Voice Recognition in Forensics
- Science Holic
- 13 hours ago
- 3 min read
Author: Sophie Jin
Editors: Fiona Cheng, Eason Gao, Hwi-On Lee
Artist: Caitland So
Have you ever wondered how detectives use voice recordings to identify speakers, collect evidence, and link suspects to crime? The technique they rely on is voice recognition, a powerful tool that can connect voices to people and provide valuable evidence in criminal investigations. By comparing an unknown recording to a known sample, experts can use special tools to determine if the voiceprints match based on factors such as pitch, tone, and pronunciation. Voice recognition has become a vital tool in modern investigations and continues to play a crucial role in forensic science.
Voice recognition works because every person’s voice is unique. But what exactly makes them special? The human voice is produced when air from the lungs passes through the vocal folds, creating sound waves that travel up the throat and mouth. As the wave moves upward, it is modified by the larynx muscles as well as articulators like the tongue, cheeks, gums, teeth, and lips. The differing sizes and forms of everyone’s vocal organs are what make each person’s voice distinct, which also implies that people’s voices can change by modifying their mouth features.
So how does voice recognition technology work? It consists of two main steps: voiceprint extraction and voiceprint comparison. Voiceprint extraction begins by analyzing the sample recording with a sound spectrograph, creating a visual representation of the person’s voice. This model, called a voiceprint, is unique to each individual, much like a fingerprint. In voiceprint comparison, the extracted voiceprint is compared to others to find potential matches and identify the speaker.
Although voice recognition technology is commonly used in legal cases, there has been controversy surrounding its reliability. There have been several cases where people were falsely convicted of crimes due to faults in voice recognition. For instance, a man named Jerome Prieto spent 10 months in prison because his voice was wrongfully identified in a phone call and took responsibility for a car bombing. Another example is Guy Paul Morin, who was falsely accused of murder after the victim’s mother allegedly recognized his voice. These mistakes often occur because of scientific and technical limitations. As a result, poor audio quality and background noise can make it incredibly difficult to make out words and clearly identify speakers. Moreover, a person’s voice can be intentionally disguised and also vary greatly depending on factors like stress, illness, age, and emotion.
Despite these challenges, researchers have been working towards making improvements in voice recognition technology. Assisted by tools like artificial intelligence, voice recognition is designed to become better at identifying speakers with higher levels of accuracy and recognizing differences in voices. In addition, advancements in noise cancellation have helped improve the audio quality of recordings by eliminating background noise, allowing for clearer analyses of voice samples. Combining voice recognition with other tools such as facial recognition can also provide more precise identification.
Voice recognition has become a powerful tool in the world of forensic science and has proved to be a helpful resource for connecting suspects to crimes. Though it has faced controversy due to technical challenges, experts continue to refine voice recognition for heightened accuracy and efficiency. With even more support and improvement, voice recognition may one day stand as a highly trusted tool in forensic science and continue to bring justice in the legal world.
Citations:
Keep Your Voice Sound. (2017, April 18). Keep Your Voice Sound. NIH News in Health.
Voiceprint analyses | EBSCO. (2024). EBSCO Information Services, Inc. | Www.ebsco.com.
Voice Biometrics: The Essential Guide | PHONEXIA. (n.d.). PHONEXIA Speech Technologies.
Voice identification | police technique. (n.d.). Encyclopedia Britannica.
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