Technical Foundations of Forensic Speech Science - LAN00082M

Department: Language and Linguistic Science
Credit value: 20 credits
Credit level: M
Academic year of delivery: 2022-23
- See module specification for other years: 2023-24 2024-25 2025-26

Module summary

This module provides an introduction to a range of areas such as acoustics, human hearing, sound recording, signal processing and analysis that underpin the technical areas of forensic speech science. We will discover how this fundamental knowledge is applied in casework, including enhancement, authentication and automatic speaker recognition. We will develop practical auditory and technical analysis skills and examine a variety of real casework materials.

Module will run

Occurrence	Teaching period
A	Spring Term 2022-23

Module aims

To give students an understanding of the fundamentals of areas such as acoustics, human hearing, sound recording, signal processing and analysis that underpin the technical areas of forensic speech science including enhancement, authentication and automatic speaker recognition
To give students an understanding of how this fundamental knowledge is applied in the analysis methods used in these types of forensic casework
To give students the skills to critically assess audio recordings and identify their salient acoustic and technical characteristics
To give students the skills to select and correctly apply the appropriate processing and analysis tools when examining speech and audio recordings
To build on the technical and forensic casework content introduced in the Term 1 module ‘Introduction to Forensic Speech Science’
To give students exposure to a range of real casework materials and give them the opportunity to examine it using the knowledge and skills developed in the module

Module learning outcomes

The students will know and understand the fundamentals of acoustics including:

Sound sources
How sound propagates and interacts
How sound is characterised and measured
The students will know and understand the fundamentals of human hearing including:
The basics of human hearing
Non-linear frequency and amplitude response
Frequency and temporal masking
Speech perception and intelligibility

The students will know and understand the fundamentals of sound recording including:

The elements of the recording chain
Recording and encoding formats

The students will know and understand the fundamentals of signal processing and analysis including:

Digitisation
Time domain and frequency domain representations of signals
Characterisation of signals
Simple analysis techniques involving waveforms, spectrograms and spectra
Filtering processes
Convolution and correlation
Advanced analysis techniques – LPC, MFCC

The students will know and understand the fundamentals of audio enhancement including:

Types and sources of noise and other speech intelligibility problems encountered in casework
The principles of a range of filters and processes used in audio enhancement
The appropriate uses of the filters and their limitations
Methods of assessing improvement

The students will know and understand the fundamentals of authentication including:

Editing methods
Detection of editing via auditory and acoustic analysis methods
ENF analysis

The students will understand the fundamentals of automatic speaker recognition:

Speaker modelling
Comparison of speaker models
System evaluation and performance

The students will be able to do the following:

Describe the characteristics of audio recordings based on auditory examinations
Use software to analyse audio recordings and determine their characteristics
Use software to enhance audio recordings
Apply a range of analysis methods used in the authentication of audio recordings

Indicative assessment

Task	% of module mark
Essay/coursework	30
Online Exam - 24 hrs (Centrally scheduled)	70

Special assessment rules

None

Indicative reassessment

Task	% of module mark
Essay/coursework	30
Online Exam - 24 hrs (Centrally scheduled)	70

Module feedback

Written feedback on the formative lab report will be provided within 2 weeks of submission. Written feedback on the summative lab report will be provided within 3 weeks of submission. General feedback may also be given to the group as a whole and the course convener will be available to discuss individual feedback if necessary.

Feedback will be given after the open exam marks have been released and students will be able to see their own exam papers.