...Noise may be defined as any unwanted form of energy tending to interfere with the proper and easy reception and reproduction of signals. It may be subdivided according to type, source, effect, relation to the speaker, depending on circumstances. 1. External Noise. * Atmospheric Noise – consist of spurious radio components distributed a wide range of frequencies. Majority of these radio signals come from the natural sources of disturbance generally called static. * Extraterrestrial Noise * Solar Noise * Cosmic Noise * Industrial Noise – the intensity of noise made by humans easily outstrips that created by any other source, internal or external to the receiver. 2. Internal Noise * Thermal agitation noise – it is due to the rapid and random motion of molecules, atoms and electrons of which any such resistor is made up. Vn = 4kTδƒ R Example a. An amplifier operating the frequency rate from 18 to 20 MHz has a 10-kΩ input resistor. What is the rms noise voltage at the input to this amplifier if the ambient temperature is 27° C? Vn = 4kTδƒ R =4 x 1.38 x 3 x 2 x 10-11 = 1.82 x 10-5 = 18.2 μV * Shot noise – it is caused by random variations in the arrival of electrons at the output electrode of an amplifying device and thus as a randomly varying noise current superimposed on the output. 1.6 x 10-19 C in =2eip δf * Transmit Time Noise – if the time taken an electron to travel from the emitter to...
Words: 927 - Pages: 4
...Noise 1. Calculate for the noise power if the temperature of the conductor is 290 K, the bandwidth is 200kHz. PN=kTB PN=1.38x10-23290(200kHz) PN=8.004x10-16 W 2. With a resistance of 200k ohms, a bandwidth of 500khz and a temperature of 500 K calculate for the noise voltage. VN=4kTBR VN=41.38x10-23500(500k) VN=1.17x10-7 V 3. Given a noise power of 3000kW and a bandwidth of 2.5Mhz. Compute for the noise density No=PNB No=3000kW2.5Mhz No=1.2 WHz 4. Given a noise temperature of 350K calculate for the noise factor. Teq=ToF-1 F=TeqTo+1 F=350290+1 F=2.2 5. With a bandwidth of 450 hz and a current of 50mA. Compute for the shot noise. IN=2BIq IN=(2(450)(50mA)(1.6x10-19) IN=2.68 nA 6. Calculate for the Bandwidth if the noise power is 500kW and the temperature is 279K PN=kTB B=PNkT B=500kW1.38x10-23279 B=1.3x1026Hz 7. If the noise voltage is 20V and the resistance and temperature is 200 ohms and 273 K respectively, calculate for the bandwidth. VN=4kTBR B=Vn24TR B=2024200(273) B=1.83x10-3Hz 8. Given a signal voltage of 55V and a noise voltage of 35 V calculate for the signal-to-noise ratio in decibel form. SNdB=20logVsVN SNdB=20log5535 SNdB=3.93 dB 9. Given a signal power 60W and a noise power of 43W. Calculate for the signal-to-noise ratio in decibel form. SNdB=10logPsPN SNdB=10log6043 SNdB=1.45 dB 10. Given a signal power 80W and a noise power of 33W. Calculate for...
Words: 293 - Pages: 2
...Name: Tutor: Course: Date: Communication Quistion1 Noise is one of the obstacles to effective listening, and we define noise as any unwanted sound in any environment. Noise is a barrier to effective listening, and we can overcome this obstacle by one avoiding conversations in a noisy place secondly eliminating the source of the noise. Quistion2 Collaboration as a method of conflict management strategy refers to bringing together all the conflicting parties to find out the most appropriate solution to solve the problem. This method of conflict resolution is appropriate since it prevents further conflicts or advancing the level of conflict to a level that will be difficult to solve. Additionally collaboration is effective since it ensures all parties that were involved are satisfied in terms of the decision made to solve the conflict. Quistion3 Nonverbal communication can be used to pass information even without us knowing it, especially about our personality, thus none verbal communication can be used to enhance our self-confidence for example when giving a speech or talking to a single individual maintaining eye contact this shows that you have a strong personality and also a sense of responsibility in terms of believing in yourself. Quistion4 The first type of perceptual processing is sound this is the ability to distinguish sounds by detecting vibrations using our ears. Secondly, we will define speech, and we can say that speech is the process by which the sound...
Words: 592 - Pages: 3
...known as central auditory processing disorder (CAPD) is a hearing problem that affects about 5% of school-aged children. They may have a hard time tuning out background noise and find loud noises overwhelming. It may affect your ability to pinpoint a sound, tell which sound comes before another, distinguish similar sounds from one another (such as "seventy" and "seventeen") and enjoy music. DIAGNOSES: A pediatrician rules out other possibilities such as hearing loss related to an ear infection. A speech-language pathologist or school psychologist may also give your child tests that measure receptive language or listening comprehension skills as well as cognitive abilities. But only a trained audiologist can conduct the tests needed to make a diagnosis of APD. No matter how many symptoms of APD a child may have, only careful and accurate diagnostics can determine the underlying cause. It typically isn’t diagnosed until grade school, but there are some warning signs that can be detected in preschool. SIGNS AND SYMPTOMS: Auditory discrimination, auditory figure-ground discrimination, auditory memory, and auditory sequencing. Find it hard to follow spoken directions, especially multi-step instructions, saying “huh?” or “what?” often, easily distracted especially by background noise or loud and sudden noises, trouble with reading and spelling, they struggle with word math problems, trouble following conversation, poor musical ability, trouble learning songs or nursery rhymes...
Words: 330 - Pages: 2
...Impact of Noise on Recall of Advertisements Author(s): Bob T. Wu and Stephen J. Newell Source: Journal of Marketing Theory and Practice, Vol. 11, No. 2 (Spring, 2003), pp. 56-65 Published by: Taylor & Francis, Ltd. Stable URL: http://www.jstor.org/stable/40470111 Accessed: 30-11-2015 10:58 UTC REFERENCES Linked references are available on JSTOR for this article: http://www.jstor.org/stable/40470111?seq=1&cid=pdf-reference#references_tab_contents You may need to log in to JSTOR to access the linked references. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://www.jstor.org/page/ info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Taylor & Francis, Ltd. is collaborating with JSTOR to digitize, preserve and extend access to Journal of Marketing Theory and Practice. http://www.jstor.org This content downloaded from 27.251.83.10 on Mon, 30 Nov 2015 10:58:27 UTC All use subject to JSTOR Terms and Conditions THE IMPACT OF NOISE ON RECALL OF ADVERTISEMENTS Bob T. Wu BowlingGreenStateUniversity J. Stephen Newell Western MichiganUniversity that referred inmarketing to to and is a literature, hasbeenthe Noise,a barrier...
Words: 5776 - Pages: 24
...Silence… the most dreaded feared sound. The empty, hollow feeling that filled us all when we experience it. It’s drowning and knowing that there is nothing that you can do about it. The cause that had doomed our world, the utter destruction of silence. In today's school system music is being attacked left and right. Barely holding on by the skin of its teeth. Music one of the most important way of life that we have. It opens doors and opportunities to everyone that wants it, but it is being attacked and devalued in schools. However, music is beneficial it allows for a safe learning environment, takes the stress off of life and our heavy burdens, and it has academic benefits. In schools, there are a lot of different atmospheres that students can find themselves in and some are vicious and will destroy students values and beliefs. However, music classes allow for a safe social environment and teaches attributes such as responsibility, teamwork, discipline, and coordination. I study done by the H. Con. Res. 266, United States Senate found, Students who participate in school band or orchestra have the lowest levels of current and lifelong use of alcohol, tobacco, and illicit drugs among any group in our society, (“Music Makes a Difference.” Improving Lives Through Music, 2017). And in school, these are good attributes to have to help you impress future employers, to help get good work habits and get into a good college, and to keep your life going in a safe direction...
Words: 950 - Pages: 4
...running out of things to say so I am just typing whatever voice is in my head right now. Freaking people cannot drive. I am people are too loud, and don’t get me started on my cousin.. they don’t even trust their own kind.. family will be family. Ok ok ok you are right. It seems like no matter where you go, how much you shell out for rent, or how great the area is - there is almost always that one noisy, rude neighbor who is either completely oblivious of the world around them, or they're just flat out inconsiderate of others. While there are some noisy days that can be forgiven (New Year's Eve, for example) - frequent noise disturbance can become more than just a nuisance, and in some cases it can become an extremely serious issue. Tip #1 - Keep A Record! When having issues with a noisy neighbor - you should keep a record of dates and times when the noise was an issue - whether it was too loud, a minor annoyance or just plain overwhelming. While it's wishful thinking that the issue won't escalate to a true point of seriousness - it is better to be prepared and safe, rather than sorry later on. Tip #2 - Remain Polite At All Times! In some cases, your neighbor may simply be unaware that they're being too loud. Perhaps they simply have a heavy foot when walking across their floor (which may be your ceiling,) or they are unaware that their music is being heard through your shared wall (if they live above you, next to you, or below you.) If this is the first offense and...
Words: 1212 - Pages: 5
...advantages that it offers like high spectral efficiency, resistance to multipath fading and resistance to frequency selective fading. M oreover, it lends itself to simple channel equalization. Conventional single carrier systems do not provide such advantages and hence, OFDM would almost ubiquitously be used for high speed wireless data transmission. However, the main drawback of such systems over single carrier systems is that in the presence of noise, there is an increased computational complexity at the receiver end to decode the data. In this paper, a low complexity detection algorithm is proposed for OFDM systems. M aximum likelihood detection is taken as the baseline detection algorithm and the proposed algorithm is compared with M L detection algorithm. Comparison results are plotted and conclusions are drawn. Reference [4] provides an iterative detection scheme for OFDM in presence of impulsive noise while [5] proposes an impulsive noise mitigation scheme for over-sampled OFDM systems. Performance and design of impulse noise detector for OFDM systems is provided in [6]. Reference [7] proposes an MM SE detection...
Words: 2583 - Pages: 11
...frequency)300-3000MHz, and SHF (super high frequency)3-30GHz? 7. A microwave transmitter typically requires a +8dBm audio level to drive the input fully. If a +10 dBm level is measured, what is the actual voltage level measured? Assume a 600Ω system. (2.45V) Hint: Use this equation and solve it for V2 10 dBm = 20 · log10 (V2/0.77459) 9. Convert the following power to their dBm equivalents: (a) p = 1 W = 30.0000dBm (b) p = 0.001 W = 0.00000dBm (c) p = 0.0001W = -10.0000dBm (d) p = 25 μW = dBm Use this formula: dBm = 10 · log10 [P2/(10-3)] 15. Define electrical noise and explain why it is so troublesome to a communications receiver. Noise is a random fluctuation in an electrical signal and is an error or undesired random disturbance of a useful information. 16. Explain the difference between internal and external noise. Internal noise is that which a system generates on its own and external noise comes from an external source. 23. Calculate the S/N...
Words: 703 - Pages: 3
...Effects of Population Density and Noise Population density is a term described as the ratio of people and organisms in relation to the size of the area they inhabit. This ratio is derived by taking the number of people in the given area and diving the number by the area occupied. As of the 2010 Census, there were 308,745,538 people in the United States. (U.S. Census Bureau, 2013). This means the population density is on average 87.4 people per square mile in the United States. (U.S. Census Bureau, 2013). Some states, like California and Florida have a density of 200 people per square mile. These figures are a prime example of crowding in many places. As population density increases, the noise from the population is going to increase especially in crowded areas. As people are moving into smaller and more confined areas, the ability to maintain their privacy and a sense of territoriality will change and be forced to adapt. In order to understand how population density truly affects people, the concepts of noise, privacy, territoriality, and personal space must be acknowledged and applied to the subject of populations. Territoriality, Privacy, and Personal Space Individuals will experience proximity or closeness with every other person in the world at one time or another. Proxemics is the actual term used when describing the person-environmental associations and covers the terms of territoriality, crowding, and personal space. Territoriality The term territoriality...
Words: 1429 - Pages: 6
...Financial Time Series Analysis Jiajing Sun University of Chinese Academy of Sciences 22 September 2013 J. Sun (UCAS) ARMA(1) 22 September 2013 1 / 23 Review As pointed out in the last week, the objective of studying …nancial time series analysis is to predict future values of some …nancial variable. This objective is achieved by following methodology based on: 1 2 3 4 Model Speci…cation; Model Estimation; Model Validation; Forecasting (or prediction) Note: The model to be used for forecasting is in fact estimated from history, i.e. data from the past is used to make probabilistic statements about future values. J. Sun (UCAS) ARMA(1) 22 September 2013 2 / 23 Stationarity Historical values are used to identify the dynamic properties of the time series (relationship between current and past values) and these are used to forecast the future. A critical assumption behind the methodology that we develop …rst in this course is that such dynamics do not change over time. In a heuristic sense, we require the future to be like the past in a probabilistic sense. This requirement is formalized by the concept of stationarity. J. Sun (UCAS) ARMA(1) 22 September 2013 3 / 23 Stationarity Strict Stationarity A time series Y is strictly stationary if its probabilistic distribution does not change over time. That is, for any k, the joint distribution of (Yt , Yt 1 , ..., Yt k +1 ) does not depend on t. In other words, the joint...
Words: 2147 - Pages: 9
...Rollin Luis NETW320 Professor Antoniou Week 2 HW assignment Silent suppression is a technique used to improve bandwidth utilization of voice circuits. Through silence suppression, a mechanism senses periods of inactivity in a voice conversation and simply ceases sending data associated. Silent suppression can be enabled to monitor signals for voice activity so that when silence is detected for a specified amount of time, the application informs the Packet Voice Protocol and prevents the encoder output from being transported across the network. To help understand silence suppression technology, consider this example: Some people talk all the time. Even they have to take a breath and they sometimes listen and are quiet. On a phone call, it is quite common that there is silence in one direction of the call while there is speech carried in the other direction. The public switched telephone network does not take advantage of this condition. The PSTN opens up a path in both directions, between the speakers, and allocates 100% of the path capacity to the call, even when there is silence. Silent suppression is the application of this IP network principle to VoIP calls. When there is silence, you don't send voice packets full of silence. Silence suppression can save bandwidth, especially on IP trunks. The savings can be 40% to 50%. The packet-sending phone or gateway implements the VAD function in the codec. When you think of silent suppression think of it as speech door. It opens...
Words: 655 - Pages: 3
...Stochastic Resonance of FHN Model 1 Introduction Deterministic, nonlinear systems with excitable dynamics, e.g. the FitzHugh Nagumo (FHN) Model, undergo bifurcation from stable focus to limit cycle on tuning the system parameter. However, addition of uncorrelated noise to the system can kick the system to the limit cycle region, thus exhibiting spiking behaviour if the parameter is hold on the fixed point side. Thus the system exhibits intermittent cyclic behaviour, manifesting as spikes in the dynamical variable. It is interenting to note that at an optimal value of noise, the seemingly irregular behaviour of the spikes becomes strangely regular. The interspike interval τp becomes almost regular and the Normal√ p ized Variance of the interspike interval, defined by VN = exhibits τp a minima as a function of noise strength (D). The phenomenon is termed as Coherence Resonance. Coherence Resonance is a system generated response to the noise. However, there is another form of resonance that is found at lower level of noise in response to a subthreshold signal, known as Stochastic Resonance. Subthreshold signals that are in general undetectable can often be detected in presence of noise. There is an optimal level of noise at which such information transmission is optimal. Stochastic resonance has been investigated in many physical, chemical and biological systems. It can be utilised for enhancing signal detection and information transfer. SR has been obversed for subthreshold input...
Words: 744 - Pages: 3
...11/5/2004 Noise Margins 1/12 Noise Margins The transfer function of a digital inverter will typically look something like this: vO V+ d vO = −1 dv I Transition Region d vO = −1 dv I vO = f (vI ) I III II V+ vI Note that there are essentially three regions to this curve: I. The region where vI is relatively low, so that the output voltage vO is high. II. The region where vI is relatively high, so that the output voltage vO is low. III. The transition region, where the input/output voltage is in an indeterminate state (i.e, an ambiguous region between high and low. Jim Stiles The Univ. of Kansas Dept. of EECS 11/5/2004 Noise Margins 2/12 Note that the transition region is rather arbitrarily defined by the points on the transfer function where the magnitude of the slope is greater than one (i.e., where d vO dv I > 1.0 ). Although this transfer function looks rather simple, there are actually several parameters that we use to characterize this transfer function—and thus characterize the digital inverter as well! 1. First of all, let’s consider the case when vI=0. The output of the digital inverter in this condition is defined as VOH (i.e., OH “output high”), i.e.: VOH vO when v I = 0 Thus, VOH is essentially the “ideal” inverter high output, as it is the output voltage when the inverter input is at its ideal low input value vI=0. Typically, VOH is a value just slightly less than supply voltage V+. 2. Now, let’s consider the...
Words: 1599 - Pages: 7
...My family is deaf. All my aunts and uncles are deaf. We like to get together and have a good time while making a lot of noise, but it doesn't mean anything to us. My husband is deaf and we had a daughter who was born hearing. We were surprised that she was born hearing. That meant that we had to learn about how sound is interpreted by hearing people. I remember a funny story that I'd like to tell you now. One day, my hearing daughter brought her hearing friends over. They were all sitting in the living room while I was in the kitchen doing dishes and putting them away. My daughter came to me concerned and asked me “Mom, are you okay?” I looked at her confused and said “Yeah, I'm okay.” She said “Well, are you mad?” I said “No, I'm not mad.” She asked “Are you not feeling well?”. I said “No, I feel fine. Why do you ask?” My daughter said that they thought I was mad because I was making loud noises in the kitchen. I said “What do you mean?” She said “You were closing the drawers very hard and putting the dishes away very loudly. My friends said you were angry at me for not helping you clean.” I said “Oh, okay.” The next time she brought her friends over, I told myself “Okay, I got to be careful putting things away.” I cleaned everything very quietly and put everything away carefully, very different from my usual way of doing things in the past. When I was finished doing that, I was exhausted. My daughter came in and asked “Are you okay? You are being very quiet.” I...
Words: 324 - Pages: 2
