Actual issues of installation in phonoscopic examination

Phonoscopy is a type of special research in forensic science that studies the trace of sound. Phonoscopy of a person’s voice allows you to establish the social characteristics of the person who is talking (education, profession, level of culture); emotional state (rest, agitation, longing); region of oral speech formation (dialect, accent); physical (biological) characteristics (sex, age, height); psychophysiological features (deviation from the norm in various diseases) and methods of pronunciation (reading, recitation, calm speech), as well as an approximate image of the face that is talking. Phonoscopic studies aid in personality identification.

Three important stages can be distinguished in the history of phonoscopy:

  • invention of sound recording and reproduction devices;
  • invention of devices for visualization of oral speech;
  • transfer of sound characteristic from original (material) to digital (computer) form.

A key step in the development of phonoscopy was the invention of the device, which made it possible to see a speech signal in a form that vividly displayed the articulation and voice of the speaker’s face. It was with the invention of such a device that the second half of the word “phonoscopy” became a reality. During the 1920s and 1930s, during a time of significant revival in the scientific world, scientists from different countries proposed many options for visualizing speech signals. After lengthy tests and the natural selection of the best method, by the end of World War II, a device was invented, the fact of the existence of which was kept secret for a long time due to its military significance. Only in November 1945, in the weekly publication Science, in the article Visible Images of Sound, did Ralph Potter for the first time lift the veil of secrecy over a new tool that was developed by Bell Telephone Laboratories. At first it was called a sound spectrograph, but later another name was assigned to it – “sonograph.”

Phonoscopy is not limited in forensic science only to the identification of a person’s speech. This is a basic, decisive issue, but it usually always entails solving a number of other issues, among which the following are most often found:

  • examination of magnetic phonogram installation signs;
  • study of signs of copying phonograms;
  • identification of magnetic phonogram tape recorder;
  • diagnostics and identification of sound recording environment;
  • high intelligibility of the speech signal, curvature by pulse noise or extraneous sounds.

Speaking about the problem of automatically solving problems that stand when identifying a face by pronunciation, the following should be noted. To provide in the algorithmic scheme the study of the signal all the nuances, from the technical features of the quality of the phonogram to the deliberate distortion of the voice of the face, which, unfortunately, even our time is almost impossible. Therefore, the main actor in solving the issue was, is and, taking into account the available factors, and a highly educated and well-trained expert phonoscopist will remain. By examining and carefully examining the speech signal from all sides using powerful modern computer technologies, only such an expert phonoscopist can correctly (without errors) solve all the main problems of phonoscopy.

So again, it would seem, questions of superficial significance, but with what serious theoretical and practical contradictions, personalities and collisions. Therefore, in order to find out in which direction to move and what principles underlie, let’s turn to our own professional analysis.

Therefore, when considering criminal and civil cases, where material evidence is the materials of the video recording, the investigator or judges need to decide on their reliability. To this end, experts are asked about the establishment of the originality of phonograms and whether they succumbed to any changes when recording or after it. Some of the problems of this examination, which lie both in the methodological and technical planes, interfere with the correct assessment by investigators or judges of the conclusions of experts. These issues include studies of phonograms of video sound recording for editing, one of the most studied types of changes in the properties of phonograms using technical means. What is the misunderstanding?

1. On the methodological side, some experts define the very concept of “installation” as “artificial (intentional) selection of information in a certain sequence on a magnetic phonogram, consisting in the removal, addition or movement of individual fragments of the record.” Such a point of view is generally inherent mainly in investigators, judges, lawyers, that is, non-specialists in the technical study of installation, and includes a legal feature (assessment) – the definition of “artificial (intentional).” Thus, they unreasonably relieve themselves of the obligation to give a legal assessment to the fact investigated by experts. Undoubtedly, the concept of “phonogram editing” and “phonogram falsification” are not identical, even from a legal point of view.

There are also cases of refusal of experts to resolve the issue of editing, since, from their point of view, it requires establishing the premeditation of actions with the original phonogram. But the examination does not exist in order to give a legal assessment, but in order to establish the method and technical conditions for making a phonogram, making changes to it. Therefore, it is necessary to introduce into scientific and practical use such a concept of “installation” that would allow solving expert problems without “going beyond the competence” of this examination. And in the expert practice of the Kyiv NDISE, the following definition is applied: “The installation of a phonogram is the process of combining, using technical means, individual parts of a phonogram into a single whole with a violation of the continuity and sequence of displaying the environment.”

But any changes in the properties of the phonogram during its recording and after it can be covered by this concept. For example, recording filtering is definitely not editing. Thus, the main sign of phonogram editing is the formation of a whole of parts.

2. On the technical side, the installation is divided into three main types: mechanical, electronic (analog) and digital (discrete).

Mechanical installation – combining a phonogram from parts by mechanically connecting parts of its carrier (gluing parts of a magnetic film), described in sufficient detail in the literature, is set at the level of visual and magneto-optical control. It should only be noted here that the recording mechanically mounted is fundamentally different from the recording made on the mounted carrier film.

Electronic editing refers to the combination of a phonogram from parts of an analog (continuous) display of information about the environment, that is, an analog signal. Today, the most common is a breakdown in the continuity and sequence of the shape of magnetic fields or the reproduced electronic signal. Therefore, determination of such features is possible at the level of control of magnetic fields directly by means of magneto-optical methods or control of output signal by means of organoleptic and spectral methods.

Not only computers, but also digital voice recorders, mini disk recorders, memory answering machines and the like can be used here. Since information can be recorded immediately in digital form in memory and from there extracted and processed for the purpose of installation, the question arises of developing effective methods for its research. In this direction, staged scientific work was carried out by specialists of the Kharkov NDISE, but the issue of developing the methodology remained open.

In the best way, audio information can be processed using a computer, and this requires a regular PC with a sound card and fairly common audio processing software packages. In this case, sound images can be changed, other sounds are superimposed, a sound background is added, a non-sound environment with its own frequency characteristics, reverb and the like is created. In addition, the mounted phonogram can then be rewritten to a magnetic medium, thus creating the illusion that the material was immediately recorded on it. Such editing, which can mask its features, is already available to the mass user of computer equipment with some sound processing skills and will certainly become relevant in the near future.

If experimental samples cannot be obtained, free samples can be presented for comparative research – magnetic recordings of conversations, conversations where the person being tested is forced to pronounce certain words and expressions, such recordings can be made, for example, during investigative actions.

The expert also needs to be informed when this sound recording was made, what equipment was used for this and what its technical condition was, the type of power supply during recording (power grid, battery, battery), the room plan indicating the location of the tape recorder, microphone and recording participants. Among the main tasks of phonoscopic examination are the identification of a person by voice, as well as the identification of sound and video recording equipment.

The following questions are raised about the decision of the diagnostic phonoscopic examination:

  • how many people participated in the conversation on the phonogram;
  • whether the speech presented on the phonogram is free or fragments of it are memorized, read or free;
  • what is the literal content of the text: what is the meaning of an illegible recording on the presented phonogram;
  • the sources and nature of the sounds accompanying the main recording; what was the environment at the time of making the phonogram (the nature of the room in which the recording took place, recording in an open area, etc.);
  • whether the represented phonogram (video monogram) is the original (copy), and if a copy, then which (first, second, etc.);
  • contains a phonogram (video) of continuous recording or with stops (tape recorder, video recorder, video cameras);
  • what type of magnetic tape was used; was used to record a new or one that had already had a record;
  • whether the presented ​​fonogramma (video) has undergone installation (gluing, electroacoustic installation, etc.), and if so, which part of it is mounted; There are signs of other changes made to the recording process after it ends. or simultaneously recording the sound and image on the video image presented;
  • whether the ​​predstavlennaya to examine the phonogram is made on one or different sound recorders;
  • on the tape recorder (video recorder, voice recorder) of which type, brand, class, country of manufacture this magnetic recording was carried out, the microphone of which type was used for recording;
  • whether, judging by the recording, the sound recorder or microphone, and which ones; and whether technical means were used to deliberately distort the voice;
  • what is the technical level of skills of the phonogram manufacturer;
  • in which area oral speech was formed and in which possible places the person whose speech was recorded lived for a long time;
  • what gender, age, anatomical features of the speech apparatus, physical and mental characteristics of the person whose speech is represented ​​na the phonogram;
  • what are the special social characteristics of the person (level and education, development, intelligence, level of culture, etc.) whose speech is presented ​​na the phonogram;
  • emotional state of the face during the recording of his oral speech.

The following questions are raised for the permission of the identification phonoscopic examination: 1) whether the spoken speech recorded in the phonogram belongs to this person (s), which fragments of sound recording belong to which persons: 2) whether the ​​dannaya of the phonogram is made on the recording apparatus presented, or whether it was played on some kind of tape recorder (video recorder, voice recorder); which of the presented tape recorders (video recorders, voice recorders) recorded or reproduced this phonogram; whether it is a copy made by recording from a laser disc to a given video recorder; 3) is the video number 1 fully or partially a copy of the video number 2; are there any duplicates of No. 1 and No. 2 made by copying from the same No. 3 video; 4) were the glued fragments of this magnetic tape previously one whole?

Phonoscopic examinations have already ceased to be unique. Currently, they are held in state expert institutions of the Ministry of Justice and the Ministry of Internal Affairs of Ukraine.

To solve diagnostic and identification problems, an international examination is appointed, the success of which is largely determined by the quality and number of samples for comparative research provided to the expert by the investigator and the court. In order to obtain qualitative experimental samples, its individual linguistic and phonetic features are detected on the phonogram of the person being installed. At the same time, the materials submitted for comparative research should contain, first of all, words and phrases in which the features of pronunciation, pathology of the language or other deviations from the generally accepted norms of the literary language are most clearly manifested. At the same time, it is desirable to establish in advance with the help of which recording equipment and under what acoustic conditions the examined tape recording was performed. High-quality experimental samples are obtained subject to the following conditions: the microphone is located at a distance of about 0.5 meters from the person’s mouth, and the windows and doors of the room where the recording was made must be tightly closed, the telephones are disconnected, other sources of possible extraneous noise are eliminated, and the magnetic tape must be recorded when, by whom and in whose presence the comparative material was selected. For this, a specialist is invited.

The process of obtaining comparative samples is carried out in such a way that when recording a phonogram, the subject is forced to pronounce the same phrases and words as in the recording under study. In this case, it is necessary to adhere to the same recording conditions, use the same (at least similar) equipment that was used to record the phonogram under study. If necessary, copies can be made from the original and used for more detailed familiarization, etc. This preserves the quality of the recording.

If experimental samples cannot be obtained, free samples can be presented for comparative research – magnetic recordings of conversations, conversations where the person being tested is forced to pronounce certain words and expressions, such recordings can be made, for example, during investigative actions.

The expert also needs to be informed when this sound recording was made, what equipment was used for this and what its technical condition was, the type of power supply during recording (power grid, battery, battery), the room plan indicating the location of the tape recorder, microphone and recording participants.

I cannot help but notice that when issues of phonographic examination arise in court, the following factors become decisive: at the request of the interested party, the feasibility of conducting this type of examination is determined; instructions of the institution for conducting the examination and a special unit, if any, on issues of this nature of the analysis; a list of questions to the expert or collegial expert body is formed; take into account the counterarguments of the other party to the dispute, which, in certain specified circumstances, refuses to obtain evidence such as expertise and proposes alternative measures to form an evidence base, referring to the delay in the trial, refuting the court’s satisfaction with the request for expertise; the low level of professionalism of experts in this area; difficulty in providing unambiguous conclusions; lack of special equipment in expert institutions, allowing to obtain correct objective results in the form of an expert opinion and the like.

Under such circumstances, the subject of the claim, pretentious demands, to obtain significant theoretical training on this issue, to obtain advice from specialists, and also does not prevent obtaining an alternative in the form of a preliminary opinion from a specialist in this field, which must be presented to the court by attaching it to the list of evidence in this case. This type of evidence is not decisive and is accepted by the court in the understanding of Art. 32-36 of the Economic Procedure Code of Ukraine, as one of the evidence in the case. However, this will significantly affect the theoretical and practical training of both the judges in the case and the desire of the party to clarify and transparency during the hearing of the case, ruling on the merits and rejecting or satisfying various kinds of petitions from the parties.