This paper aims to describe pre-aspirated and post-aspirated stops in an endangered language, Scottish Gaelic. Our small-scale study investigates several acoustic parameters of Scottish Gaelic stop consonants designed to measure the duration and noisiness of aspiration of the stop in its immediate phonetic context. Our study expands on previous phonetic descriptions of phonemic (pre)aspiration in three ways: firstly, we provide a more complete durational description of Scottish Gaelic than previous work in the literature; secondly, we apply a new measure, band-pass filtered zero crossing rate (Gordeeva & Scobbie 2010), in order to examine the noisiness of aspiration in addition to durational characteristics. The results from this measure are presented in tandem with durational results in order to assess its usefulness for future research. Thirdly, we consider the possibility of change in the Scottish Gaelic stop system by examining data from older and younger speakers. Results suggest that band-pass filtered zero crossing rate is a useful tool and should be considered in future research on aspiration. Also, durational and zero crossing results indicate that younger speakers have shorter and less noisy pre-aspiration than older speakers. We discuss these results as a possible sound change in progress.