Phonetics lab seminar 4/25/05

About microphones in general and for speech research:

· excellent page: http://arts.ucsc.edu/ems/music/tech_background/TE-20/teces_20.html

· ANSI standards: Specifications for Laboratory Standard Microphones, Amer. Natl. Stand. Inst. S1.12-1967 (R1977), New York, NY

· from http://www.netyak.com/microphone.htm:

Condenser Refers to the properties of the microphone that convert sound to electricity. Condenser microphones are powered, often by a small voltage from the PC.

Dynamic Refers to the properties of the microphone that convert sound to electricity. Dynamic microphones utilize a magnet and are typically not powered.

Electrostatic Refers to the properties of the microphone that convert sound to electricity. Electrostatic microphones are powered, usually by a small battery.

Omnidirectional Refers to the direction from which the microphone will receive sound.  Omnidirectional microphones pick up sound from all directions.

Unidirectional Refers to the direction from which the microphone will receive sound.  Unidirectional microphones pick up sound from one direction.
Noise canceling Refers to the technology used in some microphones to eliminate background noise and feedback.
Echo canceling Refers to the technology used to eliminate feedback, or echo, between the microphone and speakers.

· Svec (2010) “Guidelines for Selecting Microphones for Human Voice Production Research” (JSLHR) (abstract)

· UCL page on making recordings includes info about microphones

· Picture of connectors from previous Shure webpage (now gone):

Common audio connectors,

from left: XLR male, XLR female, 1/4" male, RCA male, Stereo 3.5 mm male

Things to know about microphones:

· Dynamic microphones are sturdier than condenser, but generally are less sensitive.

· Condenser microphones need a power source, e.g. a pre-amp.

· A head-mounted microphone means that speaker head-movements won’t affect the recording. However, some closure voicing and nasalization will be missed.

· A unidirectional microphone (cardioid pattern) picks up less ambient noise than an omnidirectional microphone (as long as it is pointed at the speaker – that is, the TOP of the microphone should be pointed at the speaker’s mouth).

· A balanced XLR connection introduces less noise than other connections.

· A shorter connecting cable introduces less noise than a long one.

· A microphone with some kind of windscreen will be safer from bilabial plosive releases and other popping sounds that will overload the recording. Positioning the microphone off to the side of the mouth will also help with this.

About our microphones:

The lab has a tabletop microphone: Conneaut Audio Devices (CAD) Equitek IIB (see Henry for this)

electret condenser, variable polar pattern (controlled by switch) including cardioid (unidirectional); 10-18,000 Hz, 132 dB dynamic range; XLR connection

no link for this older model; see www.cadaudio.com/recording.php for newer ones

the head-mounted microphones: Shure SM10A

cardioid, dynamic, close-talk, lowZ; 50-15,000 Hz; XLR

microphones in the cabinet:

Shure SP19L cardioid, dynamic, lowZ, 80-13000 Hz; 1/4” phone

Sony ECM44B miniature wired lavalier (clip-on), omnidirectional, condenser, XLR

CAD U37 USB Studio Recording Microphones, Cardiod, condenser, USB

Sennheiser MKH-415 directional condenser lowZ microphone (long and thin), XLR

with Sennheiser MZA 15-UP battery adapter with XLR connection

(discontinued model not listed online; newer models at http://www.sennheiserusa.com/newsite/category.asp?transid=cat36)

microphone in the aero box: Panasonic microphone cartridges

http://www.digikey.com/scripts/DkSearch/dksus.dll?KeywordSearch (“microphone cartridge”)

[Bruel & Kjaer (B&K) microphones generally used for voice source analysis, but we don’t have any – but the Bureau of Glottal Affairs does.]