggregation on the asymptotic power function of the naive t-test

Fault tolerant model predictive control of open channels

Automated control of water systems (irrigation canals, navigation canals, rivers etc.) relies on the measured data. The control action is calculated, in case of feedback controller, directly from the on-line measured data. If the measured data is corrupted, the calculated control action will have a different effect than it is desired. Therefore, it is crucial that the feedback controller receives good quality measurement data. On-line fault detection techniques can be applied in order to detect the faulty data and correct it. After the detection and correction of the sensor data, the controller should be able to still maintain the set point of the system. In this paper this principle using the sensor fault masking is applied to model predictive control of open channels. A case study of a reach of the northwest of the inland navigation network of France is presented. Model predictive control and water level sensor masking is applied.Peer ReviewedPostprint (published version

The Connection between Body Representation and Tactile Sensation Thresholds

In order to accurately interpret tactile information, the brain needs to have an accurate representation of the body to which to refer the sensations. Despite this, body representation has only recently been incorporated into the study of tactile perception. The effect of body representation on tactile thresholds was explored in two different ways. First, tendon vibration illusions were used to investigate whether distortions of body representation affect tactile sensations. Tactile acuity and sensitivity were increased when perceived size of the arm and waist were altered. Secondly, masking was used to investigate whether stimulation to one part of the body representation alters thresholds at other sites. Contralateral masking on the arms was found, along with spatial tuning of this effect. Masking through the body was also demonstrated by measuring the effect of a masking stimulus on the back on the tactile sensitivity of the corresponding point on the front