The driver size differs between the two (9 mm vs 10 mm), which can influence sound depth, bass response, and overall audio clarity. Both headphones offer solid battery performance, making them suitable for long listening sessions and travel. Sony MDR-EX15LP and Aiwa ESTM-51 offer different noise cancellation capabilities (No vs NA), which can impact how effectively they block external noise. There is a noticeable difference in weight (3 g (without cable) vs 15 Gm), which may affect comfort during extended use. If you're comparing Sony MDR-EX15LP and Aiwa ESTM-51, both models offer a strong combination of sound performance, comfort, and modern wireless features. Impedance levels vary (16 ohms vs NA), which can affect compatibility and audio output when used with different devices. In general, both options are suitable for everyday use including music, calls, travel, and work-from-home scenarios. The frequency response differs (8 - 22,000 Hz vs 20 Hz - 20000 Hz), which can influence how well the headphones reproduce lows, mids, and highs. Both models support modern Bluetooth connectivity, ensuring stable wireless performance with compatible devices.

Verdict: Both headphones offer strong performance, and the right choice depends on your priorities such as battery life, comfort, and noise cancellation.