In 1941, the intriguing possibility that someone could be identified solely by the sound of his or her voice led scientists at Bell Telephone Laboratories to develop the sound spectrograph. First used during World War II by the intelligence services to identify voices broadcast by German military communications, the idea fell into disuse until the early sixties, when the FBI approached Bell for assistance in the grouping of voices. Bell engineer Lawrence Kersta became convinced that voice spectrograms, or "voice- prints" as he called them, could provide a valuable means of personal identification, and after four years of research, he branched out on his own, marketing both the principle and the equipment necessary for its implementation.

Kersta's data was based on recordings of fifty thousand different voices, many of them apparently similar. All showed great differences spectrographically. He even employed professional mimics for his trials, asking them to record imitations of individuals and then comparing the results with recordings of the person imitated. The results on graph and screen were again markedly dissimilar.

The spectrograph records a 2.5-second band of speech on high-quality tape and then scans it electronically, a process that takes ninety seconds. The output is then recorded onto a rotating drum. As the drum revolves, a filter adjusts the various frequencies, enabling a stylus to record their intensity. The resulting print contains a pattern of closely spaced lines showing all the audible frequencies in the tape segment. The horizontal axis registers how high or low the voice is at that point; volume is depicted by the pattern density—the denser the print, the louder the tone. Two kinds of voiceprint can be obtained: bar prints and contour prints. Bar prints are used for identification, whereas contour prints are suitable for computerized filing.

Kersta contends that because the parts of the body used in speech— the tongue, teeth, larynx, lungs, and nasal cavity—vary so much in size and shape among individuals, it is virtually impossible for any two people to have identical features. More easily disputed is his claim that a voice remains constant throughout life. Other experts point out that a person's body—and consequently his or her voice—changes with age. Also, a person's way of speaking may change if he or she moves to a different locality and acquires the accent of its people.

Although the rate of voiceprint acceptance in American courtrooms has been dilatory, it has been used as inceptive evidence by the police and has led to the capture of several criminals. In Europe, the discipline is viewed with skepticism. And yet voice individuality has been recognized elsewhere. U.S. Air Force engineers, eager to improve security in restricted areas, have implemented systems whereby in order to gain access a person must satisfy the computer that his or her voice matches a prerecorded sequence in the computer's memory. So far, the system has a claimed success rate of 99 percent, with professional impersonators able to defeat the system just 1 percent of the time. And it is that 1 percent that makes voiceprints so controversial. 

Clifford Irving

DATE: 1971

LOCATION: Paradise Island, Bahamas

SIGNIFICANCE: Millions of dollars were at stake in one of the most bizarre crimes on record.

In January 1971, a successful author, Clifford Irving, approached the McGraw-Hill Book Company with a literary bombshell: He had been granted access to write the authorized biography of the world's most famous eccentric—Howard R. Hughes. It was a mouth-watering prospect. For decades, the billionaire industrialist had piqued the public imagination, first as an aviator and moviemaker, more recently as a casino magnate whose fabulous wealth and craving for privacy allowed him to indulge an allegedly outlandish lifestyle.

McGraw-Hill's first inclination was to show Irving the door, but when he produced a clutch of letters all purportedly written by Hughes, and which experts verified as genuine, the company realized it had a potential megaseller on its hands. In anticipation of the windfall to come, it advanced Irving $765,000, an unheard-of sum for those days. Irving duly completed a twelve-hundred-page manuscript. Several people familiar with Hughes read the manuscript and vouched for its authenticity. Prepublication serial rights went to Time magazine; everyone stood to make a fortune, or so it seemed.

But then the man at the epicenter of this maelstrom decided that enough was enough. After fifteen years of being incommunicado, Howard Hughes broke his silence to announce that the biography was a fraud—he had never met Irving and had no idea where he had obtained the material for the book, which he dismissed as "totally fantastic fiction."

Hughes imparted these revelations from his Paradise Island sanctuary in the Bahamas via a two-hour teleconference arranged through NBC with selected reporters in a Los Angeles hotel. In typical Howard Hughes fashion, the meeting had been arranged in total secrecy; only later would a transcript be made available to the public. All of the reporters were seasoned veterans who had covered Hughes in his earlier years. Their task was to establish that the ethereal voice at the other end of the telephone line was actually that of Howard Hughes. Twenty minutes were allotted to bombard Hughes with questions about his background in efforts to weed out an impostor. One of the first queries concerned a distinctive cockpit design on one of Hughes's earliest aircraft. The response, cogent and lengthy, revealed a person conversant with all facets of aero-manufacture.

Personal Reminiscences

Other questions were more mundane. "At the time of your round-theworld trip in 1938," asked Marvin Miles of the Los Angeles Times, "a superstitious woman placed a good-luck charm on your airplane. What was it and where was it placed?"

This stumped Hughes completely. After a lengthy delay, he said, "I want to be completely honest with you. I don't remember that one." But even before Miles could finish his next question, Hughes jumped in. Yes, it came back to him now—the well-wisher in 1938 had stuck a wad of chewing gum on the tail of his plane. And so it went, every question answered to the reporters' satisfaction, convincing everyone present that they were talking to the genuine Howard Hughes. Relieved to have that part of the proceedings behind him, Hughes then unleashed a tirade against the alleged biography.

"I only wish I was still in the movie business," he said, "because I don't remember any script as wild or as stretching of the imagination as this yarn has turned out to be. . . . I don't know him [Irving]. I never saw him. I have never even heard of him until a matter of days ago when this thing first came to my attention." About one more point he was equally emphatic— not a single penny of the McGraw-Hill advance had wound up in his bank account.

While eager to accommodate their reticent host, the reporters were also straining at the leash to quiz him about his rumored bizarre appearance. Hughes dismissed stories about waist-length hair and eight-inch fingernails as media inventions. In the future, he said, he intended to adopt a more public lifestyle; perhaps then the press would lose interest in him.

When news of the mysterious teleconference was released, it caused pandemonium. Irving naturally denounced the caller as an impostor, describing the voice as "much too vigorous and deep. . . . For anyone who hasn't seen him for twenty-five years it was an excellent forgery." He closed piously: "My obligation, of course, is to Howard Hughes and not the voice on the telephone."

In anticipation of this charge, NBC had already hired voiceprint pioneer Lawrence Kersta to examine the tapes and decide if this was the real Howard Hughes. Because the fundamental principle of voiceprinting hinges on the comparison of one voice with another, obviously another tape of Hughes's voice—one indisputably his— had to be found. It came from a speech made by the billionaire some thirty years earlier to a Senate subcommittee. Kersta knew that this would provide a searching test of his belief that although voices may change over the decades, their inherent individuality remains constant.

Deliberate Analysis

After several days spent converting the tapes into spectrograms; measuring pitch, tone, volume, and other elements of the voices; and then comparing the voice pictures on a line-by-line basis, Kersta declared himself satisfied that the person speaking on the phone was Hughes and no one else. "We are as near to 100 percent positive as a scientist would ever allow himself to be."

Not everyone was convinced, especially those who felt that Kersta's commercial promotion of voiceprinting might well constitute a conflict of interest. Dr. Peter Ladefoged, professor of phonetics at UCLA and a critic of Kersta's early methods, was asked to review the tapes. Ladefoged had to admit that recent technological advances in voiceprinting had removed many of his doubts. After spending hours with a spectrograph, he announced, "I'm reasonably certain that those recordings are of the same voice. . . . Even considering the age difference, . . . it is difficult to believe that this could be two different voices."

From this point on, Irving's scheme began to unravel with almost indecent haste. A Swiss bank, unwilling to be a party to obvious fraud, broke traditional bank secrecy laws and revealed that a check from McGraw-Hill for $650,000 had been deposited in one bank by "H. R. Hughes" and then switched to another account in the name of "Helga R. Hughes"—actually Irving's wife.

On June 16, 1972, found guilty of forgery and forced to repay what was left of the publisher's money, Irving was sentenced to thirty months in prison. He served just over half the jail term before resuming his career as a writer.

Conclusion

Until his death in 1976, Howard Hughes continued to exert an extraordinary hold on the public imagination. To the end, he remained elusive and shadowy. Like his voice, nothing had changed. 

Brian Hussong

DATE: 1971

LOCATION: Suamico, Wisconsin

SIGNIFICANCE: A murder of terrifying brutality was solved through the inventive use of voiceprint technology.

Neil LaFave loved his work as a game warden. Long days spent patrolling the Sensiba Wildlife Area near Green Bay, Wisconsin, occasionally enlivened by brushes with poachers, made for a good life, one he wouldn't have swapped with anyone. If there was a special urgency in his step on the afternoon of September 24, 1971, it was understandable. Today was his birthday—he was thirty-two years old—and his wife, Peggy, had planned a party for after work. Neil reckoned it wouldn't take long to post the "closed" signs around this last stretch of waterfowl terrain, plenty of time to be home by six.

By 6:30 P.M., Peggy was eyeing the clock nervously. No sign of Neil. She did her best to placate the guests as they arrived, but there was no disguising her edginess. Eventually, with no sign of the guest of honor, they left, giving Peggy a chance to contact Neil's boss, Harold Shrine. He, too, was puzzled; Neil should have been finished hours ago. Straightaway he drove out to the waterfowl reserve.

All of the "closed" signs were in place, but there was no trace of the young warden. Shrine searched until darkness and then called Peggy. It was time to contact the police. After a fruitless nightlong vigil with powerful searchlights, daylight brought the searchers their first clue—LaFave's green pickup truck, door ajar, empty.

Nearby was an ominous pool of blood, some shattered sunglasses, and two spent .22 caliber shells. Tracing a grisly trail of blood and what looked like human matter, searchers found fragments of bone, and then a tooth, until they reached an area of freshly dug ground. Just a few inches below the surface lay the decapitated body of Neil LaFave. The head, found close by in another shallow grave, had been hacked off with a spade or something similar. Two shots to the skull and several more to the body had ended LaFave's life before the mutilation began.

Such extreme barbarism, police felt, amounted to a clue. This was no random killing. Sergeant Marvin Gerlikovski, the officer in charge of the investigation, aware of LaFave's reputation for tenacity—he had arrested dozens of poachers—suspected that this murder had been motivated by revenge. He ordered that everyone ever arrested by LaFave be tracked down and interviewed. This was no easy task. Many had left the area, and others were reluctant to cooperate, but gradually the number was whittled down. Those unable to satisfy the interrogators were asked to submit to a polygraph examination. With varying degrees of enthusiasm all complied— except one.

Bitter Feud

It was no secret that Brian Hussong hated the dead warden. He and LaFave had been crossing swords for years. No matter how many times he was arrested, the twenty-one-year-old Hussong kept on poaching. Just recently LaFave had caught him again, shooting pheasants. Hussong, sullen and unresponsive, was evasive when questioned about his whereabouts on the day of the murder. He knew his rights, too; when asked if he would undergo a polygraph test, he refused point-blank.

Stymied on this tack, Gerlikovski followed his instincts and applied for a court order to place a wiretap on the house where Hussong lived with his girlfriend, Janice Obey. Sure enough, before long Hussong was overheard discussing guns and alibis with both Janice and his mother, Mary. Even more damning was a conversation with his eighty-three-year-old grandmother, Agnes Hussong, in which she assured him that his guns were hidden where no one could find them.

So stunned was this elderly matriarch when detectives came knocking at her door that she led them straight to the cache of firearms. These were shipped to the state crime laboratory in Madison for testing, where ballistics expert William Rathman confirmed that one of the guns recovered had fired those spent .22 caliber shells found near LaFave's body. On December 16, 1971, nearly three months after the murder, Hussong was taken into custody.

As a precautionary measure, Gerlikovski had recorded all of the phonetap conversations from Hussong's house and passed these tapes to Ernest Nash, head of the Michigan Voice Identification Unit, at that time the nation's most sophisticated voiceprint laboratory.

During testimony, Agnes Hussong bitterly denied ever saying she had hidden her grandson's guns, or that she even had them at all. It was the denial that prosecutor Donald Zuidmulder had both expected and prepared for. He immediately summoned Nash to the stand. Nash first explained the principles behind voiceprinting, then declared himself in no doubt that it was Agnes Hussong's voice on the tape in which she admitted hiding the firearms. All of the other voices on the tapes were similarly identified as belonging to close relatives of Hussong. It was unanswerable.

After three and a half hours of deliberation, during which they asked to hear the tapes again, the jury delivered a guilty verdict. Hussong received life imprisonment. In August 1981, Hussong broke out of Fox Lake Correctional Institution. He remained at large for three months, holed up in a remote cabin, until December 10, when he was killed in a shootout with the police.

Conclusion

This was the first occasion on which Wisconsin had sanctioned the use of wiretaps on the residence of a murder suspect. Given the outcome, it is perhaps surprising that the practice has not become more widespread.

Jimmy Wayne Glenn

DATE: 1973

LOCATION: Modesto, California

SIGNIFICANCE: As a forensic tool, the Psychological Stress Evaluator has been controversial, but few could dispute its usefulness in helping establish the identity of this savage murderer.

All morning Bonnie Johnson had been trying to contact her mother on the phone. But every time, the phone just rang. The more Bonnie tried, the more anxious she became, her mind teeming with all kinds of possibilities, none of them pleasant. Her unease only heightened that afternoon—May 1, 1973—when she knocked at her mother's apartment and heard the same stony silence. Convinced that something was amiss, she obtained a passkey from the manager and let herself into the apartment. Her worst fears were realized with the discovery of Gloria Carpenter's lifeless body submerged in the bathtub. Everything pointed to the fifty-nine-year-old beautician's suffering a heart attack while bathing, a common enough occurrence—until it was noticed that two locks on one door were unfastened. No one with Gloria Carpenter's almost obsessive preoccupation for security would have used the bath without first checking that she was safely locked in.

Not until the arrival of Deputy Coroner William Fanter was the true cause of death known. The thin line around Gloria Carpenter's neck, almost invisible to the naked eye, was clear evidence that she had been strangled, most likely by the nylon stocking found on the bathroom floor. She had also been raped. County pathologist Dr. William Ernoehazy fixed the time of death at about 12:30 that morning. A lack of water in the lungs indicated that she was dead before immersion in the bathtub; the killer's attempt to bury his murderous deeds beneath a patina of natural causes had failed dismally. Because there were no signs of forcible entry, and because nothing was stolen, detectives reasoned that the dead woman had probably known her killer.

Piecing together Gloria Carpenter's whereabouts on the night of her death led investigators to a local bar, where patrons remembered her drinking with a loner named Jimmy Wayne Glenn. When interviewed, Glenn readily admitted carousing with Gloria Carpenter and taking her home, but he denied ever entering the apartment. The evening had ended at her front door, he said. Afterward, he had gone home.

At Glenn's apartment, investigators found a large collection of detective magazines; one, lying on a couch, was opened to a murder story in which the details were eerily similar to the killing of Gloria Carpenter. Glenn insisted that it was mere coincidence, but those listening weren't so sure. They knew that many killers had drawn vicious inspiration from such material. However, despite their suspicions, there wasn't a scrap of concrete evidence to connect Glenn with the murder of Gloria Carpenter. It was at this point that the suggestion was made to use a recently invented but as yet unproved device known as the Psychological Stress Evaluator (PSE).

New Technology

Like the polygraph, the PSE seeks to identify deceit. Unlike the so-called lie detector, it does not track changes in heart rate or perspiration but variations in the voice. It also differs in another important respect. Whereas the polygraph has often been criticized because the attachment of bands and wires to the subject can induce stress and therefore yield faulty results, the PSE bypasses physical contact altogether. Instead, the subject merely speaks into a microphone, or his or her voice is recorded on tape for later evaluation. These sources are then fed into a machine that looks similar to a typewriter. The results are printed out in a graph.

Proponents of the technology claim that stress is reflected in the inaudible variations of the voice, and while these differences cannot necessarily be heard, they can be detected and recorded by the PSE. Once a graph of the subject's voice has been produced, a skilled interpreter can examine it for signs of deception.

Although Glenn would have been quite within his legal rights to decline such a test, he blithely agreed. In the presence of a tape recorder, Glenn was again asked if he had entered Gloria Carpenter's apartment on the crucial night. Again he said no. But when his tape-recorded words were fed into the PSE, the needle swung wildly. The extremes recorded, while enough to convince experts that Glenn was lying, would not be admissible in court, but they did have the effect of steering every investigative effort in one direction—Jimmy Wayne Glenn.

Those efforts were rewarded when a second, more painstaking examinationof the bathroom revealed something that had been missed earlier—a faint palm print on the bathtub rim. It matched that of Glenn. Presentation of this evidence to Glenn triggered an abrupt change of story. Yes, he had been in the apartment on the night in question, and other times, as well. And it was on one of those occasions, he said, that he had slipped on the wet bathroom floor and grabbed the tub rim to pull himself upright.

Revisionism of this order received a frosty reception from the jury. They found Glenn guilty of murder, and he was jailed for life.

Conclusion

Although it is unlikely that any court would admit PSE analysis into testimony, its value has been clearly demonstrated on several occasions. Often the accused, when presented with the PSE results, will cut his or her losses and confess.