(between frequencies)
61electron tube — an electronic device that consists, typically, of a sealed glass bulb containing two or more electrodes: used to generate, amplify, and rectify electric oscillations and alternating currents. Also called electronic tube. Cf. gas tube, vacuum tube …
62light — light1 lightful, adj. lightfully, adv. /luyt/, n., adj., lighter, lightest, v., lighted or lit, lighting. n. 1. something that makes things visible or affords illumination: All colors depend on light. 2. Physics …
63Electronic amplifier — A practical amplifier circuit An electronic amplifier is a device for increasing the power of a signal. It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. In… …
64Subwoofer — A subwoofer is a woofer, or a complete loudspeaker dedicated to the reproduction of bass audio frequencies, from perhaps 150 Hz down as far as 20 Hz, or in rare cases lower. Also known as subs , these are used to augment the low frequency… …
65Microphone — For the indie film, see Microphone (film). Microphones redirects here. For the indie band, see The Microphones. A …
66Radio propagation — is a term used to explain how radio waves behave when they are transmitted, or are propagated from one point on the Earth to another. [ H. P. Westman et al, (ed), Reference Data for Radio Engineers, Fifth Edition , 1968, Howard W. Sams and Co.,… …
67Two-way radio — receiver which only receives content. Two way radios are available in mobile, stationary base and hand held portable configurations. Hand held radios are often called walkie talkies or handie talkies. A push to talk or Press To Transmit button is …
68Pure tone audiometry — (PTA) is the key hearing test used to identify hearing threshold levels of an individual, enabling determination of the degree, type and configuration of a hearing loss. Thus, providing the basis for diagnosis and management. PTA is a subjective …
69Critical band — The term critical band, introduced by Harvey Fletcher in the 1940s, referred to the frequency bandwidth of the then loosely defined auditory filter. Psychophysiologically, beating and auditory roughness sensations can be linked to the inability… …
70Frequency — For other uses, see Frequency (disambiguation). Three cyclically flashing lights, from lowest frequency (top) to highest frequency (bottom). f is the frequency in hertz (Hz), meaning the number of cycles per second. T is the period in seconds (s) …
