Usually, yes
Standard binaural-beat stimulation presents one frequency to one ear and another frequency to the other. Headphones are the simplest way to preserve that separation.
What about speakers?
Stereo speakers can create channel separation, but room acoustics and crosstalk mean both ears usually receive sound from both speakers. That is not equivalent to controlled headphone presentation.
Keep volume moderate
You do not need high volume to perceive tones. Use a comfortable level, take breaks, and avoid listening in situations where reduced environmental awareness would be unsafe.
Related guides
Read how to listen and our practical safety guide.