The frequency number is not enough
Two recordings can both be described as 40 Hz while differing in carrier tones, modulation, channel separation, pulse shape, loudness, and background layers. Those differences may matter to the listening experience and to how a study can be replicated.
Details that improve transparency
- Stated beat or modulation frequency.
- Carrier frequency and left/right channel arrangement.
- Session length and recommended repetition.
- Whether the stimulus is audio-only or multisensory.
- Any independent acoustic or EEG testing.
The buyer implication
When a product does not disclose these details, a reviewer cannot say that it matches a cited protocol. The correct wording is that the product is inspired by a research theme, not that it reproduces the research.