What is the source filter theory of speech production How does this theory relate to speech sound production?

What is the source filter theory of speech production How does this theory relate to speech sound production?

The source-filter theory describes speech production as a two stage process involving the generation of a sound source, with its own spectral shape and spectral fine structure, which is then shaped or filtered by the resonant properties of the vocal tract.

What information does a spectrogram give you?

A spectrogram is a visual way of representing the signal strength, or “loudness”, of a signal over time at various frequencies present in a particular waveform. Not only can one see whether there is more or less energy at, for example, 2 Hz vs 10 Hz, but one can also see how energy levels vary over time.

What is the meaning of harmonics?

A harmonic is a signal or wave whose frequency is an integral (whole-number) multiple of the frequency of some reference signal or wave. ... Signals occurring at frequencies of 2 f , 4 f , 6 f , etc. are called even harmonics; the signals at frequencies of 3 f , 5 f , 7 f , etc. are called odd harmonics.

How many types of harmonics are there?

two types

What can cause harmonics?

What Causes Harmonics? Harmonics are created by electronic equipment with nonlinear loads drawing in current in abrupt short pulses. The short pulses cause distorted current waveforms, which in turn cause harmonic currents to flow back into other parts of the power system.

Why are there no even harmonics?

In theory, even harmonics should not occur in the supply because for an odd signal of period T (i.e. a signal where - f(t) = f(T-t)), there are no even components of the spectrum. In practice, we do see even harmonics appear, of approximately 1% amplitude compared to line frequency. ... times line frequency.

Why 3rd harmonic is dangerous?

Harmonics causes malfunctioning of electrical/electronic parts, overheating of neutral wires, transformer heating, and malfunctioning of power factor correction capacitors, power generation and transmission losses, disruption of protection, control and communication networks as well as customer loads.

Why do closed pipes only have odd harmonics?

For closed tubes, we can have only odd-numbered harmonics. That's because closed tubes by definition have a node at one end and antinode at the other, so there's no way for even-numbered frequencies to be present.

How can we reduce harmonics in power system?

When a problem occurs, the basic options for controlling harmonics are:

  1. Reduce the harmonic currents produced by the load.
  2. Add filters to either siphon the harmonic currents off the system, block the currents from entering the system, or supply the harmonic currents locally.

Does Harmonics affect power factor?

Harmonics generated by non-linear loads introduce distortion reactive power which will lower power factor. The conventional method of installing power factor correction capacitors however, is not an effective way of increasing power factor under these conditions.

What are the means to reduce harmonics?

The harmonic content can be brought to a reasonable limit of 5 % by one of the methods, by inserting filters between the load and inverter. If there is a high frequency harmonics, these can be reduced by a low size filter.

Why 3rd harmonics is important?

One of the major effects of power system harmonics is to increase the current in the system. This is particularly the case for the third harmonic, which causes a sharp increase in the zero sequence current, and therefore increases the current in the neutral conductor.

What is 3rd 5th and 7th harmonics?

Harmonics are voltages or currents that operate at a frequency that is an integer (whole-number) multiple of the fundamental frequency. So given a 50Hz fundamental waveform, this means a 2nd harmonic frequency would be 100Hz (2 x 50Hz), a 3rd harmonic would be 150Hz (3 x 50Hz), a 5th at 250Hz, a 7th at 350Hz and so on.

What causes Triplen harmonics?

The triplen harmonics that are caused by nonlinear loads can cause issues such as excessive neutral currents, transformer failures, excessive heating of motors, electronic device failures, failed capacitor banks, breakers and fuses tripping, and communication issues related to RFI and noise ingression into the ...

What causes 5th and 7th harmonics?

Synchronous machines (winding pitch produces fifth and seventh harmonics) Variable speed drives used in fans, blowers, pumps, and process drives. Solid-state switches that modulate the current-to-control heating, light intensity, etc. Switched-mode power supplies, used in instrumentation, PCs, televisions, etc.

Which harmonics are dangerous?

Where as a negative sequence harmonic ( 2nd, 5th, 8th, …) rotates in the opposite direction (reverse) of the fundamental frequency. Generally, positive sequence harmonics are undesirable because they are responsible for overheating of conductors, power lines and transformers due to the addition of the waveforms.

How are harmonics calculated?

The frequencies of the various harmonics are multiples of the frequency of the first harmonic. Each harmonic frequency (fn) is given by the equation fn = n • f1 where n is the harmonic number and f1 is the frequency of the first harmonic.

What are the effects of harmonics?

Effects of harmonics in the power system

  • Increase in installation and utility costs.
  • Downtime and loss of productivity.
  • Downtime and nuisance trips of drives and other equipment.
  • The use of larger motors.

What are the disadvantages of harmonics?

Disadvantages of Harmonics:

  • The harmonics flowing in the distribution network downgrade the quality of the electrical power supply. ...
  • Increased losses on the distribution system due to increase in the effective rms current.

What is the effect of harmonic distortion?

Harmonic distortion can have detrimental effects on electrical equipment. Unwanted distortion can increase the current in power systems which results in higher temperatures in neutral conductors and distribution transformers.

What is harmonic distortion and what are its effects?

Harmonic currents produced by nonlinear loads are injected back into the supply systems. These currents can interact adversely with a wide range of power system equipment, most notably capacitors, transformers, and motors, causing additional losses, overheating, and overloading.