Forensic Acoustics

Forensic Acoustics is a branch of forensic science that involves the acquisition, analysis, interpretation, and evaluation of audio recordings. This discipline deals with verifying the integrity of audio recordings, enhancing recordings, and identifying speakers. Forensic acoustics encompasses the examination of audio recordings that can be used as evidence in a wide range of contexts, from criminal cases to civil disputes.

Historical Development

Forensic acoustics began to be applied in the 1960s, particularly by the Federal Bureau of Investigation (FBI) in the United States. Initially limited to the analysis of analog recordings, the field has expanded to include the analysis of digital audio recordings with the development of digital technologies. Since digital recordings are susceptible to manipulation, verifying their integrity and authenticity has become increasingly important.

Methods Used in Forensic Acoustics

Various methods are used in forensic acoustic examinations:

• Authentication of Audio Recordings: This is the process of confirming the originality and integrity of recordings. It includes determining whether the recording has been cut, edited, or tampered with.
• Audio Enhancement: Techniques such as noise reduction and filtering are used to make distorted or difficult-to-understand recordings clearer.
• Speaker Identification: This involves analyzing vocal characteristics to determine the identity of the speaker in a particular audio recording.
• Acoustic Event Analysis: Environmental sounds such as gunshots, explosions, or other acoustic events are analyzed to reconstruct incidents and present evidence.

Forensic Acoustics in Turkey

In Turkey, various academic studies have been conducted in the field of forensic acoustics. For example, in his 2018 master's thesis, Sercan Sarman applied machine learning methods to classify gunshot sounds and violent scenes based on audio. In this study, classification success rates of up to 66% for gunshots and 62% for violent scenes were achieved.

Additionally, in a 2016 study by Ahmet Emir Dirik and Saffet Vatansever, the detectability of recording times using acoustic power grid noise in audio recordings was examined. This study aimed to verify the time stamps of recordings by analyzing the components of the electric network frequency (ENF) reflected in audio recordings.

In another thesis by Yunus Korkmaz in 2018, forensic accent analysis was carried out based on the formant frequency values of vowels in Turkish. This study revealed regional differences in formant frequencies and achieved classification success rates of up to 90%.

Challenges Faced

One of the main challenges in forensic acoustics is verifying the authenticity and integrity of digital recordings, especially since they are prone to manipulation. In the future, the use of more advanced analysis techniques and AI-based methods aims to increase the accuracy and reliability of forensic acoustic examinations.

Forensic acoustics is becoming an increasingly important branch of forensic science, in parallel with technological developments. The widespread use of digital audio recordings has increased the need to assess their admissibility and reliability as evidence. Analyses based on the physical and digital properties of sound contribute to the acquisition of effective evidence in both criminal trials and civil disputes.

However, due to the technical expertise required and the potential for differing interpretations, a careful approach is essential in determining the evidential value. Although the number of academic studies on this subject is increasing in Turkey, it is observed that the standards for practical application are not yet fully institutionalized. In the future, systematic and reliable integration of forensic acoustics into both academic and judicial systems will enable more effective and accurate use of this discipline.