Voice recordings can be changed in various ways, either intentionally or unintentionally, one of
which is by using a voice changer. Reference voice recordings and suspect voice recordings will be
more difficult to analyze if suspect voice recordings are changed using a voice changer application
under certain effects such as telephone effect. Voice Changer can be one form of activity that can
be carried out by anti-forensics, making it difficult for investigators to investigate if the voice
recording is changed with telephone effect. This study has two types of recordings, namely the
reference voice recording (unknown sample) and suspect voice recording (known sample) that has
been changed using a voice changer application with telephone effect. Investigations were carried
out based on data results extraction and analysis using pitch, formant, and spectrogram using the
Analysis of variance (ANOVA) method and the likelihood ratio method. The results of this study
indicate that the application of voice changer can be one form of activity that can be carried out by
anti-forensics so that it can be difficult for investigators to conduct investigations on sound recording
evidence. This research may help forensic communities, especially investigators to conduct
investigations on sound recording.