Instrumentation for Research in Speech, Language, and Hearing

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Instrumentation for Research in Speech, Language,
and Hearing

• Arlene Neuman
• aneuman_at_gc.cuny.edu
• [phone]

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Scope of Study

• Hardware for generation of signals, measurement
  of signals, manipulation of signals, output of
  signals
• Software for generation of signals, measurement
  of signals, manipulation of signals

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Objectives

• To learn the principles underlying the
  generation, recording, measurement, modification,
  and analysis of acoustic and electrical signals.
• To learn to use instrumentation and software
  employed for generation, recording, measurement,
  modification, and analysis of signals for speech,
  language, and hearing research. 
• To learn principles of calibration.

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Things to be learned

• How to select appropriate instrumentation
  (hardware/software) for a research project
• Considerations for interconnection of equipment
• Validation of appropriate performance (hardware
  and/or software)
• Establishing calibration procedures
• Documentation

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Assigned Readings

• Baken, R.J. and Orlikoff, R.F. (2000)
• Clinical Measurement of Speech and Voice (Second
  Edition). San Diego Singular Publishing Group.
•  Download the following files http//www.comdis.w
  isc.edu/facstaff/mrchial/index.htm
• Poor Mans Tour of Basic Electronics
• Poor Mans Tour of Basic Electronic Measurement
  Devices
• Poor Mans Tour of Electronic Measurement Systems

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Assigned Readings

• Additional readings will be placed in the
  class folder in the Speech and Hearing Main
  Office.

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Instrumentation
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Examples of Input Transducers

• Microphones
• Analog/Digital Converters
• Accelerometers
• Pressure Gauges, Strain Gauges
• Anemometers
• Respirometers
• Laryngograph

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Examples of Systems

• Amplifiers
• Attenuators
• Filters
• Equalizers
• Compressors
• Expanders
• Recorders

• Signal Generators
• Meters
• Waveform Analyzers
• Waveform Editors
• Frequency Analyzers
• Computers

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Examples of Output Transducers

• Earphones
• Loudspeakers
• Meter Indicators
• Digital/Analog Converters

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What is electricity?

• All substances are made up of atoms
• Although the atom may be broken up into
• sub- atomic particles, the atom is the basic
• unit of matter.
• Each atom is comprised of
• The nucleus
• rotating electrons

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What is electricity?

• Electricity is a form of energy. It is created
  when particles become charged.
• If a state of unbalanced charge exists, electrons
  will move. This constitutes an electric current.

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Basic parameters of electrical signals

• Electrical potential (voltage)
• Current
• Resistance

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Important Terms

• Electrical Potential
• The force that causes electrons (negative
  particles in the atom) to separate and move
  through a conducting material.
• To measure electrical potential we use a
  voltmeter
• The unit of electrical potential is the VOLT

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• Conductor A conductor is a material (usually a
  metal such as copper) that allows electrical
  current to pass easily through. The current is
  made up of electrons.
• Insulator
• An insulator prevents the flow of electricity
• through it.
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Important Terms

• Current
• The rate of flow of electrons
• Measured with an ammeter
• The unit of current is Amperes (amp)
• Household current lt 30 amp

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Important Terms

• Resistance
• Resistance is the property of a substance that
  prevents the flow of electrons. Materials with
  high resistance are called insulators.
• Wires carrying electricity are covered with an
  insulator to prevent electric shock.
• Measured with Ohmmeter
• Unit of measure Ohms

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Important Terms

• Resistance
• Continuity of electrical conduction between 2
  points has a very small resistance
• Insulation or open circuit between two points has
  a very high resistance

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Basic parameters of electrical signals
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Simple Circuit

• Power Source -- eg battery A Path -- eg a
  wire A Load -- eg a lamp A Control -- eg
  switch (Optional) An indicator -- eg Meter
  (Optional)
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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BASIC ELECTRONIC CIRCUITS

• Circuit A circuit is a path for electrons to
  flow through. The path is from a power sources
  negative terminal, through the various components
  and on to the positive terminal.
• NOTE Negatively charged electrons in a conductor
  are attracted to the positive side of the power
  source. http//webhome.idirect.com/jadams/electr
  onics/circuit.htm

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Series Circuit

• A series circuit is one with all the loads in a
  row. There is only ONE path for the electricity
  to flow. If this circuit was a string of light
  bulbs, and one blew out, the remaining bulbs
  would turn off.
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Parallel Circuit

• A parallel circuit is one that has two or more
  paths for the electricity to flow. In other
  words, the loads are parallel to each other. If
  the loads in this circuit were light bulbs and
  one blew out there is still current flowing to
  the others as they are still in a direct path
  from the negative to positive terminals of the
  battery.
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Combination Circuit

• A combination circuit is one that has a
  "combination" of series and parallel paths for
  the electricity to flow. Its properties are a
  synthesis of the two. In this example, the
  parallel section of the circuit is like a
  sub-circuit and actually is part of an over-all
  series circuit.
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Voltage

• Voltage is the electrical force, or "pressure",
  that causes current to flow in a circuit. It is
  measured in VOLTS (V or E). Take a look at the
  diagram.  Voltage is analagous to the force that
  is pushing the water (electrons) forward.
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Current

• Current is the movement of electrical charge
• the flow of electrons through the electronic
  circuit. 
• Current is measured in AMPERES (AMPS, A or I).
  Current would be the flow of water moving through
  the tube (wire).
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Resistance

• Resistance is anything that causes an opposition
  to the flow of electricity in a circuit. It is
  used to control the amount of voltage and/or
  amperage in a circuit. Everything in the circuit
  causes a resistance (even wire). It is measured
  in OHMS (W).
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Cable
Chial, 1998
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GR Connectors

• GR (for General Radio Corporation)
  connectors, also called banana plugs because of
  appearance. Most often these are built in pairs
  (thus, dual-banana), but they also are available
  as single-conductor connectors. GR plugs may have
  labels to designate which contact is signal
  ground, but they are not mechanically
  pre-polarized. Most GR connectors are both male
  and female. GR connector contacts are silver in
  color the insulated housing may be black or some
  other color.(Chial, 1998)

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RCA Connectors

• RCA (for Radio Corporation of America)
  connectors are two-conductor devices, also called
  phono (for phonograph) connectors. Because these
  are commonly used with home-entertainment stereo
  gear, RCA cable assemblies often contain two sets
  of conductors. They also are commonly used with
  home video cameras and recorders. RCA connectors
  are pre-polarized and available in various
  colors.
• (Chial, 1998)

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Canon Connectors

• Canon or XLR connectors are three-conductor
  devices used exclusively with microphones. This
  connector uses conductors numbered 1 (signal), 2
  (signal ground), and 3 (shield or instrument
  ground).XLR connectors are common in professional
  recording applications to eliminate spurious
  electromagnetic noise.
• (Chial, 1998)

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Phone connectors

• Phone connectors were developed by the Bell
  System in the days of manual telephone
  switchboards.Today they are used to connect
  microphones to other equipment, and to connect
  earphones to amplifiers, stereo pre-amplifiers,
  and audiometers. Phone connectors may be
  two-conductor (mono) or three conductor
  (stereo).Two sizes are common (for both mono and
  stereo plugs) 1/4-inch diameter and 1/8-inch
  diameter. ( Chial, 1998)

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BNC connectors

• BNC (for Berkeley Nucleonics Corporation)
  connectors are two-conductor devices. The male
  conductor has a rotating outer shell containing
  slots that mechanically latch to pins on the neck
  of the female connector. BNC connectors are
  mechanically pre-polarized and usually silver in
  color. A thin center pin is for signal the outer
  portion of the connector is signal ground. Most
  electronic test instruments are equipped with
  female BNC connectors. (Chial, 1998)

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Multimeter

• A multimeter is an instrument that allows the
  measurement of voltage, current, and resistance
  with one instrument.

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Electrical Circuits

• Ohms Law
• Kirchoffs Laws

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Ohms Law

• The current in an electrical circuit is directly
  proportional to the voltage and inversely
  proportional to the resistance.
• I V/R
• Or
• V I x R

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Ohms Law

• 1) A steady increase in voltage, in a circuit
  with constant resistance, produces a constant
  linear rise in current.
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Ohms Law

• 2) A steady increase in resistance, in a circuit
  with constant voltage, produces a progressively
  weaker current. 
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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• To determine a missing value, cover it with your
  finger. 
• If you are calculating voltage, cover it and
  you have I X R left (V I times R). 
• If you are calculating amperage, cover it, and
  you have V divided by R left (IV/R).    If
  you are calculating resistance, cover it, and you
  have V divide by I left (RV/I). 
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Ohm's Law

• V is the Voltage measured in volts 
• I is the Current measured in amperes  R is the
  resistance measured in Ohms 

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UNDERSTANDING CALCULATING SERIES CIRCUITS

• The same current flows through each part of a
  series circuit.
• The total resistance of a series circuit is equal
  to the sum of individual resistances.
• Voltage applied to a series circuit is equal to
  the sum of the individual voltage drops. 
• The voltage drop across a resistor in a series
  circuit is directly proportional to the size of
  the resistor. 
• If the circuit is broken at any point, no
  current will flow. 
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Series Circuit

• 1. The same current flows through each part of a
  series circuit."   
• In a series circuit, the amperage at any
  point in the circuit is the same.  This will help
  in calculating circuit values using Ohm's Law. 
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Calculation of Resistance

• To calculate the total resistance of the
  circuit, add the individual values of each
  component in series. 
• RT R1 R2 R3 
• 5 5 10 20 Ohms 
• R total is 20 Ohms
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Calculation of Current

• RT R1 R2 R3  RT 20 Ohms 
• I V / RT  I 20V / 20 Ohms  I 1 Amp 
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Measurement of Voltage Drop

• A voltage drop is the amount the voltage
  lowers when crossing a component from the
  negative side to the positive side in a series
  circuit. 
• If you placed a multimeter across a resistor,
  the voltage drop would be the amount of voltage
  you are reading.  This is pictured with the red
  arrow in the diagram.
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Voltage in series circuit

• Voltage applied to a series circuit is equal to
  the sum of the individual voltage drops.
• V total V1 V2 V3
• V total 10 V
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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UNDERSTANDING CALCULATING PARALLEL CIRCUITS

• A parallel circuit has two or more paths for
  current to flow through. 
• Voltage is the same across each component of the
  parallel circuit. 
• The sum of the currents through each path is
  equal to the total current that flows from the
  source. 
• You can find total resistance in a Parallel
  circuit with the following formula 
• 1/Rt 1/R1 1/R2 1/R3 ...
• Rt R (t)otal 
• If one of the parallel paths is broken, current
  will continue to flow in all the other paths.
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm
•  

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Parallel Circuit

• "1. A parallel circuit has two or more paths for
  current to flow through." 
• http//webhome.idirect.com/jadams/electronics/c
  ircuit.htm

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Parallel Circuit

• "2. Voltage is the same across each component of
  the parallel circuit.
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm
•    
•  
• --

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Parallel Circuit

• "3. The sum of the currents through each path is
  equal to the total current that flows from the
  source." 
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm

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Calculating Total Resistance

• "4. You can find TOTAL RESISTANCE in a Parallel
  circuit with the following formula
• 1/Rt 1/R1 1/R2 1/R3 ...
• 1/Rt 1/4 1/4 1/2
• 1/Rt .25 .25 .5 
• 1/Rt 1
• Rt 1/1
• Rt 1?
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm
•  

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Use Ohms Law to determine current

• a) Calculate total resistance
• 1/RT 1/10? 1/20?
• 1/ RT 3/20?
• 3 RT 20?
• RT 6.67 ?
• b) Calculate total current
•   I total (It) 10V / 6.67 ?
• 1.5 A
• c) Calculate current in each branchI1 10V / 10
  Ohm 1 A I2 10V / 20 Ohm .5 A
• http//webhome.idirect.com/jadams/electronics/cir
  cuit.htm