# 2011 Intensity - 1 INTENSITY OF SOUND. To understand the concept of sound intensity and how it is measured.

Save this PDF as:

Size: px
Start display at page:

Download "2011 Intensity - 1 INTENSITY OF SOUND. To understand the concept of sound intensity and how it is measured."

## Transcription

1 2011 Intensity - 1 INTENSITY OF SOUND The objectives of this experiment are: To understand the concept of sound intensity and how it is measured. To learn how to operate a Sound Level Meter APPARATUS: Radio Shack Sound Level Meter, meterstick, function generator in FFTSCOPE, headphones. INTRODUCTION Sound energy is conveyed to our ears (or instruments) by means of a wave motion through some medium (gas, liquid, or solid). At any given point in the medium the energy content of the wave disturbance varies as the square of the amplitude of the wave motion. That is, if the amplitude of the oscillation is doubled the energy of the wave motion is quadrupled. The common method in gauging this energy transport is to measure the rate at which energy is passing a certain point. This concept involves sound intensity. Consider an area that is normal to the direction of the sound waves. If the area is a unit, namely one square meter, the quantity of sound energy expressed in Joules that passes through the unit area in one second defines the sound intensity. Recall the time rate of energy transfer is called "power". Thus, sound intensity is the power per square meter. The common unit of power is the watt ( 1 W = 1 Joules/s). Normally, sound intensity is measured as a relative ratio to some standard intensity, I o. The response of the human ear to sound waves closely follows a logarithmic function of the form R k logi, where R is the response to a sound that has an intensity of I, and k is a constant of proportionality. Thus, we define the relative sound intensity level as SL(dB) 10log I Io The unit of SL is called the decibel (abbreviated db). I is the intensity of the sound expressed in watts per meter and Io is the reference intensity defined to be W/m 2. This value of I o is the threshold (minimum sound intensity) of hearing at 1 khz for a young person under the best circumstances. Notice that I/Io is a unitless ratio; the intensities need only to be expressed in the same units, not necessarily W/m 2. Another logarithmic measure of loudness is the sound pressure level defined as

2 2011 Intensity - 2 Where p is the pressure amplitude and is the reference pressure variation. The units of the sound pressure level are also decibels (db). Though typically indistinguishable from the sound intensity level, it is the sound pressure level which is measured on most common devices for determining loudness (e.g. the sound level meter discussed below). The sound pressure level is also written SPL for short. Examples: 1. If we measured a sound intensity to be 560 greater that the threshold reference, what would be the sound intensity level expressed in db? SL(dB) 10log( ) 10log(560) 27.5dB 2. The threshold of pain is about 120 db. How many times greater in intensity (in W/m 2 ) is this? SL(dB) 10log( I I ) o log( I ) I I o I 1watt / 2 m Notice that the approximate threshold of pain is a factor of (that's a trillion!) greater than the threshold of hearing. The Sound Level Meter Figure 1 The instrument we will use for measuring sound levels is a Sound Level Meter (SLM) shown in Figure 1. * It consists of a microphone to detect the sound and convert it to a voltage, an amplifier to increase this * Adapted from the owner's manual of the Radio Shack Sound Level Meter, 1985 Tandy Corporation.

3 2011 Intensity - 3 voltage, weighting circuitry which is explained below, and a meter to display the sound level in db. The SLM has three switches to control its operation: Range Selector: The rotary switch is used to select one of seven sound level ranges, each spanning 16 db. Numbers of RANGE switch refer to the center-points of the seven ranges. The needle indicator shows the actual sound level as a displacement from the center-point. Examples: Suppose RANGE is set to 80, and meter scale reads -3. Actual sound level is 80-3 = 77 db. If the meter scale reads 0 (same RANGE setting), the actual sound level is = 80 db. Response Selector: In FAST position, the meter will react quickly to the change in the sound level, giving you an indication of peak sound levels present in the environment. On SLOW position, the meter is damped and indicates an averaged valued for the sound level. The effect of bursts of sounds (intensity peaks) is minimized in the SLOW response. Weighting Selector: The frequency response of the Sound Level Meter for each weighting characteristic is shown below. The C-weighting curve is nearly uniform over the frequency range from 32-10,000 Hz, thus giving an indication of overall sound level. The A-weighting characteristic responds primarily to frequency ranges in the ,000 Hz range, which is the area of the greatest sensitivity of the human ear. Taking Accurate Measurements: Select the RESPONSE and WEIGHTING. If the sound source consists of short bursts, or if you are interested in peak values only, set the RESPONSE to FAST. To measure average sound levels, use the SLOW setting. Select A-weighting for noise level determinations, and C-level for measuring sound levels which stay at 90 db or above, or for which you wish to eliminate the ear's weighting

4 2011 Intensity - 4 factor. The A-weighting gives a better indication of apparent loudness at low frequencies because its frequency response is similar to that of the human ear. The C-weighting may be slightly more accurate in this respect at frequencies above 1 khz. Start with the HIGHEST RANGE setting (120 db) and work downward until there is significant deflection of the needle. For GREATEST ACCURACY, always use the lower of any two possible settings. Example: If the RANGE is set to 80 db and the meter reads around -5, reset the RANGE to 70 db and the meter will read +5, for an actual sound level of 75 db. In addition to the older model SLMs described above, your lab may also use newer devices with digital display of the sound pressure level. Their operations are analogous. The Sone The decibel is a measure of the sound level which does not include the human perception of loudness. The SONE is a unit that measures the perceived loudness of a sound. It is defined in terms of decibels and frequency: 1 Sone = 40 1 khz = the loudness of a 1 khz sound with an SPL of 40 db. At 1 khz, the loudness in Sones can be related to the SPL in decibels by the following formula: Loudness (Sones) = 2 (SPL in db - 40)/10 In general though, the apparent loudness of a sound depends on its frequency. As mentioned, the ear is less sensitive to low frequency sounds. Therefore a unit called the phon is defined so that it will have the same value at low or high frequencies if the sound at these different frequencies produces the same subjective impression of loudness. The curves of equal loudness level ( ) pictured left correspond to a certain loudness in phons. The results of two different studies are pictured in red and blue.

5 2011 Intensity - 5 The general equation for loudness in Sones is therefore S = Since the loudness level in phons can be estimated for a given frequency and SPL with the Fletcher-Munson curves or the more modern ISO convention (both pictured above), the loudness in Sones can be readily determined. Notice that it takes a sound of greater intensity and pressure to achieve the same loudness at lower frequencies. Example: What is the loudness in Sones of a 50 db sound at 1 khz? Loudness (Sones) = 2 (50-40)/10 = 2 1 = 2 Sones are useful units in that 2 Sones are supposed to be twice as loud as 1 Sone and 4 Sones are 4 times as loud as 1 Sone. However, the ear has no meterstick to judge loudness very accurately. The interpretation of the data from the ear is done by the brain, not by a more exact electronic meter. In fact the convention above that a ten-fold increase in SPL is required for a doubling of apparent loudness at 1 khz has been called into question. Some researchers believe that a doubling in loudness is effected by a 6 db increase in SPL. Thus, the seemingly universal perception of a similarity in sound upon doubling the frequency of a tone (i.e. the octave in music) doesn t necessarily have an exact counterpart where loudness is concerned. In part 2.A of this experiment, we will try to find out how accurate the Sone scale is.

6 2011 Intensity - 6 INTENSITY OF SOUND LAB REPORT FORM NAME: DATE: PARTNER(S): Procedure Part One: A. Familiarize yourself with the operation of the Sound Level Meter by measuring the background sound level of the lab room. Turn on the meter by setting the range dial to 120 db. Set the response of the meter to SLOW. First measure the background sound level of the room by choosing C weighting. Rotate the range knob down through the ranges until the meter moves. Then measure the background sound level using the A weighting of the meter. If the value is too low for the sound level meter to read, assume that it is 60 db. Background Sound Level with C weighting = Background Sound Level with A weighting = Calculate the difference between the SPL measured with the C and A weighting and use the graph (Figure 2) to estimate the average frequency of the background sound. B. Measure the sound level of a person talking from various distances. You will want to use FAST response to get peak sound levels. This does not have to be quantitatively accurate. Use the meter stick to measure the distances. Distance ( ) Sound Level (db)

8 2011 Intensity - 8 Loudness (Sones) Theoretical Sound Level (db) Measured Sound Level (db) Deviation (%) B. Now set the function generator to 100 Hz sine wave. Set the Sound Level Meter to "A" weighting. Now adjust the loudness from the headphones to 60 db. Listen to the sound. Keeping the speaker volume the same, measure the sound level for 1 k Hz. Listen again. Which signal sounds louder? Why? If your sound level meter will not register 60 db (i.e. it is sub-threshold), you may use 70 or 80 db instead. Enter your measured values in the table on the following page. Try repeating this for "C" weighting. Is there any difference between the sounds at the two frequencies? Any difference from the A weighting? Explain.

9 2011 Intensity - 9 Tabulate your results. Determine the loudness in phons by using the chart on pg.4 (red lines) with the C weighted values. Remembering that the A weighting already provides a good estimate of apparent loudness, compare the values for loudness level in phons as read from the chart and as measured with the A weighting. Comment below. From the A weighted value, compute the loudness in sones. Enter it in the final column. Signal (Hz) Sound Level "A" Weighting db(a) Sound Level "C" Weighting db(c) Approximate Loudness (Phons) Sones - "A" Weighting (Sones)

### Acoustic Terms, Definitions and General Information

Acoustic Terms, Definitions and General Information Authored by: Daniel Ziobroski Acoustic Engineer Environmental and Acoustic Engineering GE Energy Charles Powers Program Manager Environmental and Acoustic

### Noise. CIH Review PDC March 2012

Noise CIH Review PDC March 2012 Learning Objectives Understand the concept of the decibel, decibel determination, decibel addition, and weighting Know the characteristics of frequency that are relevant

### FREQUENCY RESPONSE OF AN AUDIO AMPLIFIER

2014 Amplifier - 1 FREQUENCY RESPONSE OF AN AUDIO AMPLIFIER The objectives of this experiment are: To understand the concept of HI-FI audio equipment To generate a frequency response curve for an audio

### Sound Pressure Measurement

Objectives: Sound Pressure Measurement 1. Become familiar with hardware and techniques to measure sound pressure 2. Measure the sound level of various sizes of fan modules 3. Calculate the signal-to-noise

### Copyright 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.

Chapter 20. Traveling Waves You may not realize it, but you are surrounded by waves. The waviness of a water wave is readily apparent, from the ripples on a pond to ocean waves large enough to surf. It

### Trigonometric functions and sound

Trigonometric functions and sound The sounds we hear are caused by vibrations that send pressure waves through the air. Our ears respond to these pressure waves and signal the brain about their amplitude

### physics 1/12/2016 Chapter 20 Lecture Chapter 20 Traveling Waves

Chapter 20 Lecture physics FOR SCIENTISTS AND ENGINEERS a strategic approach THIRD EDITION randall d. knight Chapter 20 Traveling Waves Chapter Goal: To learn the basic properties of traveling waves. Slide

### Part II: What s your db IQ?

Page 1 of 5 Hello, and welcome to the long awaited Part Two of What s your db IQ? I would sincerely like to thank all who have written me since the publication of Part One to tell me that you found it

### MICROPHONE SPECIFICATIONS EXPLAINED

Application Note AN-1112 MICROPHONE SPECIFICATIONS EXPLAINED INTRODUCTION A MEMS microphone IC is unique among InvenSense, Inc., products in that its input is an acoustic pressure wave. For this reason,

### 15160 Resonance Tube Set

CONTENTS Included o (1) Long Tube o (1) Short Tube o (1) Styrene Plug o (1) Tuning Fork, 512 Hz o (1) Rubber Mat, 3 diameter Suggested Accessories o Tuning Forks (other frequencies) o (1) Oscilloscope

### Tuning Subwoofers - Calibrating Subwoofers

Tuning Subwoofers - Calibrating Subwoofers WHY The purpose of a subwoofer is to fill in the bottom octaves below the capabilities of the mains speakers. There are many reasons to use a subwoofer to do

### Decibel Table Loudness Comparison Chart

Deutsche Version Decibel Table Loudness Comparison Chart Table of Sound Levels (db Scale) and the corresponding Units of Sound Pressure and Sound Intensity (Examples) To get a feeling for decibels, look

### Noise. Patrick N. Breysse, PhD, CIH Peter S.J. Lees, PhD, CIH. Johns Hopkins University

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike License. Your use of this material constitutes acceptance of that license and the conditions of use of materials on this

### Relationship between Sound Pressure and Sound Power Levels

Relationship between Sound Pressure and Sound Power Levels 4 W. T. W. CORY Chairman of the Eurovent WG 1 Fans If we wish to know the sound power transmitted through a fan and ducting system, it is preferable

### A Tutorial on the Decibel

A Tutorial on the Decibel This tutorial combines information from several authors, including Bob DeVarney, W1ICW; Walter Bahnzaf, WB1ANE; and Ward Silver, NØAX Decibels are part of many questions in the

### Estimation of Loudness by Zwicker's Method

Estimation of Loudness by Zwicker's Method Loudness is one category in the list of human perceptions of sound. There are many methods of estimating Loudness using objective measurements. No method is perfect.

### Basic Concepts of Sound. Contents: Definitions db Conversion Sound Fields db ± db

Basic Concepts of Sound Contents: Definitions db Conversion Sound Fields db ± db BA 7666-11, 1 Abstract This lecture introduces sound and sound measurements by describing sound pressure, sound level and

### Electrical Resonance

Electrical Resonance (R-L-C series circuit) APPARATUS 1. R-L-C Circuit board 2. Signal generator 3. Oscilloscope Tektronix TDS1002 with two sets of leads (see Introduction to the Oscilloscope ) INTRODUCTION

### INTERFERENCE OF SOUND WAVES

2011 Interference - 1 INTERFERENCE OF SOUND WAVES The objectives of this experiment are: To measure the wavelength, frequency, and propagation speed of ultrasonic sound waves. To observe interference phenomena

### A PRACTICAL GUIDE TO db CALCULATIONS

A PRACTICAL GUIDE TO db CALCULATIONS This is a practical guide to doing db (decibel) calculations, covering most common audio situations. You see db numbers all the time in audio. You may understand that

### The moment of inertia of a rod rotating about its centre is given by:

Pendulum Physics 161 Introduction This experiment is designed to study the motion of a pendulum consisting of a rod and a mass attached to it. The period of the pendulum will be measured using three different

### The Oscilloscope, the Signal Generator and Your Filter s Test Setup SGM 5/29/2013

The Oscilloscope, the Signal Generator and Your Filter s Test Setup SGM 5/29/2013 1. Oscilloscope A multimeter is an appropriate device to measure DC voltages, however, when a signal alternates at relatively

### Fundamentals Series Analog vs. Digital. Polycom, Inc. All rights reserved.

Fundamentals Series Analog vs. Digital Polycom, Inc. All rights reserved. Fundamentals Series Signals H.323 Analog vs. Digital SIP Defining Quality Standards Network Communication I Network Communication

### Chapter 11. Waves & Sound

Chapter 11 Waves & Sound 11.2 Periodic Waves In the drawing, one cycle is shaded in color. The amplitude A is the maximum excursion of a particle of the medium from the particles undisturbed position.

### Resonance and the Speed of Sound

Name: Partner(s): Date: Resonance and the Speed of Sound 1. Purpose Sound is a common type of mechanical wave that can be heard but not seen. In today s lab, you will investigate the nature of sound waves

### STANDING WAVES & ACOUSTIC RESONANCE

REFERENCES & ACOUSTIC RESONANCE R.H. Randall, An Introduction to Acoustics, (Addison-Wesley, 1951), Sect. 7-1, 7-. A.B. Wood, A Textbook of Sound, (Bell & Sons, 1944), pp.179 et seq. Berkeley Physics Course,

### 5-Minute Refresher: SOUND AND HEARING

5-Minute Refresher: SOUND AND HEARING Sound Key Ideas Sound is a type of energy that involves the vibration of molecules in a medium, such as air or water. Sound is transmitted through a medium as a pressure

### AM TRANSMITTERS & RECEIVERS

Reading 30 Ron Bertrand VK2DQ http://www.radioelectronicschool.com AM TRANSMITTERS & RECEIVERS Revision: our definition of amplitude modulation. Amplitude modulation is when the modulating audio is combined

### Lab 1: The Digital Oscilloscope

PHYSICS 220 Physical Electronics Lab 1: The Digital Oscilloscope Object: To become familiar with the oscilloscope, a ubiquitous instrument for observing and measuring electronic signals. Apparatus: Tektronix

### Yerkes Summer Institute 2002

Before we begin our investigations into radio waves you should review the following material on your trip up to Yerkes. For some of you this will be a refresher, but others may want to spend more time

### Name Date Day/Time of Lab Partner(s) Lab TA

Name Date Day/Time of Lab Partner(s) Lab TA Objectives LAB 7: AC CIRCUITS To understand the behavior of resistors, capacitors, and inductors in AC Circuits To understand the physical basis of frequency-dependent

### Spectrum Level and Band Level

Spectrum Level and Band Level ntensity, ntensity Level, and ntensity Spectrum Level As a review, earlier we talked about the intensity of a sound wave. We related the intensity of a sound wave to the acoustic

### The Sonometer The Resonant String and Timbre Change after plucking

The Sonometer The Resonant String and Timbre Change after plucking EQUIPMENT Pasco sonometers (pick up 5 from teaching lab) and 5 kits to go with them BK Precision function generators and Tenma oscilloscopes

### Hearing Sound. The Human Auditory System. The Outer Ear. Music 170: The Ear

Hearing Sound Music 170: The Ear Tamara Smyth, trsmyth@ucsd.edu Department of Music, University of California, San Diego (UCSD) December 1, 2015 Sound interpretation in the auditory system is done by 1.

### CBS RECORDS PROFESSIONAL SERIES CBS RECORDS CD-1 STANDARD TEST DISC

CBS RECORDS PROFESSIONAL SERIES CBS RECORDS CD-1 STANDARD TEST DISC 1. INTRODUCTION The CBS Records CD-1 Test Disc is a highly accurate signal source specifically designed for those interested in making

### Hearing Conservation Program

Hearing Conservation Program Environmental Health & Safety 122 Grand Ave. Ct. Ph. 319-335-8501 Revised 8/2015 TABLE OF CONTENTS 1.0 Purpose... 2 2.0 Scope... 2 3.0 Definitions... 2 4.0 Roles and Responsibilities...

### Data Communications Prof. Ajit Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture # 03 Data and Signal

(Refer Slide Time: 00:01:23) Data Communications Prof. Ajit Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture # 03 Data and Signal Hello viewers welcome

### LAB 9 Waves and Resonance

Cabrillo College Physics l0l Name LAB 9 Waves and Resonance Read Hewitt Chapter 19 What to learn and explore Almost all of the information that we receive from our environment comes to us in the form of

### Computer Networks and Internets, 5e Chapter 6 Information Sources and Signals. Introduction

Computer Networks and Internets, 5e Chapter 6 Information Sources and Signals Modified from the lecture slides of Lami Kaya (LKaya@ieee.org) for use CECS 474, Fall 2008. 2009 Pearson Education Inc., Upper

### The Effects of Ultrasonic Sound Generated by Ultrasonic Cleaning Systems on Human Hearing and Physiology

The Effects of Ultrasonic Sound Generated by Ultrasonic Cleaning Systems on Human Hearing and Physiology Questions about the effects of ultrasonic energy on hearing and other human physiology arise from

### PURE TONE AUDIOMETER

PURE TONE AUDIOMETER V. Vencovský, F. Rund Department of Radioelectronics, Faculty of Electrical Engineering, Czech Technical University in Prague, Czech Republic Abstract Estimation of pure tone hearing

### TV hearing aid BL-8008A BL-8008B. Manual

TV hearing aid BL-8008A BL-8008B Manual A. Product instruction 1. What is TV hearing aid 2. Theory 3. Features 4. Functions 4.1 TV hearing aid function 4.2 Normal hearing aid function 4.3 Wired hearing

### Schindler 3300 / Schindler 5300 Information on noise and vibration.

Schindler 3300 / Schindler 5300. Content Introduction 1. Ride quality Jerk Car acceleration Vertical car vibration Lateral car vibration Sound in the car 2. Sound basics 3. Vibration basics 4. Structure-borne

### E. K. A. ADVANCED PHYSICS LABORATORY PHYSICS 3081, 4051 NUCLEAR MAGNETIC RESONANCE

E. K. A. ADVANCED PHYSICS LABORATORY PHYSICS 3081, 4051 NUCLEAR MAGNETIC RESONANCE References for Nuclear Magnetic Resonance 1. Slichter, Principles of Magnetic Resonance, Harper and Row, 1963. chapter

### The RC Circuit. Pre-lab questions. Introduction. The RC Circuit

The RC Circuit Pre-lab questions 1. What is the meaning of the time constant, RC? 2. Show that RC has units of time. 3. Why isn t the time constant defined to be the time it takes the capacitor to become

### AP1 Waves. (A) frequency (B) wavelength (C) speed (D) intensity. Answer: (A) and (D) frequency and intensity.

1. A fire truck is moving at a fairly high speed, with its siren emitting sound at a specific pitch. As the fire truck recedes from you which of the following characteristics of the sound wave from the

### Mathematical Harmonies Mark Petersen

1 Mathematical Harmonies Mark Petersen What is music? When you hear a flutist, a signal is sent from her fingers to your ears. As the flute is played, it vibrates. The vibrations travel through the air

### Audible Alarm Basics Everything you wanted to know, but were afraid to ask by Dan O Brien, Sales Engineer, Mallory Sonalert Products, Inc.

Audible Alarm Basics Everything you wanted to know, but were afraid to ask by Dan O Brien, Sales Engineer, Mallory Sonalert Products, Inc. From smoke detectors to automobiles, audible alarms (also known

### THE MYTHICAL X CURVE

THE MYTHICAL X CURVE The curve that s not a curve By John F. Allen Of all the topics I have covered over the last 21 years, one of the most important - sometimes controversial - is the subject of cinema

### STEREO POWER AMPLIFIER MODEL: WPA-600 PRO OWNER S MANUAL

STEREO POWER AMPLIFIER MODEL: WPA-600 PRO OWNER S MANUAL CAUTION: Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.

### Chapter 6. Single Sideband Transmitter Tests and Measurements

Chapter 6 Single Sideband Transmitter Tests and Measurements This chapter deals with the basic tests and measurements that can be used to evaluate the performance of single sideband suppressed carrier

### General Physics (PHY 2130)

General Physics (PHY 2130) Lecture 28 Waves standing waves Sound definitions standing sound waves and instruments Doppler s effect http://www.physics.wayne.edu/~apetrov/phy2130/ Lightning Review Last lecture:

### Resonance in a Closed End Pipe

Experiment 12 Resonance in a Closed End Pipe 12.1 Objectives Determine the relationship between frequency and wavelength for sound waves. Verify the relationship between the frequency of the sound, the

### Experiment 4 Analysis by Gas Chromatography

Experiment 4 Analysis by Gas Chromatography In this experiment we will study the method of gas chromatography. Gas chromatography (GC) is one of the most important analytical tools that the chemist has.

### Hearing. 1 Introduction. 1.1 Auditory system. 1.2 Psychoacoustics

Hearing Sources: Rossing. (1990). The science of sound. Chapters 5 7. Karjalainen. (1999). Kommunikaatioakustiikka. Moore. (1997). An introduction to the psychology of hearing. Contents: 1. Introduction

### Lecture 1-8: Audio Recording Systems

Lecture 1-8: Audio Recording Systems Overview 1. Why do we need to record speech? We need audio recordings of speech for a number of reasons: for off-line analysis, so that we can listen to and transcribe

### Sound Attenuation INTRODUCTION

INTRODUCTION In the broadest sense, a sound wave is any disturbance that is propagated in an elastic medium, which may be a gas, a liquid, or a solid. Noise is defined as any unwanted sound perceived by

### Standing Waves Physics Lab I

Standing Waves Physics Lab I Objective In this series of experiments, the resonance conditions for standing waves on a string will be tested experimentally. Equipment List PASCO SF-9324 Variable Frequency

### Part Number Structure ZT 028 L D CT R 15

Product Application Guide- 22mm Industrial Alarms with LED Lights Part Number Structure ZT 028 L D CT R 15 Series: ZT = 22mm with LED Maximum Voltage: 016 = 9-16; 028 = 16-28; 120 = 48-120 Sound Level:

### Sound absorption and acoustic surface impedance

Sound absorption and acoustic surface impedance CHRISTER HEED SD2165 Stockholm October 2008 Marcus Wallenberg Laboratoriet för Ljud- och Vibrationsforskning Sound absorption and acoustic surface impedance

### Convention Paper Presented at the 112th Convention 2002 May 10 13 Munich, Germany

Audio Engineering Society Convention Paper Presented at the 112th Convention 2002 May 10 13 Munich, Germany This convention paper has been reproduced from the author's advance manuscript, without editing,

### 1. SAFETY INFORMATION

RS-232 Sound Level Meter 72-860A INSTRUCTION MANUAL www.tenma.com 1. SAFETY INFORMATION Read the following safety information carefully before attempting to operate or service the meter. Use the meter

### Lecture 1-6: Noise and Filters

Lecture 1-6: Noise and Filters Overview 1. Periodic and Aperiodic Signals Review: by periodic signals, we mean signals that have a waveform shape that repeats. The time taken for the waveform to repeat

### bx_meter manual Peak, RMS and Dynamic Range Metering with L/R and M/S modes 2011 by Brainworx Music & Media GmbH

Peak, RMS and Dynamic Range Metering with L/R and M/S modes 2011 by Brainworx Music & Media GmbH bx_ meter manual This is where we develop our products... the Brainworx Studio VISIT brainrox.com / brainrox.de

### Direct and Reflected: Understanding the Truth with Y-S 3

Direct and Reflected: Understanding the Truth with Y-S 3 -Speaker System Design Guide- December 2008 2008 Yamaha Corporation 1 Introduction Y-S 3 is a speaker system design software application. It is

### Experiment V: The AC Circuit, Impedance, and Applications to High and Low Pass Filters

Experiment : The AC Circuit, Impedance, and Applications to High and Low Pass Filters I. eferences Halliday, esnick and Krane, Physics, ol. 2, 4th Ed., Chapters 33 Purcell, Electricity and Magnetism, Chapter

### Direct Digital Amplification (DDX ) The Evolution of Digital Amplification

Direct Digital Amplification (DDX ) The Evolution of Digital Amplification Tempo Semiconductor 2013 Table of Contents Table of Contents... 2 Table of Figures... 2 1. DDX Technology Overview... 3 2. Comparison

### Interference to Hearing Aids by Digital Mobile Telephones Operating in the 1800 MHz Band.

Interference to Hearing Aids by Digital Mobile Telephones Operating in the 1800 MHz Band. Reference: EB968 Date: January 2008 Author: Eric Burwood (National Acoustic Laboratories) Collaborator: Walter

### Lab 9: Op Amps Lab Assignment

3 class days 1. Differential Amplifier Source: Hands-On chapter 8 (~HH 6.1) Lab 9: Op Amps Lab Assignment Difference amplifier. The parts of the pot on either side of the slider serve as R3 and R4. The

### System? June, is: as much small size especially. efficiency have. Background. Before we. to keep the. know how. adapt the.

How Much Power Do I Need In A Portable Amp System? June, 2012 The typical answer to that question is: as much as you can get! But, in these days of ultra high power, small size amplifiers, it s not that

### General Thoughts on Generator Set - Acoustic Solutions & Noise Control

t: 023 81 290160 www.excelpowerltd.co.uk f: 023 81 290260 info@excelpowerltd.co.uk General Thoughts on Generator Set - Acoustic Solutions & Noise Control Written By Steve Delaney A.M.I.O.A. of TAS Ltd

### What Audio Engineers Should Know About Human Sound Perception. Part 2. Binaural Effects and Spatial Hearing

What Audio Engineers Should Know About Human Sound Perception Part 2. Binaural Effects and Spatial Hearing AES 112 th Convention, Munich AES 113 th Convention, Los Angeles Durand R. Begault Human Factors

### Lab 5: Conservation of Energy

Lab 5: Conservation of Energy Equipment SWS, 1-meter stick, 2-meter stick, heavy duty bench clamp, 90-cm rod, 40-cm rod, 2 double clamps, brass spring, 100-g mass, 500-g mass with 5-cm cardboard square

### ANALYZER BASICS WHAT IS AN FFT SPECTRUM ANALYZER? 2-1

WHAT IS AN FFT SPECTRUM ANALYZER? ANALYZER BASICS The SR760 FFT Spectrum Analyzer takes a time varying input signal, like you would see on an oscilloscope trace, and computes its frequency spectrum. Fourier's

### Chapter 2: Electromagnetic Radiation Radiant Energy I

Chapter 2: Electromagnetic Radiation Radiant Energy I Goals of Period 2 Section 2.1: To introduce electromagnetic radiation Section 2.2: To discuss the wave model of radiant energy Section 2.3: To describe

### 10EaZy SW White Paper Choosing the right hardware

10EaZy SW White Paper Choosing the right hardware Selecting proper hardware for the 10EaZy SW This white paper describes important elements to consider before purchasing hardware intended for sound level

### The Design and Implementation of Multimedia Software

Chapter 10 Auditory Content The Design and Implementation of Multimedia Software David Bernstein Jones and Bartlett Publishers www.jbpub.com David Bernstein (jbpub.com) Multimedia Software Jones and Bartlett

### APPLICATION NOTE AP050830

APPLICATION NOTE AP050830 Selection and use of Ultrasonic Ceramic Transducers Pro-Wave Electronics Corp. E-mail: sales@pro-wave.com.tw URL: http://www.prowave.com.tw The purpose of this application note

### ENGINEERING DATA. Fan Sound & Sound Ratings

Information and Recommendations for the Engineer ED-300 ENGINEERING DATA Aerovent TC Ventco Fiber-Aire Twin City Fan & Blower TC Axial Clarage Fan Sound & Sound Ratings Introduction Small, repetitive pressure

### Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect

Objectives: PS-7.1 Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect Illustrate ways that the energy of waves is transferred by interaction with

### Sound and stringed instruments

Sound and stringed instruments Lecture 14: Sound and strings Reminders/Updates: HW 6 due Monday, 10pm. Exam 2, a week today! 1 Sound so far: Sound is a pressure or density fluctuation carried (usually)

### In modern electronics, it is important to be able to separate a signal into different

Introduction In modern electronics, it is important to be able to separate a signal into different frequency regions. In analog electronics, four classes of filters exist to process an input signal: low-pass,

### Outer Diameter 23 φ mm Face side Dimension 20.1 φ mm. Baffle Opening. Normal 0.5 Watts Maximum 1.0 Watts Sine Wave.

1. MODEL: 23CR08FH-50ND 2 Dimension & Weight Outer Diameter 23 φ mm Face side Dimension 20.1 φ mm Baffle Opening 20.1 φ mm Height Refer to drawing Weight 4.0Grams 3 Magnet Materials Rare Earth Size φ 9.5

### INTERFERENCE OF SOUND WAVES

1/2016 Sound 1/8 INTERFERENCE OF SOUND WAVES PURPOSE: To measure the wavelength, frequency, and propagation speed of ultrasonic sound waves and to observe interference phenomena with ultrasonic sound waves.

### Agilent AN 1316 Optimizing Spectrum Analyzer Amplitude Accuracy

Agilent AN 1316 Optimizing Spectrum Analyzer Amplitude Accuracy Application Note RF & Microwave Spectrum Analyzers Table of Contents 3 3 4 4 5 7 8 8 13 13 14 16 16 Introduction Absolute versus relative

### Capacitors and a Galvanometer

Capacitors and a Galvanometer Object To investigate, understand and verify how capacitances are added together both in series and parallel and to consider the leakage of a capacitor. Also to employ a galvanometer

### Describing Sound Waves. Period. Frequency. Parameters used to completely characterize a sound wave. Chapter 3. Period Frequency Amplitude Power

Parameters used to completely characterize a sound wave Describing Sound Waves Chapter 3 Period Frequency Amplitude Power Intensity Speed Wave Length Period Defined as the time it take one wave vibrate

### AP PHYSICS 2012 SCORING GUIDELINES

AP PHYSICS 2012 SCORING GUIDELINES General Notes About 2012 AP Physics Scoring Guidelines 1. The solutions contain the most common method of solving the free-response questions and the allocation of points

### Convention Paper Presented at the 118th Convention 2005 May 28 31 Barcelona, Spain

Audio Engineering Society Convention Paper Presented at the 118th Convention 25 May 28 31 Barcelona, Spain 6431 This convention paper has been reproduced from the author s advance manuscript, without editing,

### Timing Errors and Jitter

Timing Errors and Jitter Background Mike Story In a sampled (digital) system, samples have to be accurate in level and time. The digital system uses the two bits of information the signal was this big

### Physiology of Hearing Dr. Hesham Kozou Is hearing important? Communica i ti ttion Language Localization sound sources

Physiology of Hearing Dr. Hesham Kozou Undergraduate Round Courses 2008-2009 2009 Is hearing important? Communication Hearing is essential to Language Localization Determining the location of unseen sound

### Aircraft cabin noise synthesis for noise subjective analysis

Aircraft cabin noise synthesis for noise subjective analysis Bruno Arantes Caldeira da Silva Instituto Tecnológico de Aeronáutica São José dos Campos - SP brunoacs@gmail.com Cristiane Aparecida Martins

### College Physics II Lab 8: RC Circuits

INTODUTION ollege Physics II Lab 8: ircuits Peter olnick with Taner Edis Spring 2015 Introduction onsider the circuit shown. (onsult section 23.7 in your textbook.) If left for long enough, the charge

### v = λ f this is the Golden Rule for waves transverse & longitudinal waves Harmonic waves The golden rule for waves Example: wave on a string Review

L 23 Vibrations and Waves [3] resonance clocks pendulum springs harmonic motion mechanical waves sound waves golden rule for waves musical instruments The Doppler effect Doppler radar radar guns Review

### Airborne Sound Insulation

Airborne Sound Insulation with XL2-TA Sound Level Meter This application note describes the verification of the airborne sound insulation in buildings with the XL2-TA Sound Level Meter. All measurements

### Electromagnetic Induction: Faraday's Law

1 Electromagnetic Induction: Faraday's Law OBJECTIVE: To understand how changing magnetic fields can produce electric currents. To examine Lenz's Law and the derivative form of Faraday's Law. EQUIPMENT:

### ARTICLE. Sound in surveillance Adding audio to your IP video solution

ARTICLE Sound in surveillance Adding audio to your IP video solution Table of contents 1. First things first 4 2. Sound advice 4 3. Get closer 5 4. Back and forth 6 5. Get to it 7 Introduction Using audio

### STEREO BLUETOOTH WIRELESS HEADPHONES

STEREO BLUETOOTH WIRELESS HEADPHONES model: AF32 USER MANUAL part of the series PACKAGE CONTENTS Runaway AF32 Stereo Bluetooth Wireless Headphones Charging cable (USB 3.5mm) Stereo audio cable (3.5mm 3.5mm)

### 1000+ AUDIOMETER OPERATING INSTRUCTIONS

1000+ AUDIOMETER OPERATING INSTRUCTIONS AMBCO Model 1000+ is a microprocessor controlled pure tone air conduction audiometer with automated screening test feature. INDEX A. Getting Started Patient Instructions

### Analog to Digital (A-D) and Digital to Analog (D-A) Conversion

UNIVERSITY of PENNSYLVANIA DEPARTMENT of ELECTRICAL and SYSTEMS ENGINEERING Electrical Circuits and Systems II Laboratory ESE206 Analog to Digital (A-D) and Digital to Analog (D-A) Conversion Goals To