1. AudiometryAudiometry
 Measurement of auditory functionMeasurement of auditory function
 Pure-tone audiometryPure-tone audiometry implies determination of animplies determination of an
individual’s hearing threshold levels for pure tonesindividual’s hearing threshold levels for pure tones
by air conduction, under monaural earphoneby air conduction, under monaural earphone
listening conditions or by bone conductionlistening conditions or by bone conduction

2. AudiogramAudiogram
 A graph showing individual hearing acuity as aA graph showing individual hearing acuity as a
function of frequencyfunction of frequency

3. AudiometerAudiometer
 An electrical instrument, equipped forAn electrical instrument, equipped for airair
-conduction-conduction with two earphones and a headset thatwith two earphones and a headset that
provides pure tones of known frequencies ofprovides pure tones of known frequencies of
adjustable intensity, used to determine hearingadjustable intensity, used to determine hearing
threshold levels, one ear at a timethreshold levels, one ear at a time
 ForFor bone conductionbone conduction, the audiometer is equipped, the audiometer is equipped
with a bone vibratorwith a bone vibrator
 A clinical audiometer includes both facilities plusA clinical audiometer includes both facilities plus
means for generating calibratedmeans for generating calibrated masking noisemasking noise,,
and an input for speech audiometry as welland an input for speech audiometry as well

4. Courtesy MCS Clinical TrailsCourtesy MCS Clinical Trails

5. Arphi Electronics Private LimitedArphi Electronics Private Limited

6. Welch Allyn GSI 61 Clinical Audiometer Welch Allyn GSI 61 Clinical Audiometer

7. Manual and Self-recordingManual and Self-recording
audiometersaudiometers
 Manual audiometers:Manual audiometers: the tone presentations andthe tone presentations and
noting of the subject’s responses are performednoting of the subject’s responses are performed
manuallymanually
 Self-recording audiometers:Self-recording audiometers: the tone presentation andthe tone presentation and
recording of the subject’s responses are implementedrecording of the subject’s responses are implemented
automaticallyautomatically

8. Sonic boomSonic boom
 Extreme pressure variation orExtreme pressure variation or shock waveshock wave causedcaused
by theby the supersonicsupersonic flight of an aircraftflight of an aircraft
 Sonic boom generates enormous amounts of soundSonic boom generates enormous amounts of sound
energy, sounding much like an explosionenergy, sounding much like an explosion

9. Shock WaveShock Wave
 When an object passes through air at the speed ofWhen an object passes through air at the speed of
sound , it creates a series of pressure wavessound , it creates a series of pressure waves
traveling at the speed of soundtraveling at the speed of sound
 As the speed of the object increases, the waves areAs the speed of the object increases, the waves are
forced together, or compressed, eventually mergingforced together, or compressed, eventually merging
into a singleinto a single shock waveshock wave at the speed of soundat the speed of sound
 This critical speed is known asThis critical speed is known as Mach 1Mach 1 and isand is
approximately 1,225 km/hr at sea levelapproximately 1,225 km/hr at sea level

10. Click on the link belowClick on the link below
 The Doppler Effect and Sonic BoomsThe Doppler Effect and Sonic Booms

11. Click on the link belowClick on the link below
 YouTubeYouTube
- Sonic Boom - Extreme close fly-by- Sonic Boom - Extreme close fly-by

12. Click on the link belowClick on the link below
 Sonic Boom - Google SearchSonic Boom - Google Search

14. Pressure DistributionPressure Distribution
 TheThe pressure distributionpressure distribution at the horizon changesat the horizon changes
into different forms, with a characteristicinto different forms, with a characteristic U-waveU-wave
shapeshape
 The boom is generated continually as long as theThe boom is generated continually as long as the
aircraft is supersonicaircraft is supersonic
 The U-wave trails the aircraft's flight path on theThe U-wave trails the aircraft's flight path on the
horizonhorizon