various techniques used in forensic phonectics.

1. GURUGHASIDASVISHWAVIDYALAYA, BILASPUR (C.G.)
( A University established by Central University Act 2009 no. 25 of 2009)
DEPARTMENT OF FORENSIC SCIENCE
TOPIC : TECHNIQUES USED IN FORENSIC PHONETICS
- Guided by - Presented by Dr. CHANCHAL
KUMAR PAHELI SHARMA

2. INTRODUCTION
Forensic Phonetics is a field of forensic science that deals with
“acquisition, analysis, interpretation, and evaluation of sound
recordings.”
It helps in Sound Recognition, Voice Analysis, Voice
Identification, Voice Verification & Speaker Profiling.
Voice is an Unique Characteristics of an individual.

3. TYPES OF CASES

4. METHODS INVOLVED IN
VOICE ANALYSIS

5. • It consists of detailed auditory analysis of Voice, Speech & language.
1. Aural-perceptual Approach

6. • It involves the description of parameters of auditory analysis.
• Like Amplitude, frequencies, bandwidth & harmonic intensities of
formants are studied.
3. Audio Latency Process
• According to, Goyal, A. etal.(2019) identification of source of audio
recording with respect to mobile handsets can be determined by
Audio latency feature.
• What is Audio latency ?
2. Phonetic – Acoustic Approach

8. • Li, X. and Mills, M.(2019) reviewed a technique that converted a
speaker’s word into Natural characters/text in the form of phonetic
alphabets.
• Recently Siri, Alexa
& Ok google developed.
4. Voice-operated Phonographic alphabet Writing
Machine

9. • By Dr. Lawrence Kersta
• An instrument that obtains a sound spectrum by analyzing complex
sounds into it’s component’s element.
• Instrumentation includes:- Magnetic tape, Tape scanning device
with a drum, Electronic variable filter, Electronic stylus.
• The Pattern of spectrum formed are called as voice prints
(Unique to every individual).
• Bar voiceprints and contour voiceprints are formed which
helps to determine what was spoken.
• It helps to identify utterances, background sound & voice
mimics.
5. Sound Spectrograph

10. SOUND SPECTROGRAPH. VOICE PRINT SPECTRUM

11. • In a research study by Smith, D.(2016) told that how speaker-sex
discrimination performance improves as a function of stimulus duration
for voiced and whispered vowels.
• It was observed that sex discrimination for voiced and whispered vowels
would be similar for very short durations but, as stimulus duration
increased, voiced vowel performance would improve relative to
whispered vowel performance.
• The Whispered vowels need 3 times longer duration for identification to
listener.
6. Voiced & Whispered vowels – Sex Discrimination

12. 7. Voice Biometrics
• A technology used to verify a
person’s identity using their
unique vocal attributes.
• Improves security, instant
identification and
authentication, reduce
threats.
• Works by creating a voice print or
“template” of a person’s speech
which is encrypted & stored.

13. 8. Voice Stress Analysis
• is a technology that aims to infer the deception from the stress
measured in voice.

14. LEGAL ASPECTS
• Section- 65(B) of Indian Evidence Act, 1972
• It deals with the Admissibility of Electronic Records.

15. REFERENCES
1. Goyal, A. Etal.(2019). Identification of source mobile handset using audio
latency feature, Forensic Science International, 298(2019), 332-335.
2. Maher,R.(2015). Leading an ear in the courtroom: Forensic Acoustics,
Acoustical society of america,11(3),22-29.
3. Li,X. And Mills, M.(2019). Vocal features: from voice identification to speech
recognition by machine, Technology and culture, 60(2),129-160.
4. Smith,D.(2016), Speaker sex discrimination for voiced and whispered vowels at
short duration, Sage journals, 1-13.
5. https://www.sfu.ca/sonic-studio/handbook/Spectrograph.html
6. https://what-when-how.com/forensic-sciences/voice-analysis/
7. https://www.owenforensicservices.com/voice-identification-the-aural-
spectrographic-method/
8. https://youtu.be/urIbPW6ulww

16. THANKYOU