Microphone
A microphone (colloquially cried a mic or mike; baith pronoonced /ˈmaɪk/)[1] is an acoustic-tae-electric transducer or sensor that converts soond intae an electrical signal. Microphones are uised in monie things, sic as telephones, tape recorders, karaoke systems, hearin aids, film production, live an recordit audio engineerin, FRS radios, megaphones, in radio an telly broadcastin an in computers for recordin vyce, speech recognition, VoIP, an for non-acoustic purposes sic as ultrasonic checkin or knock sensors.
Maist microphones the day uise electromagnetic induction (dynamic microphone), capacitance chynge (condenser microphone), piezoelectric generation, or licht modulation tae produce an electrical voltage signal frae mechanical vibration.
Polar patterns
[eedit | edit soorce]Microphone polar sensitivity. Microphone is parallel tae the page facin upwarts in ilka diagram.
Omnidirectional 
Subcardioid 
Cardioid 
Supercardioid 
Hypercardioid 
Bi-directional or Figure of 8 
Lobar
Cardioid, hypercardioid, supercardioid, subcardioid
[eedit | edit soorce]Bi combinin the twa components in different ratios, ony pattern atween omni an figure-8 can be got; thegither they mak up the first-order cardioid faimily. Common shapes include:
- A hyper-cardioid microphone is similar tae cardioid, but wi a wee bit bigger figure-8 component, sae it haes a tichter area o front sensitivity an a smaer lobe o rear sensitivity. It is produced bi combinin the twa components in a 3:1 ratio, makin nulls at 109.5°. This ratio maximises the directivity factor (or directivity index).[2][3]
- A super-cardioid microphone is similar tae a hyper-cardioid, but thare is mair front pickup an less rear pickup. It is produced wi aboot a 5:3 ratio, wi nulls at 126.9°. This ratio maximises the front-back ratio; the energy ratio atween front an rear radiation.[2][3]
- The sub-cardioid microphone haes nae null points. It is produced wi aboot a 7:3 ratio, wi 3–10 db level atween the front an back pickup.[4]
Three sic cardioid microphones/hydrophones coud be orthogonally orientit as a collocated triad tae improve the gain an create a steerable beampattern.[5][6]
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References
[eedit | edit soorce]- ↑ Zimmer, Ben (29 Julie 2010). "How Should 'Microphone' be Abbreviated?". The New York Times. Retrieved 10 September 2010.
- 1 2 Sena, E. De; Hacihabiboglu, H.; Cvetkovic, Z. (Januar 2012). "On the Design and Implementation of Higher Order Differential Microphones – IEEE Journals & Magazine". IEEE Transactions on Audio, Speech, and Language Processing (in Inglis). 20 (1): 162–174. doi:10.1109/TASL.2011.2159204. S2CID 206602089.
- 1 2 Benesty, Jacob; Jingdong, Chen (23 October 2012). Study and Design of Differential Microphone Arrays (in Inglis). Springer Science & Business Media. ISBN 9783642337529.
- ↑ Dave Berners (December 2005). "Ask the Doctors: The Physics of Mid-Side (MS) Miking". Universal Audio WebZine. Universal Audio. Archived frae the original on 9 Julie 2013. Retrieved 30 Julie 2013.
- ↑ Wong, Kainam; Nnonyelu, Chibuzo; Wu, Yue (Februar 2018). "A Triad of Cardioid Sensors in Orthogonal Orientation and Spatial Collocation – Its Spatial-Matched-Filter-Type Beam-Pattern". IEEE Transactions on Signal Processing. 66 (4): 895–906. Bibcode:2018ITSP...66..895W. doi:10.1109/TSP.2017.2773419. S2CID 3298960. Retrieved 1 Februar 2021.
- ↑ Nnonyelu, Chibuzo; Wong, Kainam; Wu, Yue (Januar 2019). "Cardioid microphones/hydrophones in a collocated and orthogonal triad—A steerable beamformer with no beam-pointing error". The Journal of the Acoustical Society of America. 145 (1): 575–588. Bibcode:2019ASAJ..145..575N. doi:10.1121/1.5087697. PMID 30710946. S2CID 73422758. Archived frae the original on 6 November 2021. Retrieved 1 Februar 2021.