To attain a clear signal to quantization noise ratio, the number of samples should be increased. By increasing the sampling depth, the quantization error can be minimized. By companding process, the quantization noise and distortion levels can be minimized. Companding improves response for low amplitude signals.
Kedem  defined ZCR as the measure of dominant frequency in the signal. ZCR is the common feature that is used for music/speech discrimination due to its simplicity. It is also used in other audio domains such as highlight detection , speech analysis , singer  and environmental sound detection . Linear prediction zero crossing ration (LP-ZCR) is defined as the ration between the zero crossing count of the waveform and the zero crossing count of the linear prediction analysis filter . These features help to discriminate between speech and non-speech audio signal.
Sound is (a) the physical transmission of a disorder (energy) in a standard and the physiological response generally to pressure waves in air. However, the sound spectrum has much lower frequencies and is much simpler, with only three frequency regions; the infrasonic region (f<20Hz), the audible region (20Hz20 KHz), (Shipman-Wilson-Higgins, 2013). Depending on the volume of sound can be determined as a low or high frequencies. Sound is a type of longitudinal wave that originates as the vibration of a medium (such as a person’s vocal cords or a guitar string) and travels through gases, liquids, and elastic solids as variations of pressure and density. The loudness of a sound perceived by the ear depends on the amplitude of the sound wave and is measured in decibel, while its pitch depends on it frequency measured in hertz, (Shipman-Wilson-Higgins, 2013).
A special characteristic of the cochlea and the auditory nerve. It means that the apical region of the cochlea (and the nerve near this region) is more sensitive to low frequencies and that the basal region is more sensitive to high-frequencies. The relationship between the most basal to the most apical region is a progression from high-to-low frequency sensitivity. Filters. Filters are used to divide, electronically, acoustic signals into different ranges.
12-tone equal temperament. Harmonicity is a characteristic that differentiates harmonic sounds from in-harmonic sounds. D. Cepstral Features Cepstral frequency are log magnitude representations in which the frequency are smoothed and they possess timbral properties and pitch. They have orthogonal basis which helps in performing similarity comparisons. These are widely used all of audio extraction.
Other components more specific to FM receivers are mixers combined with local oscillators used for frequency manipulation, limiters to control amplitude, de-emphasis and other filter circuits. 2 Mathematics of FM Unlike amplitude modulation (AM) where the message or modulating signal, call it m(t), is used to modulate the amplitude of the carrier signal, frequency modulation, as the name implies, uses m(t) to transform the frequency of the carrier. The amplitude of an FM signal should remain constant during the modulating process; an important property of FM. A general FM signal can be described by the following:1 ¦µFM(t) = Acos(¦È... ... middle of paper ... ...n its output proportional to s(t). Over a short time interval, this variation ¡Ö C(wc-wo)t. Thus, the system continues to loop until the frequency of the VCO output matches or ¡°locks¡± onto the incoming frequency.
High PAPR occurs when the signal in the subchannels add constructively in phase. Because of modulation, high peaks are produced. Once multiple sinusoids, which are in phase, added together to form multi carrier signal high peaks are generated. On the other hand, the ... ... middle of paper ... ... region. However, this solution decreases the PA power efficiency.
The complex sound, on the other hand, consists of a fundamental frequency (which is the lowest one and usually carries most of the intensity) and of some other called overtones. When these overtones are integer multiples of the fundamental (including the fundamental), then we talk about harmonic overtones. Let’s now examine the qualities of sound. The characteristics of sound can be classified into two categories: Objective and Subjective qualities. Objective qualities are related to the physical properties of sound, such as intensity, frequency and frequency spectrum, which can be measured by the use of specific instrumentation.
Introduction: Human ear is capable of hearing sounds with frequencies of about 30Hz – 20 kHz. Sound waves are able to travel best through rigid solids rather than through liquids and gases. However, human ears have got accustomed to sound waves passing through air, so are able to hear various things. The loudness of the sound is based on the incoming waves’ amplitude whereas the pitch of the sound is based on the incoming waves’ frequency. Musical instruments work by building up regular vibrations like in the case of strings, skins, tubes of air which results in the surrounding air vibrating with the same pattern causing melodious music.
Sound is both the mechanical energy of waves and the sensation produced by receptors in the brain (1). Each wave has an amplitude and a frequency. The amplitude of a vibration corresponds to its volume and is measured by decibels on a logarithmic scale. Frequency is logarithmic, as well, but corresponds to differences in pitch. Greater frequency results in a higher pitch.