Research
There exists various types of voice operated switches (VOX) available
today ranging in purpose from high caliber military applications to low
efficiency hobbyist applications. The goal of the VOX is to replace existing
push-to-talk (PTT) forms of communications and create efficient, hands free,
voice activated switches that can perform under noisy conditions while not
clipping the beginning of a voice signal. The following outlines the research
we completed in order to understand and implement a successful VOX device.
Current VOX Devices
High performance
Hobbyist/Commercial
Speech Detection
Analog to digital
conversion[2]
Encoding voice
signals[3]
Differentiating
between noise and speech[4]
Voice detection
activity algorithms[5]
Long-term
spectral divergence (LTSD)
Environmental Effects
DO-160
Environmental
Conditions and Test Procedures for Airborne Equipment
Temperature[6]
Turbulence[7]
Humidity
[1] M. Antunano, J. Spanyers,
Hearing and Noise in Aviation , AM-400-98/3 ed. , Oklahoma City, OK 73125: FAA
Civil Aerospace Medical Institute Aeromedical Education Division
[2] R. J. Helferich,
Analog/digital Voice Storage Cellular Telephone, 1991.
[3] Heinz Teutsch, John
Cornelius Lynch, "System and method for method for improving speech
intelligibility of voice calls using common speech codecs", United States.
US20130262128 A1,Oct 3, 2013.
[4] Chui, Yu-Hsiang B.,
Stern, Richard M. "Minimum Variance Modulation Filter for Robust Speech
Recognition." Internet:
http://www.cs.cmu.edu/~ychiu/ychiu_web_files/MVMF.pdf April 19, 2009 [April 24,
2009].
[5] J. Ramirez, J.C. Segura,
C. Benitez, and A. De la Torre, " Efficient voice activity detection
algorithms using long-term speech information," Elsevier: Speech
Communication, vol. 42, no. 3-4, pp. 271-287, April 2004.
[6] Ma, Liuhong, et al.
"Temperature Dependence Of Electronic Behaviors In N-Type Multiple-Channel
Junction less Transistors." Journal Of Applied Physics 114.12 (2013):
124507. Academic Search Complete. Web. 12 Oct. 2014.
[7]
http://www.sierracases.com/how-transit-cases-protect-electronics-from-vibration/
Last Updated 02/16/14