SALT & PEPPER: Seasoned tools to better understand speech and language disorders

By Charlene N. Rivera-Bonet, Waisman Science Writer

We might know salt and pepper as the dynamic duo of seasonings that adds flavor to foods, but in the language and speech research world, the duo has a different meaning. SALT is short for Systemic Analysis of Language Transcripts, while PEPPER stands for Program to Examine Phonetic and Phonologic Evaluation Records. The two are computer programs, created by Jon Miller, PhD, CCC-SLP, and Robin Chapman, PhD, and Larry Shriberg, PhD, respectively, used to better understand speech and language, particularly in children.

Miller, Chapman, and Shriberg were among the first researchers to join the Waisman Center when it opened in 1973, and it wasn’t long after they joined that they came up with SALT and PEPPER. Both programs had a big impact on how language and speech research is collected, analyzed, and stored today. “But it was not as easy as salting and peppering,” says Chapman, emeritus professor of communication sciences and disorders.

The origins of SALT & PEPPER

Jon Miller, PhD
Jon Miller, PhD

Back in the 70s, before SALT and PEPPER came to be, “The whole process of assessing a language sample was really an observational method,” says Miller, “because we didn’t have any methods to assess kids’ language and communication for populations [with developmental disabilities].” Miller is an emeritus professor of communication sciences and disorders and speech-language pathologist.

According to Miller, the way a child uses language and words can reveal a lot about how they interpret the world, and how they understand time, space, and other concepts.

The way they studied speech and language in children entailed recording kids having conversations with their parents. “Listening to kids and writing down what they’re saying systematically provided the footprint of how kids were learning language,” says Miller. However, according to Miller, this process was excruciating. They had to manually write down the kids’ responses to the prompts, have it checked by someone else, then count the words by hand. “We realized that we needed something to help the otherwise by-hand analysis of large numbers of transcripts,” Chapman says.

Together, Miller and Chapman developed a computer program that would do all the work. “This was before the Apple [Mac II] came out or before Bill Gates produced his first PC,” Miller says.

Ann Nockerts was hired as a computer programmer supporting several early research projects from which SALT emerged. She wrote all the code for SALT, from its beginning to its current version. “Her work was and is central to documenting communication skills in all children,” Miller says.

After the code was developed, “Jon Miller went on to the very arduous task of developing actual databases from a number of different populations to permit the interpretation of the data,” Chapman explains. “What I contributed to the early effort was mainly a discussion of what variables should be measured by the program and how we might display them.”

The new computer program not only performed the tedious parts of the job such as facilitating the process of transcribing the kids’ words, it reduced the amount of time the analysis took and reduced human error. “Basically, it’s been a labor that has been motivated by getting our research done more effectively and accurately,” Miller says. With the program, they were able to reduce many hours of work to four or five minutes, and increase the language measures they took from three to 50.

Around the same time, Shriberg, emeritus professor of communication sciences and disorders, was interested in learning more about kids who had trouble talking and had unknown causes of speech impairment. “In order to do that, we needed some tools to do analysis of their speech,” Shriberg says. “So, the program PEPPER was about trying to analyze the kids’ speech in a way that can be done sort of objectively as possible. And done in a large-scale way.”

Robin Chapman, PhD
Robin Chapman, PhD

Kids would come into the lab and name pictures in a booklet or screen. Naming objects like spoon, spill, spot, and spider, could help identify the three types of speech errors: deletions, substitutions, or distortions. The recordings were then transcribed into separate sounds and converted into special phonetic symbols for PEPPER.

PEPPER had the ability to, based on the data, identify and classify different speech sound disorders (SSD). With more accurate classification of SSD, clinicians could provide a better diagnosis and decide on the best course of treatment, also selected by PEPPER based on the kid’s data.

While SALT dealt with language – words, sentences, utterances, and text –, PEPPER analyzed speech – sounds, articulations, and acoustics.

The impact of SALT & PEPPER

Analysis of language using SALT could reveal the process of typical vocabulary development, and help pinpoint what is going on in the language development of kids with intellectual and developmental disabilities (IDD).

“[SALT] was elegant and, and set up as elegant and versatile, in a way that serves the needs of many, many language researchers,” says Chapman. Along with Miller, Chapman used SALT to research children, adolescents, and young adults with Down syndrome as well as other IDDs, and how their language skills changed as they grew older.

Instead of using standardized testing, “[SALT] made it actually able to look at their language skills in storytelling, conversation, and interaction with multiple different speakers, and to simultaneously look at the sentence structures they were putting together and the disfluencies mazes in their entire transcripts at the same time,” Chapman explains.

Meanwhile, Shriberg’s goal was to find out what caused SSD and what SSD looked like for different kids. “Give [the disorders] names, give them descriptions that clinicians and researchers can use and then find ways to go about testing that come up with reliable classifications,” says Shriberg.

Lawrence D. Shriberg, PhD
Lawrence D. Shriberg, PhD

The development of PEPPER aided the storage and analysis of speech data for Shriberg’s Phonology Project. In his research, Shriberg looked into understanding the causes of SSD in order to allow clinicians to choose the right treatment for each child. PEPPER is also a space to store data on SSD, to make it available to researchers, clinicians, instructors, and students. “We have fulfilled the mission,” says Shriberg.

Most of the kids that participated in Chapman, Miller, and Shriberg’s labs were part of the Waisman Center Clinics.


Since the creation of SALT in the early 80s, language researchers across the nation started requesting the software to use in their own research.  “As soon as we got it done and told anybody about it, they wanted a copy,” says Miller. Because the demand for technical assistance for SALT users was high, they started charging for the software in order to cover the cost of meeting that need. “So, SALT became an enterprise,” says Miller. Now, SALT is a company that “…continues to meet the needs of clinicians and researchers in the United States and around the world by creating specific analyses for investigators and working with individuals interested in creating transcription and analysis routines for languages other than English.”

SALT has been sold in all 50 states, Puerto Rico, and on US military bases. International sales include more than 32 countries around the world.

PEPPER, over its lifespan, has been expanded and modified to reflect the evolving needs and goals of the Phonology Project. Eight guides have been developed to provide information and tutorials on its use. Currently, PEPPER fonts are used as a research tool in the quest for the genetic origins of SSD in children. The PEPPER program is also used in the Speech Disorders Classification Systems (SCDS), which is one of the three most frequent systems researchers and speech clinicians use to assess and classify children with SSD of known or unknown origin.

Miller and Chapman’s SALT and Shriberg’s PEPPER seasoned research in speech and language by going above and beyond to meet the needs in the field. Through the creation of these two computer programs, which were often times used in combination, they allowed for more effective and accurate study of speech and language disorders in kids, particularly those with intellectual and developmental disabilities.

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