The frequency response differs (20 - 20,000 Hz vs 18 - 18000 Hz), which can influence how well the headphones reproduce lows, mids, and highs. Impedance levels vary (20 ohms (when noise cancelling function is used) vs 32 ohms), which can affect compatibility and audio output when used with different devices. Audio Technica ATH-ANC25 and Sennheiser HD 203 offer different noise cancellation capabilities (Yes (Reduces Noise up to 15 dB) vs No), which can impact how effectively they block external noise. Both headphones offer solid battery performance, making them suitable for long listening sessions and travel. Both headphones are equipped with capable drivers that deliver balanced sound output suitable for music, calls, and entertainment. From a usability standpoint, both models provide a reliable and premium headphone experience. Audio Technica ATH-ANC25 and Sennheiser HD 203 are well-known options in the wireless headphone segment, offering a balance of audio quality, battery performance, and smart features. There is a noticeable difference in weight (104 g (Inclusive of Battery and Cable) vs 362 g), which may affect comfort during extended use. Both models support modern Bluetooth connectivity, ensuring stable wireless performance with compatible devices.

Verdict: Choosing between Audio Technica ATH-ANC25 and Sennheiser HD 203 depends on whether you value better sound, longer battery life, or enhanced features.