声学参数理论1.A 计权声压级声压有效值定义为⼀定时间间隔中，瞬时声压对时间的均⽅根值，⽤p e表⽰：将声压有效值p e与基准量p0之⽐的对数乘以20 便可以得到声压pe的声压级，⽤L p 表⽰：A 计权声压级（简称A 声级）⽤以模拟55dB以下低强度噪声特性，对1000Hz 以下的低中频段衰减，其结果与⼈对声⾳的感知相近。
2.响度响度（Loudness）是基于⼈⽿对声⾳频谱掩蔽特性的反映⼈⽿对声⾳强弱感知程度的⼼理声学参数，单位为宋（sone），规定1000Hz纯⾳的声压级为40dB时的响度为1宋。
国际标准ISO532 规定了A、B 两种计算稳态噪声响度的计算⽅法：a)Stevens⽅法（ISO532A）：详细内容参见标准ISO532-A-1975 和ANSIS3.4-1980。
其数学表达式为：b)Zwicker⽅法（ISO532B）（本⽂所采⽤⽅法）：Zwicker法适⽤于⾃由声场或混响声场的计算，在通常情况下⼀般采⽤Zwicker法的响度计算模型。
Zwicker法以1/3倍频程频谱为依据，引⼊了特征频带和特征响度的概念，⾸先计算每个特征频带特征响度，再由此来得到总响度值。
根据Zwicker的响度理论，通过激励E可以计算得到特征响度，其计算公式：式中：E TQ为绝对听阈下的激励（安静状况下），E0为基准声强下的激励，被计算声⾳的特征频带声压级作为激励级E。
对特征响度在0-24 Bark域上积分，即可得到总响度：注：掩蔽效应是指由于⼀个声⾳的存在⽽使另⼀个声⾳听阈提⾼的现象。
⼈类的听觉系统具有滤波特性，即频率选择性。
为了描述⼈⽿的频率选择特性和掩蔽效应，Zwicker假设⼈的听觉系统将声⾳信号分量分成24个频带，当确定了⼀个声⾳的频率时，能够产⽣掩蔽效应的另外⼀个声⾳的频率范围称为“特征频带”，单位是Bark。
在Zwicker模型中，特征频带Bark 数z和频率f(Hz)的对应关系可近似表达为：3.尖锐度尖锐度（Sharpness）是描述⾼频成分在声⾳频谱中所占⽐例的物理量，主要反映⼈们主观上对⾼频段声⾳刺⽿程度的感受，单位为acum。
1. We don't know very much about the brain, and as a _____, scientists have not been able to find out very much about how it works.A. complexityB. screenC. structureD. consequence2. Scientists are trying to _____ new ways to study the brain.A. expectB. developC. reactD. hold3. When the man spilled the hot coffee on Sarah, she _____ by jumping up and screaming.A. expectedB. reactedC. developedD. discovered4. The _____ of the human brain is well known, and scientists find it very difficult to understand.A. complexityB. structureC. screenD. consequence5. The frontal lobe is a physical _____ of the brain.A. screenB. structureC. complexityD. consequence6. The brain _____ mental processes, such as thinking.A. discoversB. expectsC. deals withD. reacts7. She _____ an experiment to figure out how our brains process information.A. reactedB. expectedC. heldD. performed8. The doctor looked at the picture of the brain on a computer _____.A. complexityB. screenC. consequenceD. structure9. The scientist did not ______ male brains to be different from female brains before he started his research, and he was surprised to find out how different they were.A. expectB. deal withC. reactD. develop10. Scientists have _____ many new facts about the brain in recent years.A. expectedB. performedC. discoveredD. reacted1. It is now possible to view three- dimensional pictures of the human brain on computer screens.2. The function of the new machine is to test human brain cells.3. The famous neuroscientist discovered a new treatment for brain cancer.4. The scientist completed her research study, and she published her finding in a medical journal.5. Machines that can be used for imaging include cameras and X-ray machines.6. The cells of the brain that send messages from the brain to other parts of the body are called neurons .7. The discovery that adult brains are different from children's brains had great implications for the way diseases of the brain are treated.8. Scientists study images of the human brain to learn about differences between men and women.1. New technology allows us to see _____.A. fMRIs and PETsB. the effects of brain injuryC. inside a live brainD. the shape of the brain2. fMRI and PET machines create pictures and movies that show brain _____.A. activityB. healthC. intelligenceD. size3. New research shows differences between _____.A. children and adult brainsB. large and small brainsC. male and female brainsD. sick and healthy brains4. Scientists know everything about the human brain.A. trueB. false5. The frontal lobe is one of the physical structures within the brain.A. trueB. false6. There are 10,000 neurons in the human brain.A. trueB. false7. The connections between neurons are very complex.A. trueB. false8. The development of new technology that can see deep inside a living brain allows for new discoveries in human brain research.A. trueB. false1. I tried to interpret the results of the scientist's experiment, but it was too difficult.2. The research revealed many surprising new facts about the brain.3. Scientists have found many similarities between male and female brains, but also some differences.4. Women are usually thought to be more emotional than men, but undersome circumstances, men can be more emotional than women.5. This part of the brain processes information that we get from seeing and hearing the world around us.6. The brains of some individuals work differently than the brains of the majority of people.7. Generally, men have a(n) reputation for hiding their emotions.8. The scientist gave a lecture on several different aspects of the brain.9. Now, researchers realize that male and female brains are different from each other, but previously they thought that they were the same.10. The scientist examined the man's brain carefully to see how it reacted to images.1. There is a(n) stereotype that girls are easily frightened and boys are brave.2. Neurons transmit messages to each other.3. When girls and boys get older and go through puberty, their hormones become very active.4. From this finding, we can infer that some medicines that doctors have been giving to women may not be healthy for them to take.5. Some areas of the brain, such as the area that controls emotions, are proportionately larger in men than they are in women.6. Monkeys have small brains relative to humans.7. It is incorrect to make the assumption that men are smarter than women because their brains are bigger.8. It is a natural instinct for a mother to take care of and protect her baby.9. Sensory organs like the nose and ears send signals to the brain.1. Social pressures are the main reason why men and women are different. false2. Social and biological factors create differences between men andtruewomen.3. Men and women are different because they communicate differently. false4. Male and female brains differ in structure and in the way messagestrueare transmitted.5. Brain research is done on men because they think more clearly thanfalse women.6. Research on the brain should include studies of how women's brainstruework.g 1. hypothalamus a. pain suppressionf2. frontal lobe b. spatial perceptiond 3. limbic cortex c. memory and spatial navigationb 4. parietal cortex d. emotionsc 5. hippocampus e. emotional memorye 6. amygdala f. decision-making and problem-solvinga 7. periaqueductal grey g. basic instincts (such as food intake)1. hypothalamus no information on size2. frontal lobe bigger in women3. limbic cortex bigger in women4. parietal cortex bigger in men5. hippocampus bigger in women6. amygdala bigger in men7. periaqueductalno information on sizegreyLarry Cahill, a neurobiologist at the University of California, Irvine, has found evidence that, in some circumstances, people of different sexes use the same brain structures differently . Inbrain-imaging experiments, he asked groups of men and women to remember images they had been shown earlier . These images were chosen because they produce a strong emotional reaction . Both men and women consistently used the amygdala to complete the task. However, the men used the right side of the amygdala, while the women used the left side. What’s more, each group remembered different aspects of the image . The men remembered the gist of the situation whereas the women concentrated on the details . This suggests men and women process information from emotional events in very different ways .These studies are still in their early days, and there is much to be learned. Neurobiologists don’t really have a clear overall picture yet. Large pieces of the puzzle are missing, in part because imaging techniques are still rather basic . For researchers to see the brain in action , test subjects need to lie down inside a scanner or be wired up to a PET machine , which is very different from a real world situation . One possible solution is to attach a miniature MRI scanner to subjects’ heads. Then researchers would be able to see what happens as people go about their everyday lives .This area of research has some important uses. Working out exactly how brains are different could explain some mysteries , such as why men and women tend to have different mental health problems and why some drugs work well for one sex but have little effect on the other. Finding the reasons for this could lead to more effective treatments and better ways to prevent illness . This would be a very positive result.1. What is the passage is mainly about?A. the appeal of certain types of musicB. the possible effects of music on the brainC. the use of music in a learning environmentD. the importance of order in musical compositions2. Which of the following pairs of terms help to best explain the Mozart effect?A. left hemisphere and right hemisphereB. learning inside a classroom and learning outside a classroomC. music and intelligenceD. rhythm and beat3. Read the second paragraph of the passage. Which of the following sentences summarizes what the author is saying?A. Studies suggest that music affects both the body and mind.B. The Mozart sonata is especially effective in raising IQ scores.C. Researchers disagree about the impact of music on the brain.D. There are a number of theories about how music helps humans learn.4. Read the following sentence from paragraph 4. Which of the following details supports what the author is saying?“The simultaneous use of both sides of the brain is needed for the complete perception of music.”A. Music students score higher on tests and get better grades.B. The study of music is linked to intelligence.C. The Mozart sonata has a 60-beat-per-minute pattern.D. Pitch and intensity are perceived by different parts of the brain.1. How does music affect the brain?A. skimmingB. scanning2. What were the results of the study conducted in California?A. skimmingB. scanning3. Why was the Mozart sonata used in the study?A. skimmingB. scanning4. Is there only one theory about the connection between music and IQ?A. skimmingB. scanningf The scientist's research results (are completely different from) earlier research results, and now no one knows what to believe.a Falling down the stairs can cause terrible (feelings you have when your body hurts).d A person's (sex)—whether they are male or female—can be very important when giving them medical treatmentj There is (a lack of understanding) amongst some doctors and nurses about how to treat diseases of the brain.c Because we are making so little progress, I don't think it's (important or useful) to continue our research into this subject.b Many people (feel pain or are sick because of) mental health problems.h Recently, there have been (thorough and complete) changes in the way scientists understand the human brain.g People sweat to (control) their body heat.e These medicines (are right for) men, but they are not very good for women.i A child's (way of understanding) the world is not the same as an adult's.All of your answers are correct. Well done!1. The medicine suppressed the cancer's growth, and the diseasespread rapidly through the woman's body.false2. Depression is an illness that does not affect your emotions andthe way you feel.false3. After Jamila started taking the antidepressant, she felt muchhappier and was able to go back to work.true4. Circuits are paths through which electric currents travel,including circuits in the brain that block pain.true5. Broken bones, the flu, and diabetes are all example of mental healthproblems.falseM 1. Women seem to experience more pain than men because women and men use different circuits in the brain to block pain.D 2. Anne Murphy in the U.S. and Jeff Mogil in Canada did research on how men and women experience pain.M 3. Most pain killers are tested on men, but they have different effects on men and women.D 4. The painkiller Nalbuphine works well on women, but sometimes increases pain in men.D 5. It is very expensive to develop new drugs.M 6. With more research, better painkillers for women may be created.1. Suffer more often from depressionA. womenB. men2. Produce less serotoninA. womenB. men3. Respond better to antidepressants that work on serotoninA. womenB. men4. Are more often diagnosed with problems affecting brain systemsA. womenB. menOK. To sum up, there’s still a lot to learn. We’re just beginning to find out how pain control and mental health are different in men and women. One thing that is still astonishing is that so many researchers failed to include females in their studies. This is especially strange when it comes to pain research. Women are the most common sufferers of pain and yet most basic pain research is carried out only on males. In many areas , there seem to be more and more reports that the results of earlier research are actually only true for males, thus making the earlier researcherslook rather foolish. Anyway, what’s important is that resea rchers are now beginning to take women into account. We may well see medicines better suited to female physiology in the future. In a few decades’ time , women and men with the same illnesses could be treated in different ways. And this may apply to more than just the brain. So it’s an exciting field to explore—and one that could make a real difference to people’s lives.Another area where there are gender differences is mental health. Let’s take depression, for example. Women appear to suffer from depression twice as often as men, and their brains typically produce about half as much serotonin—a brain chemical linked to depression. Recently, Anna-Lena Nordström from the Karolinska Institute in Stockholm, Sweden, found that there seem to be significant differences in how male and female brains process serotonin. There are nofirm conclusions yet, but this is of special interest for two reasons . First,common antidepressants like Prozac work on serotonin. Second, there is evidence that women respond better to these common antidepressants than those that work on neurotransmitters other than serotonin.1. What is the speaker’s main point about learning?A. It is more difficult for some people than others.B. It affects only one hemisphere of the brain.C. It is connected to the physical brain.D. It cannot be scientifically measured.2. Which sentence explains one of the speaker’s main points?A. “This means that you learn details first, and then you piece them together tounderstand the main idea.”B. “We’re going to talk more about learning styles later, and about how we can use ourindividual learning styles to study effectively.”C. “And usually, one hemisphere is stronger than the other—at least in humans.”D. “The brain is divided into two hemispheres that process information in differentways.”3. What is the main point the professor wants listeners to know?A. Different types of people process information in different ways.B. Humans use the same reading strategy to understand texts.C. Certain ways of studying are more useful than others.D. Some types of study skills are not very effective.4. How does the professor support the main point?A. by explaining in detail how people readB. by linking study strategies to learning stylesC. by stressing the difficulty of some reading assignmentsD. by describing the physical structure1. Today we know there are big differences between men's and women's brains. In the past, we thought the differences were not as big.Today we know there are bigger differences between men's and women's brains than we thought in the past.2. Women often suffer from depression. Men don't suffer from depression as often.Women suffer from depression more often than men .3. With more research, we may be able to create effective painkillers for women. We don't have very effective painkillers for women now.With more research, we may be able to create painkillers that are more effective for women than painkillers we have today.4. There is evidence that women respond well to serotonin-based antidepressants. They don't respond well to antidepressants that don't work on serotonin.There is evidence that women respond better to serotonin-based antidepressants than to antidepressants that don't work on serotonin.5. Modern technology gives us detailed information about what is going on in the brain. The information from older methods of research was not as detailed.Modern technology gives us more detailed information about what is going on in the brain than older methods of research.6. The painkiller nalbuphine works well for women. It doesn't work well for men.The painkiller nalbuphine works better for women than for men .7. Parts of the frontal lobe are proportionately large in women. They aren't as large in men. Parts of the frontal lobe are proportionately larger in women than in men .8. Current brain research on males and females is useful. Past research on only males was not as usefulCurrent brain research on males and females is more useful than past research on only males.1. Both PET and fMRI scans make images of brain activity.A. trueB. false2. Before a PET scan, the person drinks a radioactive substance.A. trueB. false3. The radioactive substance collects in the active areas in the person's brain.A. trueB. false4. A PET scan can create a film showing brain activity.A. trueB. false5. The colors in a PET scan image show different amounts of mental activity.A. trueB. false6. More blood goes to areas where the brain is least active.A. trueB. false7. Responses to a magnetic field are different when blood oxygen levels are high.A. trueB. false8. An fMRI machine can take an image every one to four minutes.A. trueB. false1. Thesis: It's important to include women in medical research.Main Ideas:A. Animal brains are different from human brains.B. Men and women react differently to the same medication.C. Men's and women's brains are different.2. Thesis: More study is needed to understand the differences between male and female brains. Main Ideas:A. Most brain research in animals and humans is done only on male brains.B. Differences between men and women often result from social pressures, which causethem to behave in a certain way.C. Scientists have found some differences in the structure of male and female brains, butdon't know what those differences mean.3. Main Idea: Men and women react differently to the same medication.Supporting Details:A. Antidepressants like Prozac that work on serotonin levels are more effective in women.B. The frontal lobe and limbic cortex are bigger in women's brains.C. The painkiller nalbuphine is effective for women, but can increase pain in men.4. Main Idea:Men’s and women’s brains are different.Supporting Details:A. Men and women have different hormones which send different messages to the body.B. More boys than girls are diagnosed with brain system problems like autism andschizophrenia.C. The frontal lobe and limbic cortex are bigger in women's brains, while the parietalcortex and amygdala are bigger in men.5. Main Idea: Differences between men and women often result from social pressures, which cause them to behave in a certain way.Supporting Details:A. Girls are often expected to be quiet and obedient, while boys are allowed to be noisierand more adventuresome.B. Men are generally taller and have larger muscles than women.C. Studies have shown that teachers call on boys more often to give answers in class.。
