IEEE Std 269-2019 pdf download

IEEE Std 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, andlor 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, welldefined 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.
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.
talker sidetone: The direction of speech transmission from mouth to ear of the terminal user.
telephone: A device that, when connected to a telephone network, allows two-way voice communication.
terminal coupling loss (TCL): The loss in the echo path from the receive electrical test point to the send electrical test point. It can be weighted in time, frequency, or both. Terminal coupling loss is also known as “echo return loss” (ERL).
test head: A fixture containing a mouth simulator and an ear simulator located in a specified relationship with each other. See: loudness rating guard-ring position.
threshold level (LTH): The minimum signal level necessary for removing insertion loss.
two—wire transmission: A transmission method, circuit, or system that provides common paths (one pair) for signals in the send and receive directions.