"Special" / career highlights series consists of materials that marked significant achievements or career milestones, were designated by the creator to be of particular interest or are of a personal nature. A portion of the materials were originally in a folder marked "Special" and have been arranged into three subseries imposed by the archivist in order to preserve the original order by the creator. The subseries are: Personal, Highlights, and Sound.

The Personal subseries contains a ten-page biography written by one of Belar's daughters. There is his 25 years of service at RCA certificate and dinner program from 1953, as well as his certificate from Sigma Xi. In 1966 upon Belar's retirement he was given a retirement farewell booklet containing many letters from colleagues reflecting on their careers together and wishing him well in retirement. There is a report titled "The Herbert Belar Electron Bugle report" which appears to be humorous in nature, bound like an official report, but intended as a joke. In 1968 RCA celebrated its 25 Anniversary of RCA Laboratories with a commemorative book. The book was sent to Belar with a thank you letter from the RCA President Jim Hillier and Vice President, George Brown. There are two recordings on reel-to-reel, one is of Christmas Carols, and the other is children voices and was re-recorded from a wire recorder. The latter is dated between 1945 and 1948. There is one phonographic record, an RCA Red Label of Claude Debussy's Clair de Lune, recorded in 1947.

Highlights subseries has an album of thirty-two of Belar's patents and an album of newspaper clippings and magazine articles about Belar's work, primarily related to the electronic music synthesizer and the phonetic typewriter. The articles date from 1954 to 1982. There are few full magazines included and the page of the article that references Belar is notated on the front cover. Both albums were originally in 3-ring binders and were removed from the binders for preservation purposes, the original order of the albums has been maintained. There are three additional files included in this series. Belar's personnel file which contains promotion letters, organizational charts, employment agreements, and job descriptions. The folder on File systems is a copy of ledgers that documents Belar's research from 1948 to 1963. There is one folder of information related to Belar's work on the MAD Project and it contains a few brief summaries about the project and a chronology.

Sound subseries primarily relates to the music synthesizer, but does contain some materials on "hi fi," sound on film, and the phonetic typewriter. The first three folders were bound together: Origin of Stereographic Sound; Origin of High Fidelity; and Synthesis of Music. These folders contain research articles and, in some cases, an additional handwritten note. There are several recordings of the music synthesizer between 1952 and 1961. There are four phonographic records and five sound tape reels. The sound tape reels have an accompanying handwritten explanation written by Belar in 1995 at the request of his daughter. There are letters from Belar he wrote to M.W. Scheldorf in response to an inquiry about sounds of music. In 1955 RCA released a four phonographic record box set with a booklet titled; "The Sounds and Music of the RCA Electronic Music Synthesizer." It features narration about the characteristics of musical sounds and musical excerpts demonstrating the synthesizer. Additionally, there is a 16mm film which contains a test method for audio sound on film. There is a videocassette (VHS) copy of the film in the collection. Finally, there is a script for practicing the phonetic typewriter.