38 results about "Critical band" patented technology

An improved audio coding technique encodes audio having a low frequency transient signal, using a long block, but with a set of adapted masking thresholds. Upon identifying an audio window that contains a low frequency transient signal, masking thresholds for the long block may be calculated as usual. A set of masking thresholds calculated for the 8 short blocks corresponding to the long block are calculated. The masking thresholds for low frequency critical bands are adapted based on the thresholds calculated for the short blocks, and the resulting adapted masking thresholds are used to encode the long block of audio data. The result is encoded audio with rich harmonic content and negligible coder noise resulting from the low frequency transient signal.

A method, system and computer readable medium for increasing the audio perceptual loudness includes shifting at least one frequency of a first audio signal to create a second audio signal so as to increase the audio perceptual loudness. The power level of the second audio signal is not more than a power level of the first audio signal. The method also includes generating high-audio perceptual loudness tone alert sequences based on psychoacoustic and audiometric data. It further includes acquiring a listener's threshold audio profile; adding the listener's audio profile to the loudness sensitivity curve for producing the listener's tonal sensitivity curve; determining a required dB scaling for critical band tones from the listener's tonal sensitivity curve; normalizing the tonal sensitivity curve for creating a decibel curve; selecting a frequency range of the tones by using the tonal sensitivity curve; and spacing the sequence of tones along a critical band scale.

A method and apparatus for detecting speech segments of a speech signal processing device is provided. A critical band is divided into a certain number of regions according to noise frequency characteristics, a signal threshold and a noise threshold are set for each of the regions, and it is determined whether each frame is a speech segment or noise segment by comparing the log energy calculated for each region to the corresponding signal threshold and noise threshold. Therefore, a speech segment can be detected rapidly and accurately by using a small number of operations even in a noise environment.

A flexible apparatus for, and method of, acoustically improving an environment permits manual adjustment by one or more local or remote users using a simple graphical interface and automatic adjustment of the system parameters once the manual adjustment is performed. The inputs are weighted by distance from the physical apparatus. The apparatus includes a receiver, a converter, an analyser, a processor and a sound generator. The acoustic energy impinges on the receiver and is converted to an electrical signal by the converter. The analyser receives the electrical signal from the receiver, analyzes the electrical signal, and generates data analysis signals in response to the analyzed electrical signal. The processor produces sound signals based on the data analysis signals from the analyser in each critical band. The sound generator provides sound based on the sound signals. This permits the users to define the sound heard in a set space.

A non-iterative and computationally efficient bit allocation technique for perceptual audio coders employing uniform quantization schemes. This is achieved by computing a target MNR for all critical bands in a frame using a target bit rate and associated SMRs. Associated SNRs are then computed for the critical bands using the computed target MNR and the associated SMRs. Bits are then allocated to the critical bands based on the computed associated SNRs.

The invention relates to a vehicle noise sound quality roughness information processing method which comprises the following steps: (1), segmenting noise signals and windowing; (2), carrying out Fourier transformation to the noise signals after windowing, calculating out the exciting sound level of noise signals on a critical band; (3), designing mutually superimposed passages on the critical band, dividing the exciting sound level onto the passages so as to form sub noise signals, then carrying out inverse Fourier transform to the noise signals, so as to obtain time domain sub signals at the exciting sound level; (4), carrying out inverse Fourier transform after demodulation to the time domain sub signals at the exciting sound level, so as to obtain a signal time domain value after modulation, and then calculating out the modulation indexes of each passage; (5), calculating out the related coefficient and the carrier frequency weighting factor among the noise signals of all the passages; (6), calculating out the roughness of the noise signals on each passage and calculating out the total roughness. Compared with the prior art, the vehicle noise sound quality roughness information processing method provided by the invention takes auditory perception characteristics of human ears into consideration, and has the advantages of easiness in method understanding, high precision and the like.