Honey bee orientation: a backup system for cloudy days

On cloudy days, honey bees are known to navigate to familiar food sources and orient their dances accurately. This capacity could be based on a magnetic compass sense, an ability to perceive the sun or patterns of polarized light through the clouds, or on the bees' memory of the diurnal course of the sun with respect to local landmarks. Experiments pitting these alternatives against one another demonstrate that the navigational backup system of bees is based on memory.     

Monitoring of swarming sounds in bee hives for early detection of the swarming period

Beekeeping, known as one of the oldest forms of agriculture, in its complexity requires control for honey production with what modern technology can offer. Honey is included in animal production implying that farmers have interest in big productions according to the best blooming time, the presence of parasites, the genetic strain of his bees and the swarming periods of the honeybees (queen and her workers leaving the hive).This last fact has a big economic interest for the beekeeper as swarming means honey loss since bees start collecting the honey to migrate. Here for a method that enables the prediction of the swarming is required to prevent the queen from leaving the hives. In this experiment an acoustic method based on labelling of sounds is proposed to predict the swarming period. Three hives were monitored during 270 h. The microphones were sited inside the hives together with a temperature and humidity sensor. The sounds were recorded with a sample rate of 2 kHz, and analyzed via Matlab and Cool Edit Pro. During this period 9 swarming activities occurred. Swarming is indicated by an increase in the power spectral density at about 110 Hz; approaching to swarm the sound augmented in amplitude and frequency to 300 Hz, occasionally a rapid change occurred from 150 Hz to 500 Hz. Another finding indicating the initiation of a swarming period is the raise in temperature from 33 °C to 35 °C until the actual time of swarming when the temperature starts dropping to 32 °C. With more activity, ventilation from bee wings causes drop of temperature. Less information comes from the correlation between sound and humidity since this parameter is too much influenced by the external conditions and no significant variation occurred according to a swarm. This increase of temperature, together with the changes in acoustical features of the sound recorded in the hive, may be used as a predictor for swarming of the bees to reduce honey loss.     

Sound Playback Experiments with Southern Right Whales (Eubalaena australis)

A variety of sound recordings were played to southern right whales. Whales approached the loudspeaker and made frequent sounds in response to recordings of other southern right whales, but swam away and made relatively few sounds in response to playbacks of water noise, 200-hertz tones, and humpback whale sounds. Thus it appears that southern right whales can differentiate between con-specific sounds and other sounds.     

大黄鱼的发声及信号特性研究

对大黄鱼Pseudosciaena crocea觅食及产卵时的发声及信号特性进行了研究。结果表明:不同行为下大黄鱼发声信号的频谱特性一致,即约在800 Hz频率处有一个明显的谱峰;但不同行为下发声的时域信号差距较大,即觅食时大黄鱼的发声信号都是简单的单脉冲,脉冲间隔大多集中在1~30 ms,脉冲间隔比较小,而产卵时大黄鱼的发声信号则大部分是连续的双脉冲或三脉冲,只有极个别的单脉冲或多脉冲,脉冲间隔则集中在100~130 ms,脉冲间隔要大得多。     

Dolphin vocalization mechanisms

Although humans have difficulty whistling when in a habitat that is more than 20 meters underwater, dolphins can make certain sounds at great depths through a related mechanism. Other dolphin sounds, such as clicks and complex buzzes, are produced by vibrations of the tissue of the nasal plugs, apparently without the use of the larynx; in these instances, the air sacs act as reservoirs. This was determined from studies of Tursiops truncatus and Delphinus delphis with harmless ultrasonic beams projected noninvasively to determine movements of the air sacs.     

三种螽斯鸣唱行为的比较研究

研究了优雅蝈螽、鼓翅鸣螽和暗褐蝈螽3种螽斯的鸣唱行为、鸣声种类.结果表明它们具有明显的日节律,优雅蝈螽和暗褐蝈螽属昼鸣性昆虫,鼓翅鸣螽属夜鸣性昆虫,但在竞鸣时日节律受到影响.通过录音回放和示波器摄影分析,确定优雅蝈螽的鸣声分为呼唤声、求偶声和惊叫声;暗褐蝈螽分为出短鸣、呼唤声和求偶声;鼓翅鸣螽分为呼唤声、求偶声、做爱声和惊叫声.优雅蝈螽雄虫的停鸣期长于雌虫的食包期,而暗褐蝈螽和鼓翅鸣螽的则相反.     

Aeroelastic flutter produces hummingbird feather songs

During courtship flights, males of some hummingbird species produce diverse sounds with tail feathers of varying shapes. We show that these sounds are produced by air flowing past a feather, causing it to aeroelastically flutter and generate flutter-induced sound. Scanning laser doppler vibrometery and high-speed video of individual feathers of different sizes and shapes in a wind tunnel revealed multiple vibratory modes that produce a range of acoustic frequencies and harmonic structures. Neighboring feathers can be aerodynamically coupled and flutter either at the same frequency, resulting in sympathetic vibrations that increase loudness, or at different frequencies, resulting in audible interaction frequencies. Aeroelastic flutter is intrinsic to stiff airfoils such as feathers and thus explains tonal sounds that are common in bird flight.     

人工神经网络对果蝇鸣声的分类识别

为了利用昆虫鸣声对昆虫进行种间或种下分类,对实验室环境下同种2个不同品系黑腹果蝇的飞行翅振鸣声进行了采集、分析,提取鸣声信号特征参数,并利用人工神经网络对采集的果蝇鸣声信号进行分类识别。结果表明,2个品系果蝇鸣声的基频均为236.86 Hz,有多个谐频,频率范围为0~4000 Hz,重叠较大;所建立的人工神经网络对种内不同品系果蝇鸣声的正确识别率均在75%以上,识别效果很好。研究结果为果蝇种下分类提供了新的方法和依据。     

网箱中黑鲷音响驯化的诱集效果探究

音响驯化作为鱼类行为控制技术之一,对海洋牧场内的鱼种行为控制有明显的作用。在驯化声源中,目标鱼种栖息海域背景噪声有望具有更佳的驯化效果。为此,在天然水域的网箱中采用录制的黑鲷栖息地背景噪声对黑鲷(Sparus macrocephalus)进行了音响驯化。由现场观察及数据分析,自然海域声音配合投饵能对黑鲷产生较好的集聚效果。黑鲷幼苗音响驯化一般经历3个过程,即环境适应,对饵料的需求达到一定量,建立声音与摄食之间的条件反射;黑鲷能识别声音,并维持一定的记忆时间。实验结果表明,采用海域背景噪声的音响驯化,配合投饵是一种有效的手段,并可以使黑鲷对声音的短期记忆转化为长期记忆。研究亮点:目前国内音响驯化研究环境主要停留在室内水槽中,自然水域网箱中的音响驯化国内未见报道。并且尝试将黑鲷放流海域的水下背景噪声作为驯化声源,探究鱼群诱集效果。另外将Atkinson-Shiffrin记忆理论运用到鱼类音响驯化领域中,探讨了定时声音刺激对黑鲷的行为反馈以及记忆变化的影响。     

Forms of Sounds as Shown on an Oscilloscope by Roulette Figures

It has been found that with an oscilloscope driven through a simple network of two resistors and two capacitors it is possible to produce recognizable pictures from speech sounds. These pictures thus become a natural phonetic alphabet, with which both standard pronunciation and the nuances of dialect and accent can be represented. While a given speech sound has certain invariant characteristics, it has also an overlay of accent, which can be represented in the alphabetic character. It is suggested that the technique may be useful in teaching deaf children to speak.     

Acoustic monitoring system to quantify ingestive behavior of free-grazing cattle

Estimating forage intake by free-grazing livestock is difficult and expensive. Previous approaches include behavioral observation, ratio techniques using indigestible markers, mechanical recording of ingestive jaw motion, and acoustic recording of ingestive behaviors. Acoustic recording shows great potential but has been limited by the difficulty and time required to manually identify and classify ingestive events. We present an acoustic recording and analysis system that automatically detects, classifies, and quantifies ingestive events in free-grazing beef cattle. The system utilizes a wide-frequency acoustic microphone close to the animal's mouth, mathematical signal analysis to detect and measure ingestive events, and streaming data analysis capable of handling an unlimited amount of data. Analysis parameters can be reconfigured for different animals, forages and other changing conditions. The system measures the acoustic parameters of ingestive events, such as duration, amplitude, spectrum and energy, which can support further event classification and become the inputs to a forage intake model. We validated our detection and classification technique against the results of trained human observers based on field studies with grazing steer. The software detected 95% of manually identified bites in an event-by-event comparison. Field observations and sound attenuation analysis indicate that sounds from adjacent livestock and ambient pastoral environments have an insignificant effect upon the integrity of the recorded acoustic data set. We conclude that wideband acoustic analysis allows us to identify ingestive events accurately and automatically over extended periods of time.     

Sound Production by the Satinfin Shiner,Notropis analostanus,and Related Fishes

Several sounds are produced by minnows. Only one is not of purely mechanical origin, and it is classed as a "biological" sound. This sound is variously produced by males when fighting and chasing as well as during courtship. Females emit a similar sound. Testosterone injections and elevated temperatures result in an increased rate of biological sound emission.     

Auditory sense in certain sphingid moths

Moths of the genus Celerio, hovering and feeding from blossoms, have been observed to react vigorously to high-pitched sounds. The acoustic receptor appears to involve the labial palps. Its characteristics have been determined from responses made, when the moth is exposed to artificial sound pulses, by an interneuron originating in its head. These responses have been found only in 4 out of 19 sphingid species tested.     

褐菖鲉发声系统形态结构及其发声特征研究

分别采用形态学和模拟领地入侵的方法研究了褐菖鲉发声系统和发声特征。结果表明,褐菖鲉发声系统由鱼鳔肌和鱼鳔组成。鱼鳔肌前方附着于颅骨的翼耳骨,后经第1～7肋骨,与鱼鳔背后侧部相连。在领地入侵模拟实验中,褐菖鲉发出了连续脉冲的“咕噜噜”声音,其平均脉冲周期为(32.6±2.6) ms,平均脉冲间隔为(51.8±81.4) ms, 主频为68～175 Hz。对单个声音脉冲中包涵的正弦波型的能量周期分析发现：其声音主频与最大能量周期的倒数一致,表明褐菖鲉是采用鱼鳔肌收缩的发声机制。     

Vibratory communication through living plants by a tropical wandering spider

Female Cupiennius salei pheromone on banana and Agave plants elicits patterned oscillations by the male. Resulting pulse trains of vibrations through the leaf average 76 hertz. The brief vibratory response by the otherwise immobile female hidden up to at least 1 meter away on another leaf guides the male across the plant to her location. Reciprocal signaling continues in the presence of random noise that masks the male's airborne sounds.     

Speech perception in infants

Discriminiationi of synthetic speech sounds was studied in 1- and 4-month-old infants. The speech sounds varied along an acoustic dimension previously shown to cue phonemic distinctions among the voiced and voiceless stop consonants in adults. Discriminability was measured by an increase in conditioned response rate to a second speech sound after habituation to the first speech sound. Recovery from habituation was greater for a given acoustic difference when the two stimuli were from different adult phonemic categories than when they were from the same category. The discontinuity in discrimination at the region of the adult phonemic boundary was taken as evidence for categorical perception.     

Auditory induction: perceptual synthesis of absent sounds

Within certain auditory patterns, fainter sounds may be "heard" clearly when replaced by louder sounds having appropriate spectral compositions. This auditory induction of fainter by louder sounds can cancel the perceptual effects of masking. Phonemic restorations, which have been reported previously, appear to be a specialized application to speech of the much broader phenomenon of auditory induction. The rules governing auditory induction indicate that it helps maintain stable auditory perception in our frequently noisy environment.     

The influence of respiratory disease on the energy envelope dynamics of pig cough sounds

The objective of this paper is to assess if the dynamics in the energy envelope of pig cough sounds are related to pathological conditions of the respiratory system. Two groups of pigs are compared. The first group, the sick pigs, is suffering from pneumonia by infection of Pasteurella Multocida. The second group, the control group, consists of healthy pigs which produced induced coughs by nebulisation of citric acid. The cough sounds of both groups were used to calculate the energy envelope, after which two signals are derived for further modelling. The first signal is an artificial step input, the second signal is part of the energy envelope of the cough signal that starts at the maximum level and decays in time. Using an autoregressive model estimation technique, the decay of the energy envelope is modelled as an input–output system. Based on the Young Identification Criterion (YIC) and R², the optimal model is proven to be a first order model with a first order denominator. Using this first order transfer function structure to model all cough sounds, the time constant of the simulated output is estimated based on the model parameters. The time constant shows significant higher values for the decay of the cough signals from pigs which are infected with Pasteurella Multocida compared to non-infected pigs (P < 0.0001). The results are in accordance with previous work in which pathological conditions have shown to influence cough sound duration. This modelling technique gives more insight in the effect of changes in lung condition on cough sound generation and might be incorporated in techniques for automatic cough evaluation.     

Sound production in the clownfish Amphiprion clarkii

Although clownfish sounds were recorded as early as 1930, the mechanism of sound production has remained obscure. Yet, clownfish are prolific "singers" that produce a wide variety of sounds, described as "chirps" and "pops" in both reproductive and agonistic behavioral contexts. Here, we describe the sonic mechanism of the clownfish Amphiprion clarkii.     

Perception of Ultrasound

Ultrasonic vibrations can be perceived as audible sounds when a piezoelectric transducer is pressed against certain areas of the human body. In the range of frequencies investigated (20 to 108 kcy/sec), the threshold of perception seemed to lie near the threshold of feeling (about 10(-4) watt/cm(2)), and the perceived audible sound appeared to be between 8 and 9 kcy/sec, as judged by six test subjects. The threshold of perception and the perceived frequency appear to be dependent upon the hearing characteristics of the individual.