Participants in the experimental group will listen to instrumental music embedded with 7 Hz binaural beats (theta range) generated using Gnaural (GPL-2.0 licensed, programmable sound generator). The tracks include piano and instrumental music played at a volume of 50-60 dB, allowing communication with the healthcare provider. Music will be delivered via headphones for approximately 30 minutes (20 minutes before and during the procedure). STAI-I and STAI-II scores will be assessed pre- and post-procedure.

Participants in the control group will receive standard care during IUD insertion. No music or other additional intervention will be applied. STAI-I and STAI-II scores will be measured before and after the procedure.

Modern 'relaxation' music regularly includes binaural beats. Binaural beats can be defined as a sensation produced by the arrival of sine tones of different frequencies in each ear. This sensation is created by the difference in frequency between the two tones reaching the ear. Music with binaural beats has been associated with reduced anxiety and increased relaxation by activating theta and delta wavelengths in the electroencephalography (EEG). The authors used Gnaural (GPL-2.0), a freely programmable sound generator, for the binaural beats. Two pieces of instrumental 7 Hz binaural beats were used, a piano and an instrumental. The music volume was between 50-60 decibels and was at a level where the participant could hear the healthcare professional performing the procedure.

Anxiety severity will be measured using the State Anxiety subscale of the Spielberger State-Trait Anxiety Inventory (STAI-S). Participants will respond to 20 items using a 4-point Likert scale (1 = Not at all, 2 = Somewhat, 3 = Moderately so, 4 = Very much so).

Trait anxiety will be measured using the Trait Anxiety subscale of the Spielberger State-Trait Anxiety Inventory (STAI-T), consisting of 20 items rated on a 4-point Likert scale. This scale assesses the participant's general tendency toward anxiety.