Approximate Nearest Neighbor Phrase Mining for Contextual Speech Recognition

This paper presents an extension to train end-to-end Context-Aware Transformer Transducer ( CATT ) models by using a simple, yet efficient method of mining hard negative phrases from the latent space of the context encoder. During training, given a reference query, we mine a number of similar phrases using approximate nearest neighbour search. These sampled phrases are then used as negative examples in the context list alongside random and ground truth contextual information. By including approximate nearest neighbour phrases (ANN-P) in the context list, we encourage the learned representation…Apple Machine Learning Research

Near-Optimal Algorithms for Private Online Optimization in the Realizable Regime

*=Equal Contributors
We consider online learning problems in the realizable setting, where there is a zero-loss solution, and propose new Differentially Private (DP) algorithms that obtain near-optimal regret bounds. For the problem of online prediction from experts, we design new algorithms that obtain near-optimal regret where is the number of experts. This significantly improves over the best existing regret bounds for the DP non-realizable setting which are . We also develop an adaptive algorithm for the small-loss setting with regret where is the total loss of the best expert…Apple Machine Learning Research

Semi-Supervised and Long-Tailed Object Detection with CascadeMatch

This paper focuses on long-tailed object detection in the semi-supervised learning setting, which poses realistic challenges, but has rarely been studied in the literature. We propose a novel pseudo-labeling-based detector called CascadeMatch. Our detector features a cascade network architecture, which has multi-stage detection heads with progressive confidence thresholds. To avoid manually tuning the thresholds, we design a new adaptive pseudo-label mining mechanism to automatically identify suitable values from data. To mitigate confirmation bias, where a model is negatively reinforced by…Apple Machine Learning Research

Less Is More: A Unified Architecture for Device-Directed Speech Detection with Multiple Invocation Types

Suppressing unintended invocation of the device because of the speech that sounds like wake-word, or accidental button presses, is critical for a good user experience, and is referred to as False-Trigger-Mitigation (FTM). In case of multiple invocation options, the traditional approach to FTM is to use invocation-specific models, or a single model for all invocations. Both approaches are sub-optimal: the memory cost for the former approach grows linearly with the number of invocation options, which is prohibitive for on-device deployment, and does not take advantage of shared training data;…Apple Machine Learning Research

Collaborative Machine Learning Model Building with Families Using Co-ML

Existing novice-friendly machine learning (ML) modeling tools center around a solo user experience, where a single user collects only their own data to build a model. However, solo modeling experiences limit valuable opportunities for encountering alternative ideas and approaches that can arise when learners work together; consequently, it often precludes encountering critical issues in ML around data representation and diversity that can surface when different perspectives are manifested in a group-constructed data set. To address this issue, we created Co-ML – a tablet-based app for learners…Apple Machine Learning Research

Efficient Multimodal Neural Networks for Trigger-less Voice Assistants

The adoption of multimodal interactions by Voice Assistants (VAs) is growing rapidly to enhance human-computer interactions. Smartwatches have now incorporated trigger-less methods of invoking VAs, such as Raise To Speak (RTS), where the user raises their watch and speaks to VAs without an explicit trigger. Current state-of-the-art RTS systems rely on heuristics and engineered Finite State Machines to fuse gesture and audio data for multimodal decision-making. However, these methods have limitations, including limited adaptability, scalability, and induced human biases. In this work, we…Apple Machine Learning Research

Application-Agnostic Language Modeling for On-Device ASR

On-device automatic speech recognition systems face several challenges compared to server-based systems. They have to meet stricter constraints in terms of speed, disk size and memory while maintaining the same accuracy. Often they have to serve several applications with different distributions at once, such as communicating with a virtual assistant and speech-to-text. The simplest solution to serve multiple applications is to build application-specific (language) models, but this leads to an increase in memory. Therefore, we explore different data- and architecture-driven language modeling…Apple Machine Learning Research

Unconstrained Channel Pruning

Modern neural networks are growing not only in size and complexity but also in inference time. One of the most effective compression techniques — channel pruning — combats this trend by removing channels from convolutional weights to reduce resource consumption. However, removing channels is non-trivial for multi-branch segments of a model, which can introduce extra memory copies at inference time. These copies incur increase latency — so much so, that the pruned model is even slower than the original, unpruned model. As a workaround, existing pruning works constrain certain channels to be…Apple Machine Learning Research