Listed below is a glossary of technology terms used within this website. The Glossary includes general technology terms and also terms featured in various Audience diagrams.



General Terms:  A – E | F – J | K – O | P – T | U -- Z

Acoustic Echo Cancellation - The elimination of an echo in a two-way voice transmission, used to enhance voice communications.


Audio Codecs - A codec is a process that compresses/decompresses audio data according to a given format. The objective of a codec algorithm is to represent the high-fidelity audio signal with minimum number of bits while retaining the quality. This can effectively reduce the storage space and the bandwidth required for transmission of the stored audio.

Auditory Scene Analysis (ASA)
– Refers to the processes that allow the human auditory system to perceive and organize sound. The term, first coined by psychologist Albert Bregman, is used to define the principles the human auditory system employs to organize acoustic inputs into perceptually meaningful elements.

– The IC (integrated circuit) is self-calibrating. No engineering intervention required.

Baseband Chipsets
– An IC (integrated circuit) that is mainly used in a mobile phone to process communication functions.

– The stem-like part of the brain that is connected to the spinal cord. It manages messages going between the brain and the rest of the body and is involved in controlling vital functions, movement, sensation, and functions such as breathing, heart rate, blood pressure.

CASA (Computational Auditory Scene Analysis) –
Refers to the field of study that attempts to recreate sound source separation in the same manner as human hearing in machines, to group and process complex mixtures of sound.

– The act of speaking into a mobile phone that is positioned close to the sound source, your mouth.

– Part of the inner ear, it’s the snail-shaped tube that converts mechanical energy (sound vibrations) into nerve impulses sent to the brain.

Cortex –
The outermost layer of the cerebral hemispheres of the brain. It is responsible for all forms of conscious experience, including perception, emotion, thought and planning.

– The alteration of the original shape (or other characteristic) of an object, image, sound, waveform. Distortion is usually unwanted, and often many methods are employed to minimize it in practice.

DSP or Digital Signal Processing –
A category of techniques used to analyze and process signals from sources such as sound. Signals are converted into digital data and analyzed through the use of various algorithms.

Dynamic Noise Suppression
– The ability to effectively suppress all types of noise, whether a sound source is steady and constant, or transitory and moving.

Far-talk –
Refers to the act of speaking into a mobile phone positioned away from the sound source, your mouth, as when using the phone’s speakerphone function.

Fast Cochlea Transform™ (FCT)
– Audience’s proprietary technology that separates sound into its frequency components to map the digital audio stream in a three-dimensional spectral representation of the sound mixture – operating like the cochlea in the human ear, which transforms sound pressure waves into electrical information that the brain can interpret. The FCT decomposes the sound into its frequency components, enables the cues in the audio stream to be analyzed, and the energy to be grouped by source according to the principles of Computational Auditory Scene Analysis.

Fast Fourier Transform (FFT)
– A computer algorithm used in digital signal processing (DSP) to convert time domain signals into frequency domain representations.

Full Duplex
– A channel providing simultaneous transmission in both directions, as in simultaneous, two-way communication.

– Whole number multiples of the fundamental frequency that determines the tone rather than the pitch of sound. 

Host Interface
– Refers to the connection between an IC (integrated circuit) and the baseband or application voice processor.

Integrated Circuit (IC) –
A miniaturized electronic circuit that has been manufactured in the surface of a thin substrate of semiconductor material. In the electronics industry, Integrated Circuit is the formal name for what is commonly known as a “chip”.

Inverse Fast Cochlea Transform
– The process used by Audience technology to convert the Fast Cochlea Transform data back into reconstructed, cleaned-up, high-quality digital audio, which is then converted to an analog signal, and made available for transmission.

Log-Frequency Scale –
A scale with frequency represented in logarithmic values and increments.

MMS (Multimedia Messaging Service)
– An enhancement of SMS (Short Messaging Service) text messaging that allows a user to include images, audio, video and graphics files with a text message transmitted to a mobile phone.

– Mean opinion score (MOS) provides a numerical indication of perceived quality. It is a subjective measurement obtained by having people listen to calls and rate the audio quality from 1 (lowest) to 5 (highest). The MOS score is generated by averaging the results for a particular codec.

Multi-Band Compander (MBC)
– A compander works by compressing or expanding the dynamic range of an analog electronic signal such as sound. A multi-band companding system includes compression and expansion circuits in which each element is utilized in connection with a number of frequency bands.

Non-Stationary Noise
– Noise that is characterized by rapid or random change in characteristics such as pitch, space and onset time. Examples include music, a person talking, keyboard typing, etc. By the time non-stationary noise is recognized as noise, it has already passed, so it requires more sophisticated noise-suppression techniques.

Omni Directional Mic
– Microphones that pick up sounds from virtually any direction, as opposed to unidirectional mics that only pick up sounds aimed directly into their centers.

Onset Time
– One of the attributes used to interpret sound, helping to identify the location or source of a sound in terms of direction. Because sound travels as physical waves through the air, the time it takes for sound waves to reach the ears will vary, providing information on the location of a sound relative to the listener. The time at which sounds arrive is referred to as onset time.

– One of the attributes used to interpret sound. Pitch refers to the frequency of a sound, or the number of vibrations per second, usually measured in hertz. A sound with a high frequency will have a high pitch, and a shorter wavelength. A low pitch indicates deep tones.

Post-Equalization Filter
– Enables handset manufacturers to manage frequency response.

RoHS Requirements
– RoHS stands for Restriction of Hazardous Substances. RoHS regulations were passed by the EU in 2003 and took effect in 2006. RoHS regulates the amount of 6 select hazardous substances (lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, polybrominateddiphenyl ether) in electronic and electrical equipment.

– Learned patterns.

Sequential Grouping Cues
– Auditory grouping cues that occur across time.

Simultaneous Grouping Cues
– Auditory grouping cues that occur across a frequency.

Spatial Location
– The location of a sound based on its distance and direction. This information can be used to group sounds and differentiate them from the voice of interest.

Stationary Noise
– Noise that has a relatively constant nature in terms of pitch, space, and onset time. This type of noise can be identified and effectively subtracted through conventional signal-processing techniques.

System-on-Chip (SOC)
– Refers to integrating all components of a computer or other electronic system into a single integrated circuit (IC). It may contain digital, analog, mixed-signal, and often, radio-frequency functions – all on a single IC substrate.

Thalamus –
A collection of nerve cells in the brain with the primary role to relay sensory information from other parts of the brain to the cerebral cortex.

Time-Frequency Resolution
– Techniques for characterizing and manipulating signals whose statistics vary in time, such as transient signals.

Voice Color Tuning
– Modifying subjective sound quality by frequency domain emphasis and de-emphasis.

Voice Equalization (VEQ) –
The increase or decrease of voice signal strength to enable increased clarity.

Voice Search
– Also called voice-enabled search, allows the user to use a voice command to search the Internet, on a portable device.



ADC – Analog to Digital Converter.

Application Processor
– An IC (integrated circuit) that processes data in contrast with one that performs control functions.

– Automatic Speech Recognition, technology that enables a computer to identify the words that a person speaks into a microphone or telephone.

– An open wireless technology standard for exchanging data over short distances between fixed and mobile devices.

– Bluetooth Pulse Code Modulation, a method of encoding an audio signal in digital format.

– Digital to Analog Converter.

– Electrically Erasable Programmable Read-Only Memory, a type of non-volatile memory used in computers and other electronic devices to store small amounts of data that must be saved when power is removed.

– General Purpose Input/Output.

I2C Slave
– One side of a specialized serial interface used for inter-IC communications. The “slave” device is dependent upon a “master” device to initiate communications.

Instruction ROM
– Permanent memory of a computer from which application programs can be executed.

Instruction RAM
– The very fast, temporary memory of a computer into which application programs currently in use can be loaded and executed.

I/O Power
– Input/Output power supply.

– Joint Test Access Group, a consortium of individuals from North American companies whose objective is to tackle the challenges of testing high density IC (integrated circuit) devices.

Low Drop-Out regulator is a DC linear voltage regulator, which can operate with a very small input–output differential voltage.

Multiplexor, a device that funnels several different streams of data over a common communications line.

– Noise Suppression, the reduction of unwanted sound.

– Pulse Code Modulation, a method of encoding an audio signal in digital format.

– Pulse-Density Modulation is a form of modulation used to represent an analog signal in the digital domain. In a PDM signal, specific amplitude values are not encoded into pulses as they would be in PCM. Instead it is the relative density of the pulses that corresponds to the analog signal's amplitude.

– Phase Locked Loop, a highly stable electronic circuit that can be used in radios to give accurate, drift-free tuning.

– Power Management Unit, a microcontroller that governs power functions of digital platforms.

– Radio Frequency, an alternating current that generates an electromagnetic field when applied to an antenna. The generated electromagnetic field is suitable for wireless broadcasting and communications.

– An abbreviation for receive when in reference to a communication interface.

SPI Interface
– Serial Peripheral Interface is an asynchronous serial data link standard that operates in full duplex mode. Devices communicate in master/slave mode where the master device initiates the data frame.

– An abbreviation for transmit when in reference to a communication interface.

VEQ (Voice Equalization)
– The increase or decrease of voice signal strength to enable increased clarity.