Purpose: A frequent complaint by older adults is difficulty communicating in challenging acoustic environments. The purpose of this work was to review and summarize information about how speech perception in complex listening situations changes across the adult age range. Method: This article provides a review of age-related changes in speech understanding in complex listening environments and summarizes results from several studies conducted in our laboratory. Results: Both degree of high frequency hearing loss and cognitive test performance limit individuals' ability to understand speech in difficult listening situations as they age. The performance of middle-aged adults is similar to that of younger adults in the presence of noise maskers, but they experience substantially more difficulty when the masker is 1 or 2 competing speech messages. For the most part, middle-aged participants in studies conducted in our laboratory reported as much self-perceived hearing problems as did older adult participants. Conclusions: Research supports the multifactorial nature of listening in real-world environments. Current audiologic assessment practices are often insufficient to identify the true speech understanding struggles that individuals experience in these situations. This points to the importance of giving weight to patients' self-reported difficulties. Presentation Video: http://cred.pubs.asha.org/article. aspx?articleid=2601619This research forum contains papers from the 2016 Research Symposium at the ASHA Convention held in Philadelphia, PA.T he primary complaint of most adults with hearing impairment is difficulty understanding speech in noisy situations (Committee on Hearing Bioacoustics and Biomechanics, 1988;Pichora-Fuller, 1997). The most problematic situations reported by patients tend to be those that involve more than one intelligible talker. This is consistent with research demonstrating that older adults perform poorer than younger adults on laboratory-based tasks in which there are multiple speech sources, particularly when the competing speech is comprehensible (Helfer, Chevalier, & Freyman, 2010;Tun, O'Kane, & Wingfield, 2002).Why do these competing speech situations become more challenging as individuals age? The ability to understand a message in the presence of competing speech involves multiple levels of both peripheral and higher level processing, from segregating the message of interest from nonessential background signals to focusing and maintaining attention on the target stream, to decoding, understanding, and encoding the information into memory. Problems at any of these levels can lead to misunderstanding.An important contributor to these listening difficulties in adverse situations is the peripheral hearing loss that typically accompanies aging. High-frequency hearing loss attenuates and distorts the incoming acoustic signal and is the primary cause of problems understanding speech in noise (Arbogast, Mason, & Kidd, 2005;Marrone, Mason, & Kidd, 2008). However, other intrinsic variables als...