Photo/Illutration The image compares sounds made by gunshots and fireworks. The two bars on the left show sounds made by the homemade handgun used to shoot former Prime Minister Shinzo Abe, and the others, from center, a Beretta pistol, a Desert Eagle Magnum pistol and a firework. In each bar, the pitch of sound is shown as the widest red-colored width. (Provided by the Japan Acoustic Laboratory)

The two gunshots heard when former Prime Minister Shinzo Abe was shot dead in Nara in July were not similar to typical gunshot sounds but were more like the sounds of fireworks, according to a recent study.

Hajime Suzuki, 51, a director of the Japan Acoustic Laboratory in Tokyo and an expert of acoustics and audio analysis, concluded that people at the scene might have thought that fireworks were being shot off.

“People recognize various sounds depending on their pitches," said Suzuki, who conducted the study for The Asahi Shimbun. "The gunfire sounds heard at (Abe’s murder) scene were much deeper than a typical pistol sound. I guess it was difficult for people there to instantly recognize (the sound from the gun) as gunshots.”

Tetsuya Yamagami, 41, the suspect in Abe's murder, is accused of using a homemade gun he had manufactured after learning how to make it through online videos.

In the study, The Asahi Shimbun asked the Japan Acoustic Laboratory to analyze the audio data recorded by the paper’s reporter who was at the scene to report on Abe’s speech.

The recording was made with a voice recorder that the reporter put on the corner of a street.

Suzuki analyzed the frequency of sounds contained in the gunshot sounds that Yamagami’s gun made.

Then he compared it to other audio data that the laboratory has on file that it can publicly use.

He found that components of an approximate 100 hertz (cycles per second) frequency sound were most prominently heard in both the gunshots from the handmade weapon. 

He also found that a 550 hertz frequency was most prominent in the sound of a gunshot fired by a handgun by the Italian company Beretta, a firearm used by law enforcement organizations and militaries in many countries.

In addition, a 200 hertz frequency was most prominently heard in a gunshot from a Desert Eagle, a pistol made by a U.S. company in a large-size caliber that can fire a Magnum cartridge.

Suzuki said this means that these commercially produced firearms make a higher-pitched sound than Yamagami’s handmade gun when fired. 

He said that the peaking frequency in the sound made by a type of large Japanese firework called Shakudama is around 70 hertz, a similar frequency to the gunshots heard from Yamagami’s firearm.

A report compiled by the National Police Agency on the security and protection issues at the shooting site said security officers didn’t instantly recognize the sounds of gunshots as those made by a firearm.

The report was published on Aug. 25.

The expert's finding also squares up with the accounts of eyewitnesses at the murder scene, including a mayor and local assembly members, who told The Asahi Shimbun that they didn’t think they were hearing gunshots when Abe was shot.

They compared the sounds to fireworks or a bursting tire.

Related News