The process of language acquisition requires an individual to organize the world through a system of symbols and referents. For children with severe intellectual disabilities and language delays, the ability to link a symbol to its referent may be a difficult task. In addition to the intervention strategy, issues such as the visual complexity and iconicity of a symbol arise when deciding what to select as a medium to teach language. This study explored the ability of four pre-school age children with developmental and language delays to acquire the meanings of Blissymbols and lexigrams using an observational experiential language intervention. In production, all four of the participants demonstrated symbol-referent relationships, while in comprehension, three of the four participants demonstrated at least emerging symbol-referent relationships. Although the number of symbols learned across participants varied, there were no differences between the learning of arbitrary and comparatively iconic symbols. The participants' comprehension skills appeared to influence their performance.