Return to the Poza Consulting Services Home Page

Audio Recordings: Evidence, Experts and Technology

Gruber, J. S., Poza, F. and Pellicano, A. J.
1993: 48 Am Jur Trials, Lawyers Cooperative Publishing.


ARTICLE OUTLINE


I. PREFATORY COMMENTS (1-11)

A. Introduction (1-5)
B. Scope of Article (6-9)
C. Terminolgy (10, 11)
II. BASICS OF SOUND AND AUDIO RECORDING (12-30)

A. Sound, Speech, and Sound Waves (12-16)
B. Theory of Audio Recording (17-20)
C. Evolution of Audio Recording Devices (21-26)
D. Auxiliary Equipment (27-30)
III. ANALOG AUDIO RECORDERS (31-40)

A. CONCEPT BEHIND ANALOG RECORDING (31-33)
B. Analog Recorders Using Magnetic Tape Storage Medium (34-38)
C. Analog Recorders Using Other Storage Mediums (39, 40)
IV. DIGITAL AUDIO RECORDERS (41-67)

A. Concept Behind Digital Recording (41-44)
B. Digital Recorders Using Magnetic Tape Storage Medium (45-50)
C. Digital Recorders Using Tapeless Magnetic Storage Medium (Computer-Recorders) (51-61)
D. Digital Recorders Using Non-Magnetic Storage Medium (62-67)
V. FUTURE OF AUDIO RECORDING DEVICES AND STORAGE MEDIUMS ( 68-75)

A. Trends with Implications for the Legal Practitioner (68-73)
B. Growth of Related Technologies (74, 75)
VI. USES OF AUDIO RECORDINGS IN THE LEGAL SYSTEM (76-87)

A. Current Evidentiary Usage (76-80)
B. Miscellaneous Uses (81-83)
C. Pros and Cons of Audio Recordings as Evidence (84-87)
VII. OVERVIEW OF EDITING, FALSIFICATION, AND FABRICATION ( 89-109)

A. Terminology and Conceptual Relationships (88-93)
B. Ability to Falsify and Detect Falsification (94-101)
C. Techniques (102-105)
D. Practical and Legal Ramifications (106-109)
VIII. EDITING CONTEMPORANEOUS WITH RECORDING (110-114)
IX. EDITING THAT PHYSICALLY AFFECTS THE SOURCE RECORDING (115-128)

A. Splicing of Tapes (115-118)
B. Over-Recording (119-124)
C. Tape Erasure (125-128)
X. EDITING THAT DOES NOT PHYSICALLY AFFECT SOURCE RECORDING (129-146)

A. Re-Recording (Dubbing) (129-132)
B. Potentially Undetectable Digital Re-Recording (133-135)
C. Synchronization (136-138)
D. Enhancement of Recordings (139-146)
XI. FABRICATION OF AUDIO RECORDINGS (147-163)

A. Types of Speech Fabrication (147-157)
B. Detectability of and Advances in Speech Fabrication Methods ( 158-163)
XII. CONSULTING THE FORENSIC AUDIO EXPERT (164-183)

A. Emerging Discipline of Forensic Audio (164-167)
B. Determining Whether to Consult Forensic Audio Expert(s) ( 168-172)
C. Choosing the Forensic Audio Expert (173-178)
D. Expert's Ethics (179-183)
XIII. PRACTICAL AND EVIDENTIARY CONSIDERATIONS WHEN USING A FORENSIC AUDIO EXPERT (184-202)

A. Qualifying the Expert (184, 185)
B. Expert's Proper Role: Technical "Authentication" Versus Legal Authentication (186-189)
C. Evidentiary and Scientific Limitations on Expert's Testimony ( 190-196)
D. Foundational Checklists for Expert Forensic Audio Testimony ( 197-199)
E. Other Considerations (200-202)
XIV. TECHNICAL "AUTHENTICAITION" BY FORENSIC AUDIO EXPERT (203-247)

A. Overview (203-210)
B. Variations and Commonalities in Experts' Protocols (211-214)
C. Record Interruption Signatures (215-220)
D. Acoustic Anomalies (221-223)
E. Obtaining and Examining Original Recording and Recorder ( 224-227)
F. Non-Instrumental Activities and Techniques (228-234)
0. Instrumental Techniques (235-247)
XV. ADMISSIBILITY OF AUDIO EVIDENCE (248-267)

A. In General (248-254)
B. Materiality, Relevance and Competency (255-258)
C. Indistinct, Incomplete, or Inaudible Recordings (259-261)
D. Miscellaneous Objections to Admissibility (262-267)
XVI. AUTHENTICATION AND LAYING OF FOUNDATION (268-292)

A. In General (268-277)
B. Specific Foundational Criteria (278-288)
C. Re-Recordings (289-292)
XVII. PRACTICAL TRIAL CONSIDERATIONS (293-299)


Return to the Poza Consulting Services Home Page