An ultralight Graphene Oxide/Polyvinyl Alcohol (GO/PVA) aerogel is proposed as a new class of acoustic materials with tuneable and broadband sound absorption and transmission loss. The interaction between GO sheets and PVA molecules are exploited in our environmentally friendly manufacturing process to fabricate aerogels with hierarchical and tuneable porosity embedded in a honeycomb scaffolding. The developed aerogels show an enhanced dissipation of sound energy, with an extremely low density of 2.10 kg m-3 , one of the lowest values ever reported for acoustic materials. We have first experimentally evaluated and optimized the effects of composition and thickness on the acoustic properties, namely sound absorption and sound transmission losses. Subsequently, we have employed a semi-analytical approach to evaluate the effect of different processing times and find the relationships between the acoustic and non-acoustic properties of the materials. Over the 400 – 2500 Hz range, the reported average sound absorption coefficients are as high as 0.79 for low density aerogels, while the average sound transmission losses can reach 15.8 dB for higher density aerogels. We envision our subwavelength aerogel-based design, tailored at achieving optimal acoustic performance, as a novel lightweight material for advanced engineering applications.