fill the blanks -11
Variations in air pressure are received by the ear and transmitted to the brain in the form of information about the………….,………, and qualits of the sound.
pitch; loudness
The main function of the eardrum is to enhance the effective………….. area for picking up the sound energy
reaceiving area
A large portion of the energy received by the eardrum is transmitted to the oval window by three small bones known as the…………
ossicles
In case of loud sounds, the stirrup may break contact with …… thus strongly …………the sound signal transmission to the inner ear.
oval window; interrups
Pressure waves in the cochlea are converted into electrical impulses in the …………
nerve cell of cochella
At low pitches, a frequency change of less than ……….. can be detected.
3
.If it takes a 3Hz change to be heard at 1000Hz, it takes only about ……… to be heard at 100Hz.
0,3
Zero decibels relative intensity is the threshold of hearing at 10^3Hz, which is accepted to be ………….(…………./cm^2) for standardization.
10^-12 ; 10^-16
Two sounds A and B with intensities IA and IB can be compared by the following relationship: …………………..).
nA-nB (dB) = 10 log10 [Ia/Ib]
Let us consider two sounds A and B with intensities IA and IB respectively. If IA=1000 IB, the intensity difference is then …………dB
30
Loudness is not the same as intensity because it is a subjectivecharacteristic. It depends upon the ……………of the ear at the particular ………………contained in the sound.
sensivity; frequencies
The relative unit of loudness used to label the equal loudness curves is the………………
the phon
The two basic approaches to test hearing loss are ……………and ………… audiometry
pure tone ; speech
The hearing sensitivity curves is flatter at high intensities. Hence the ear´s sensitivity is not so ……………….dependent at high sound intensities.
frequency
Two sounds of the same intensity but different frequencies will not in general be perceived to have the same………
loudness
Testing for hearing loss is referred to as………
audiometry
……………..consist of an electronic oscillator to produce a periodic, electronic signal at the specified frequencies, an attenuator to regulate the loudness, and compatible earphones.
audiometer
The ……………curves are produced in controlled tests. For that purpose subjects are asked to compare the loudness of test tones with a standard tone at 10^3Hz.
equal loudness
There are three internationally accepted standard contour filters, known as the … , ........ and …… contours
A;B;C
The tympatic membrane and the ossicles of the middle ear serve to …………….sound waves. At the same time they offer some protection against very strong sounds.
amplifier
Pitch is considered identical to……
frequency
The term …………..is used to characterize the human auditory response. It is proportional to intensity at a given frequency, but depens on the ear´s sensitivity to…………
loudness ; sound
Sounds with the same basic pitch and loudness can be distinguished by the ear because of differences in…………...
total quality
……….are graphs used to diagnose and monitor hearing loss.
audiogram
A ………… tone is described by a sine wave.
pure
The differences in waveforms are due to the presence of higher frequencies (…………….) superimposed upon the basic frequency.
overtone
At a fixed frequency, an increase in …………..will increase the perceived loudness.
intensity
The range of hearing can be extended by increasing the intensity. However, practical limits can be reached when the intensity is raised to the ………………
physical pain threshold
Every point on a 40 phon equal loudness curve represents a sound that is as loud as a …………. decibel tone at 10^3Hz
40
The three objective characteristics of sound waves are…………, …………… and ……………
intensity; frequency; harmonic content