IEEE 269-2019 pdf download

IEEE 269-2019 pdf download.IEEE Standard for Measuring Electroacoustic Performance of Communication Devices.
loudspeaker: An electroacoustic transducer that converts an electrical signal to sound and delivers it to the ear from a distance of several centimeters or greater.
method: A formal, well-documented approach for accomplishing a task.
metric: A quantitative measure of the degree to which a system, component, or process possesses a given attribute, such as signal-to-noise ratio.
microphone: An electroacoustic transducer that converts sound to an electrical signal.
mouth reference point (MRP): A point on the axis of the mouth simulator, 25 mm in front of the center of the external lip plane.
mouth simulator: A device consisting of a loudspeaker mounted in an enclosure and having a directivity and radiation pattern similar to those of the average human mouth.
narrowband (NB): Bandwidth consistent with 8 kHz sampling rate, typically 100 Hz to 3400 Hz or 300 Hz to 3400 Hz. Usually refers to a device or transmission channel.
natural field (NF): Sound field consisting of both free field and diffuse field components, such as found in a typical room.
noise discriminator/noise guard/noise monitor: A circuit or algorithm intended to discriminate between speech and noise. It can affect switching, transmission, and/or noise performance.
pinna: The flexible part of the outer ear at the side of the head.
receive: Speech transmission path from the network to the ear of the terminal user.
receive electrical test point (RETP): The point in reference codec, wireless reference base station, or a battery feed circuit at which signals are applied to the terminal in the receive direction. For further discussions on wireless interfaces, see appropriate wireless standards.
receiver: An electroacoustic transducer that converts an electrical signal to sound and delivers it directly to the ear, sealed or unsealed.
reference codec: A codec that approaches the performance of an ideal codec and has superior, well- defined characteristics used for testing digital terminals.
reference receive volume control setting: The setting of one or more receive volume controls of a terminal or subsystem that results in 6 dB of conversational gain, at nominal input level.
reference send level control setting: The setting of one or more send level controls of a terminal or subsystem that results in a nominal output level, at nominal input level.
send: Speech transmission path from the mouth of the terminal user to the network.
send electrical test point (SETP): The point in a reference codec, wireless reference base station, or battery feed circuit at which signals coming from the terminal in the send direction are accessed. For further discussions on wireless interfaces, see appropriate wireless standards.
sidetone: Speech transmission path from the microphone to the receiver of the handset or headset. See also: listener sidetone and talker sidetone.
single frequency interference (SF1): An audible impairment that can be perceived as a tone relative to the overall noise level.
single-talk (ST): One talker speaking while the opposite transmission direction is silent.
sound pressure level: The level, in decibels, of a sound is 20 times the logarithm to the base 10 of the ratio of the pressure of the sound to the reference pressure.
NOTE I—For this standard, the reference pressure is normally 1 pascal (Pa), and sound pressure levels are expressed in decibels re 1 Pa (dBPa). When a reference pressure of 20 iPa is used, the sound pressure level rill be expressed as dBSPL. Unless otherwise indicated, root-mean-square values of pressure are used. Most telephony acoustic measurements are referenced to 1 Pa (1 newton per square meter). However, measurements such as receive noise and room noise are generally referenced to 20 iPa.
NOTE 2—0 dB Pa 94 dBSPL, 0 dBSPL — 20 j.tPa, 1 Pa 1 N/m2. A-weighted sound pressure level in decibels (dBSPL, A-weighted) is often abbreviated as dI3A. (Sec ANSI S 1.4-1983.)
speakerphone: A device for connection directly or indirectly to an analog or digital telephone network capable of two-way voice communication without close coupling to the user’s mouth or ear. A loudspeaker is used as a terminal receiver. The microphone(s) may be embedded or external.
spectrum: A distribution of amplitude (or phase, or some other quantity) as a function of frequency. It is often expressed in bands. Bands may be of constant percentage width, such as 1/3 or 1/12 octave bands (—23% and —6% of the center frequency, respectively). Bands may also be of fixed width, regardless of center frequency (e.g., 50 Hz). Instead of bands, a spectrum may also be expressed as spectrum density, which is equivalent to 1 Hz bands.
superwideband (SWB): Bandwidth consistent with 32 kHz sampling rate, typically 50 Hz to 14 000 Hz. Usually refers to a device or transmission channel.
switching time (Ts): Time taken to switch from one transmission direction to the other in alternating single talk conversation.